NoRotors.com - RX7 Engine Swap Forum
Technical Information => Drivetrain => Topic started by: bikedad on November 13, 2010, 08:24:15 PM
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So I broke my pinion mount once again. Busted the tab on the cradle that holds the differential mount.
Twice now when doing hard launches and getting a little wheel hop I've slammed the pinion into the floor board.
(https://www.norotors.com/gallery/albums/FC_Diff_Removal/Dir_1/medium_2268.JPG) (http://www.norotors.com/index.php?action=gallery;sa=view;id=2268)
I have the S4 TII differential. Pinion snubber installed and the pinion mount is boxed (made solid)
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Ray (Rayminator) Platek had a nice basic pinion brace that he installed on his LS1 FC. He put 40,000 miles on his car with untold amount of drag launches.
His car was in the mid 11's with a consistent 1.6 sec 60ft and he never had a problem. I gave him a call and he offered to give me a hand.
This is a very basic but bullet proof installation. You will need access to a welder and have some skills in welding.
I pulled my entire cradle out of the car. Ray came over and helped me weld the pinion brace in to the cradle.
2 pieces of 5/16" flat stock cut 7" each. In one piece a 9/16" hole drilled 3/4" centered from one end.
The other piece a 1/2" hole also drilled 3/4" centered from one end. (The difference in hole sizes is to allow about 1/16" play in pinion up down movement.)
A 1/2" Grade 8 bolt with locknut and washer will hold them together at the pivot.
Bolt the differential into the cradle and align the 2 pieces. Clamp and mark to weld the 2 pieces as shown.
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Remove differential and proceed to weld the pieces (on edge) to the cradle and diff mount.
We used a Hobart 130 mig welder with the help of a acetylene torch to preheat the metal for penetration.
The piece on the diff mount could be bolted if desired.
(Sorry for the camera phone pictures)
Bottom of cradle
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Bottom of cradle
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Diff mount
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Welded up and bolted together
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At the pivot it's greased and not tightened to allow movement
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Lock nut and washer to allow movement
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One hole is 1/2", the other hole is 9/16".......grade 8 bolt is 1/2". ;)
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One hole is 1/2", the other hole is 9/16".......grade 8 bolt is 1/2". ;)
Fixed
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I had a similar setup welded in my OLD FC, and it ripped the sheet metal right off the subframe where the brace was welded in. I launched the shit outta the car one night trying to impress an old girlfriend and BANG....
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I had a similar setup welded in my OLD FC, and it ripped the sheet metal right off the subframe where the brace was welded in. I launched the shit outta the car one night trying to impress an old girlfriend and BANG....
What materials did you use? Launching on slicks with a prepped track, will surely be more of a load, than launching on the street.
Mine is still intact, on the car I sold, and has been daily driven. It was also taken to Road America, Autobahn Park, and Blackhawk Farms, for track day sessions..........no sign of failure, or fatigue.
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It was made out of crap materials and crap welds. I estimate the wheel hop/pinion bouncing ripped it more then a launch on stickys on the track. I bought the entire sub-frame with an S4 diff attached to it so I just bolted the entire thing in since it seemed like a good design at the time. It actually made the wheel hop die down quite a bit, but I think the better way to mount it would be a bolt through design with some inserts to strengthen the attachment point on the rear sub frame. Similar to the way hinson uses inserts on his FC pedestal mounts. That way you wouldn't risk tearing the sheet metal off.
I think your design is definitely the right direction to go for the FC pinion mount, but I was just letting you know about the experience I had with welding directly to the sheet metal on the subframe.
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It was made out of crap materials and crap welds. I estimate the wheel hop/pinion bouncing ripped it more then a launch on stickys on the track. I bought the entire sub-frame with an S4 diff attached to it so I just bolted the entire thing in since it seemed like a good design at the time. It actually made the wheel hop die down quite a bit, but I think the better way to mount it would be a bolt through design with some inserts to strengthen the attachment point on the rear sub frame. Similar to the way hinson uses inserts on his FC pedestal mounts. That way you wouldn't risk tearing the sheet metal off.
I think your design is definitely the right direction to go for the FC pinion mount, but I was just letting you know about the experience I had with welding directly to the sheet metal on the subframe.
There are a few reasons that can cause the lower / horizontal bar to tear away from the crossmember.
- If the bar is too short, and does not reach back far enough, to provide the leverage that is required to keep it from "teeter - tottering", on the front edge of the crossmember
- If the bar is not welded all the way around, including the front and rear edges. It can cause a stress riser, which could easily start a tear at that point
- If the weld was undercut into the stamped metal, causing it to be thinner at that point
- if you had the above things going on, and your original pinion mount was doing little to nothing, to hold the front secure.
3fingerwilly ran one that was nowhere near as beefy as this one, and never had any issues. Granted, he has an automatic, and minimal wheel hop.
There you have it, a few different executions of the same idea. Some functioned correctly, while another failed.
We have had endless threads on controlling FC wheel hop.
One of the best solutions, if not the best, is the AWR lateral rods ( not sure what they are called in the Mazda manual) that AndrewB was running on his car.
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FWIW, my diff is braced similarly (though I have a Dana 36 and the brace on mine runs backward instead of forward). Instead of using a slightly larger hole to allow for movement I installed a poly bushing and mounted it tightly, so just the deflection of the bushing allows movement. It mostly just keeps some noise isolation.
My testing has shown that tightening up the rear diff mount movement helps a TON in controlling the overall diff movement.
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FWIW, my diff is braced similarly (though I have a Dana 36 and the brace on mine runs backward instead of forward). Instead of using a slightly larger hole to allow for movement I installed a poly bushing and mounted it tightly, so just the deflection of the bushing allows movement. It mostly just keeps some noise isolation.
My testing has shown that tightening up the rear diff mount movement helps a TON in controlling the overall diff movement.
I wanted a solid positive stop when under extreme load, but the stock set-up, when driving normal, this does that.
When running several stock "rubber" pinion mounts vs the welded one, there seemed to be little to no difference in vibration etc.
So I just left the welded one in place
Off topic.....Have you run your car with the new converter? Never saw any updates on that.
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If I run into problems I'll prob do something like this -looks good.
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Off topic.....Have you run your car with the new converter? Never saw any updates on that.
I've been knee deep in other people's cars the past few months, so unfortunately, no. I quite literally got it running and the exhaust redesigned to get around the tranny (and about 7" more ground clearance vs. my old setup) yesterday. I'm working on a V6 (4.3/700r4) setup for Indyparts right now, once that's done, I'm switching the cooling system to AN fittings, since Zac's cooling line failure concerns me. It should be out and making some runs this spring. Thanks again to all involved in the converter. :)
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Great write up, post.
Jim
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Don,
Thanks for posting this. Update us on how it feels.
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I built mine from 1x.25 in flat iron from the hardware store. Yes my auto trans wont abuse the pinion near as bad as the T56, however. I built this when I had my NA rear in without the poly bushings and 929 axles. The first month my swap was done I blew the pinion mount. All because of wheel hop. You can use light steel the way Ray has with this style so long as you use it correctly. If you look a little closer at the picture, you will see that my brace is built somewhat like a truss. There are 2 mount points, one is simular to Rays way, but I have a brace that connects to the middle part of the crossmember so it stiffens the bottom brace. in my case I used the OEM pinion mount holes and a 8MM bolt to hold it together.
Beefier is ALWAYS better tho. I was really concerned about weight! :-P HaHa! :D
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WOOT! It works!
Got everything back together late last night. Couldn't test drive it until today. (Way too loud exhaust for the neighborhood)
Went home today for lunch and decided to take the RX7 back to work.
Stopped on a secluded country road on the way back to work and proceeded to do a nice drag launch. Wow! It hooked quickly. barely any noticeable wheel hop and it kept pulling hard through the gears. No squat between shifts. Very smooth power transfer. There is a slight whine from the pinion shaft but it's very negligible. If I were to put a bushing in the place of the 3/8" bolt that would probably go away.
The tranny even seems smoother. Probably because the drive shaft isn't moving up and down like before.
While driving It's much quieter and smoother. The problems I was experiencing before was the extreme pinion angle causing vibration and noise.
I replaced the whole diff cradle as well. I installed an S5 convertible cradle which has a beefier pinion mount anyhow. I Pretty much used stock parts with the exception of some Energy Suspension bushings in the sway bar and end links.
The camber alignment is very close. I measured from the cradle front mount pins to the lateral link bolt (like it shows in the manual) and it was only off by about an 1/8". I tweaked it a little to line it up. I'll still take it in for an alignment though. I'm just waiting until I replace a bad tie-rod on the passenger side of the steering rack which I'll do when I change out the steering rack brace. (the aftermarket one I put in when I rebuilt the car last winter)
All in all it feels very good. Well worth the effort. Especially the price. practically nil if you have the tools.
I would even recommend doing this with an NA Open Diff as well.
Is there better options? Maybe, but I went this route especially after driving Ray's car with this setup. He put over 40,000 miles on his swap with a lot of drag racing. It's very simple but strong. With the way we welded the pieces there is no way they're coming loose. The cradle would have to literally split in half before the welds break. My car is only about 300 RWHP so I believe I'm good to go.
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Glad to hear it's doing well, Don.
I can't believe you'd have any trouble with that setup. Let us know how you like it over time.
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Went to Great Lakes Dragway today to test the pinion brace.
Wasn't my best 1/4 mile but it was my best 60ft on street tires. I give that to the pinion brace.
Had 2 comments from guys in the stands that the car didn't squat and it shot out like a rocket.
I might have had much better times but a kid sprayed his tranny all over the track and proceeded to drive across the lanes to make sure he destroyed both sides. They tried to reprep the track but it was still slippery. Oh well.
[smg id=2421]
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Good Info Don and Ray.
I will do that mod the minute I tear my front diff mount.
How long did your diff mount last before breaking?
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Good Info Don and Ray.
I will do that mod the minute I tear my front diff mount.
How long did your diff mount last before breaking?
About 7 hard launches.
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A traction bar for the FC, woohoo. If you would add a truss under it and extend it 3 or 4 feet farther forward you would have a ladder bar like we used to run on our old shoebox Chevys.
Don, what springs do you have in the back? Jeeeze, get some tires!
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A traction bar for the FC, woohoo. If you would add a truss under it and extend it 3 or 4 feet farther forward you would have a ladder bar like we used to run on our old shoebox Chevys.
Don, what springs do you have in the back? Jeeeze, get some tires!
You said it before I did........Ask Santa for some real traction, and get the job done!
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Okay Don, between myself and Ray we are going to help you. Get some big ass M/Ts, let 'em down to around 9lbs, put, oh say, 5000 rpms ( I know you can go over 7 ) on it and sidestep the clutch. Then immediately grab second and go from there. Right foot flat on the floor for the shift.
I guarantee that will work, that's the way I launched my old Plymouth. If it doesn't, you will need to install the Ford diff that you've been dreaming about anyway.
Happy Turkey Day everyone!
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Hey Jim,
Just don't have the cash flow for wheels and slicks right now. Maybe next year.
I'll finesse my times on street tires then when I do get slicks I'll be perfect. LOL
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Hey Jim,
Just don't have the cash flow for wheels and slicks right now. Maybe next year.
I'll finesse my times on street tires then when I do get slicks I'll be perfect. LOL
So you like the new brace huh? :P
It worked pretty good on my auto trans as well, tho I still had some wheel hop til i went with the 929 axles, poly bushings throughout and later new struts, after that I was pretty good. I'd still get a slight tire shake on drag radials once and a while but not much and not for very long. However the 8.8 solved that and everything else combined to make mine so stable I have zero fear of spinning til my heart is content lol! :D
Add some traction and I'm going down the track now lol. Cant wait to see what the Z06 cam will do this spring lol! :P
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Yea Bill the brace works great.
With the MMR bushings and my springs and shocks it launches great.
When I was going through the water box they spun great. I try not to spin on launch but the track was pretty slippery from a previously blown transmission from another car.
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Yea Bill the brace works great.
With the MMR bushings and my springs and shocks it launches great.
When I was going through the water box they spun great. I try not to spin on launch but the track was pretty slippery from a previously blown transmission from another car.
Well then some good tire should put you closer to 1.5 60's and a little better 1/4 mile. Now you know what to ask Mama for for christmas! :D
Don will be happy then! :D
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^^^ :D
I gotta sell the 17x18 ATS (Mustang) rims with tires I have on craigslist and then I can buy some slicks.
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Good luck with the sale, Don. What do you have in mind for the back?
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Good luck with the sale, Don. What do you have in mind for the back?
I'm not sure. I'll probably just get some 15" steelies with MT drag radials.
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I ran Ray's 16x9.5 Hoosiers one night at the street drags and had NO traction issues at all. Did'nt seem to matter about the tire pressure though my car is stock(ls1). They were on 16x 6.5 acura rims too. If you have to spend money on tires, I say at your power level go with a set of those. DR's will probably leave you somewhat disapointed especially if you plan on more power later in the game. I know mickey's are better then Nitto's, but launch is where you make the most time up so slicks is a no brainer here.
:D
Thats where I'm going next lol! :D
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Every car reacts differently. Ray has cut 1.7's on the QTPs, my best on those tires is a 1.89 with most runs 1.9+. My best on 245 Nitto dr's is 1.85, 1.86, 1.88 on a very well prepped track. Most of my times on the Nitto's is 1.9+.
Power level??? I can run 12.2's at 113+ but sure as hell can't get a good 60'.
So...borrow a set from someone and see how you like them whether it is slicks or dr's.
The 16x9.5 QTP's are a little taller and did help my mph by 1 or 2 mph.
Keep in mind that the Nitto dr's can be run on the street and I've been doing that for a couple of years. They sure as hell beat the BFG's I had before.
As a disclaimer, my car has transmission and driver issues so all that I've said doesn't amount to sh*t anyway.
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congrats on your results. get some good tires on there and watch what happens
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Jim...........I was cutting consistant 1.63's & 1.64's not 1.70's :D
More tire, would have shown better results, but the QTP's worked well for the size that they were.
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I definately need to do this to my car, the mount has broke twice now. Hopefully this will solve my problem, I just need to get another rearend first! =(
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(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_190800.jpg)
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_190736.jpg)
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_153356.jpg)
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_160218.jpg)
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I used stock s4 sway bar links, I have 3 more pm me if you need to buy one
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Let us know how the link holds up. I might switch mine over to that link if they don't break.
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Should hold fine...
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Do this, and forget about ever ripping the mount off of the crossmember.
All the other mods to firm things up, only make it better.
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Supp guys so I'm about to do this to my rx7 with a 5.0 swap I just need to know the width of the plates used thanks
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Supp guys so I'm about to do this to my rx7 with a 5.0 swap I just need to know the width of the plates used thanks
Check the first post in this thread. All the info is there.
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If you used an adjustable heim setup, could you use this to set your pinion angle?
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If you used an adjustable heim setup, could you use this to set your pinion angle?
You will only get a slight amount of downward movement since the stock pinion mount has as a small snubber to keep the pinion off of the subframe. if you cut that off, then I suppose you could get it to move the pinion down but there will be a constant upward load againt this brace. I think it would want to tear the plates off of the subframe, or break something somewhere.
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so basically you would be making the rubber mount "harder" by eliminating movement.
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Effectively making it solid. Same as welding a plate across the rubber, which has been known to crack subframes. You wouldnt get the movement that Ray designed into his limiter because (assumingly) you would already have the pinion loaded upwards or downwards to obtain your desired pinion angle.
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If you look at the pictures of what I did in the first post you will see that I boxed the pinion mount so there is no movement.
If pinion angle adjustability was wanted a heim joint configuration could be used instead of the bar stock I used. But, I'm thinking you're going to need a pretty beefy heim joint to withstand the forces put on it.
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This is all it says
5/16" flat stock cut 7" each
Whats the thickness and what's the length and width ? If you can help me I would really appreciate it.
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Looks like 1" wide to me.
5/16" would be the thickness, and 7" would be the length, just like it says (and you quoted)
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Blake beat me to it. I was going to say 1 1/2 wide since a 1/2 bolt head is 3/4" wide
DD
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Thanks a lot. I will post some results of this mod once I do it
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(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_190800.jpg)
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_190736.jpg)
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_153356.jpg)
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_160218.jpg)
this seems to be holding up fine. Have did a few autox's on it, a few road trips and now my t56 is in. So I can really bang on it now. :drive:
Thanks,
Bret
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just posting up how mine ended up.
used a lower profile bar than atli126, but reached it further back on the subframe.
(http://i113.photobucket.com/albums/n229/greencactus3/CAM00149_zps55d46a62.jpg)
(http://i113.photobucket.com/albums/n229/greencactus3/CAM00148_zps7f509444.jpg)
i paint everything white so i can find cracks easier.
one thing i thought about is the direction of the bolt in the upper hole.
if for whatever reason the bolt backs off, my bolt wont interfere with the dshaft/pinion.
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So I wanted to come back and update that my front diff mount ripped on me. I never did the pinion snubber bushing up top, so do you think that is why the front mount ripped. I also didn't box weld the competition mount. I still have the sway bar dog bone in place so I'm kinda confused as to why it ripped
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But I also pulled out the delrin wing bushings last year or 2 years ago for the mazdaspeed 30% stiffer bushings and less nvh over 40 mph but immediately after I did that I had pretty aggressive wheel hop issues. I know wheel hop tends to break stuff. But this time I'm going to definitely put the pinion snubber in there and get a new competition front mount prob from racing beat
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So I wanted to come back and update that my front diff mount ripped on me. I never did the pinion snubber bushing up top, so do you think that is why the front mount ripped. I also didn't box weld the competition mount. I still have the sway bar dog bone in place so I'm kinda confused as to why it ripped
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If you didn't box the pinion mount then yes that's why it ripped. It stretches like a rubber band under load and can only take so many hits. Those tabs on the mount washer don't offer any protection. (If they're still even on there any longer)
A snubber might have helped a little but that also has a tendency to compress under extreme load. Again, the pinion mount rubber can only take so many hits before it fatigues.
What GC3 did with the bushings on the mount would help with NVH but that link could also break under load after a few hard hits. (You have to understand how much load is applied at that point) His saving grace is ease of replacement when it breaks.
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(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_190800.jpg)
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_190736.jpg)
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_153356.jpg)
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_160218.jpg)
this seems to be holding up fine. Have did a few autox's on it, a few road trips and now my t56 is in. So I can really bang on it now. :drive:
Thanks,
Bret
This is my setup. I used the sway bar link (dog bone) first and now everything but the front diff mount is still good. I have the mazdacomp rear diff bushings (may, 2015) and the front mazdacomp diff mount (2011, when we boxed it)
I'm now trying to figure out if I want to replace the stock rubber subframe bushings with delrin.
I pulled the delrin wing diff bushings bc of terrible nvh and road noise on Highway trips for shows and autox over 20 minutes away. I'm really trying to keep my car a street car (ac, ps, poly bushings, tein flex with edfc, "street" 200 tw re11a ;-) etc)
Also could I run a solid diff mount from pbm
https://store.partsshopmax.com/shop/FC/SolidBushing/FCSDB.html
with the delrin subframe bushings? Or is that going to be too extreme?
http://pages.ebay.com/motors/link/?nav=item.view&id=111814656780&alt=web
Or should I stick with the mazdascomp front mount from racing beat and do the pinion snubber and keep the rubber subframe bushings?
Can the Mazdacomp front mount be reinforced at all with welding on it? Is that what some have did? If so does that push back to the full Metal front mount for less and no rubber (but with full Metal it Could rip the subframe right?)
Ugh I'm stuck and need to order new parts and stuff today
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Unfortunately I can't offer too much more advise on what you should use.
I've since converted to a Ronin 8.8 conversion.
I will say that I am using the Mazda Comp diff bushings over the Delrin and have not noticed any wheel hop and NVH is very minimal to almost none existent except for a slight whine at about 70mph. (Not obtrusive at all)
The Ronin setup uses a pretty solid pinion mount but I'm using the Ford Explorer stock rubber bushing.
(https://www.norotors.com/gallery/albums/Ronin_8_8_Swap/Dir_1/medium_7285.jpg) (https://www.norotors.com/index.php?action=gallery;sa=view;id=7285)
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with my setup (poly bushings in the dogbone, mazdacomp rubber front mount, solid uhmw rear mounts) running 275 NT01s I never got wheel hop. With the stock lm7 I was running I doubt I could break the endlink.
As for NVH, I had lots of it, but no idea how much was due to the way the diff was mounted. everything was loud and noisy and obnoxious.
I never ran a snubber bushing above
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You CANNOT run a solid front diff mount with rubber subframe bushings. You will rip the mounting tabs off the subframe.if you want to keep it a street car, replace your mazdacomp front mount.
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with my setup (poly bushings in the dogbone, mazdacomp rubber front mount, solid uhmw rear mounts) running 275 NT01s I never got wheel hop. With the stock lm7 I was running I doubt I could break the endlink.
As for NVH, I had lots of it, but no idea how much was due to the way the diff was mounted. everything was loud and noisy and obnoxious.
I never ran a snubber bushing above
Thanks for the reply the nvh is mainly attributed to the delrin rear diff bushings. Once I swapped them out with the mazdaspeed rear diff bushings. The nvh over 40 mph went away and overall the whole car is way better.
But that was last year and that's when the wheel hop came on like crazy and prob broke the front mount.
With my setup could I run the delrin subframe bushings and the solid front mount?
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So I found this product but apparently it's a major major major bitch to install but won't break. I'm trying to order one but lucky 10 http://www.lucky-10.com/ is saying they don't have any in stock. But this seems like a great legit option if it won't break or rip the subframe tabs (not supposed to)
(http://uploads.tapatalk-cdn.com/20160411/b23bf3031f74d4f49ceeddbcade53bd3.jpg)
(http://uploads.tapatalk-cdn.com/20160411/804daef80989239183cda251a33b20f4.jpg)
(http://uploads.tapatalk-cdn.com/20160411/b7f1303bca23bb2b4833c0a5f799b025.jpg)
(http://uploads.tapatalk-cdn.com/20160411/87688e4e8488587cba29e5c0dcb75073.jpg)
(http://uploads.tapatalk-cdn.com/20160411/0fe76728c73ad6b2670cd2b679dfd3f1.jpg)
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http://www.lucky-10.com/parts.html
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I guess I don't see why it would not break the tab off the subframe unless the compliance from the delrin? bushings somehow prevent it from happening. In any case - whatever gets stronger creates the next most likely weakest link which IMO is the tab on the subframe.
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I would not run the solid subframe and front diff mount with rubber rear bushings. It will ha e a better chance of living..
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So unless I hear from lucky 10 about getting that nice mount with the poly, I'll just go with the standard mazdaspeed competition front mount, have it box welded and keep the rubber subframe bushings and just install a pinion snubber bump stop this time around. The last mazdaspeed front differential competition mount did last 5 years...
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Was your old diff mount boxed in (i'm assuming not). If you are box welding it it together, just get the PBM solid front diff mount. That Lucky 10 thing is effectively solid anyway.
If you go solid in front you need solid subframe bushings or you will break the subframe next time.
If you like the way it was from an NVH perspective, buy 2 mazdacomps, one to replace the broken one and one to have on hand as a spare. Preload the front of the diff with a snubber and it will be fine for a long long time.
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I'm going to do the latter just get the Mazda comp one, snubber, and I bought the poly bushings for the dog bone too
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http://www.rx7club.com/group-buy-product-dev-fc-rx-7-268/front-diff-mount-prototype-997329/ (http://www.rx7club.com/group-buy-product-dev-fc-rx-7-268/front-diff-mount-prototype-997329/)
here is another option but still cant buy
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Soooo I still have the car apart and am waiting on parts, I finally bought the lucky 10 front (with semi-solid UHMW plastic (Ultra High Molecular Weight) bushings and I also have the mazdaspeed oem front mount (might end up selling that one)
but now am debating on going with these delrin subframe bushings
http://www.ebay.com/itm/111814656780?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/111814656780?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT)
to try to help it. From what ive read and those I've spoken with it seems like the delrin in the subframe wont transmit that much nvh into the car but help hold it all together better. I got 3/16's steel plate that we will be welding in and gusseting to make the subframe tabs stronger. I'm hoping that will help keep it all together.
What do you know about the delrin in the subframe? Does it make it harder to install the rear subframe back in?
Here is my setup;
Ronin level 2 rear camber links, stock mazda link (useless with delrin subframe mounts right?) dtss in the rear arms, poly bushings, and the mazdaspeed diff bushings with a t2 s4 turbo diff.
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Yes go with delrin subframe bushings.
That diff mount is basically solid, but it should reduce some noise.
Install is as follows:
Install diff and subframe as a unit.
Bolt front diff mount to diff and torque to spec.
Bolt subframe to diff loosely, just so they don't fall apart.
Raise assembly onto the car and when the subframe and diff are both on the mounting studs, go in with a ratchet with an extension and tighten the front diff mount to the subframe.
Raise it the rest of the way and torque subframe and rear diff bolts to spec.
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Any chance I could leave the diff in the car. It's up on a lift now and we took it apart without pulling the diff. But that was with the broken Subframe tabs so that might have helped...
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Any chance I could leave the diff in the car. It's up on a lift now and we took it apart without pulling the diff. But that was with the broken Subframe tabs so that might have helped...
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Broken subframe tab helped a lot.
Yea.. you'll want to lower it on the rear mounts as low as you can and support the front.
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Ok thanks i really just don't want to pull axles etc
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Ok thanks i really just don't want to pull axles etc
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What did you do to get it out? lower the subframe and pull the trailing arm bolts, camber dogbones and sublink? Are the trailing arms still hanging from the shocks in the car?
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Yup, prob not the best idea u
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With the stock diff it is really easy to pull the arms off the car, just unbolt the halfshaft from the diff output shaft, leave the output shafts in the diff.
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So got it all installed and back together!
Used the delrin subframe bushings and the lucky 10 front diff mount with red poly shock bushings instead of the hard mwmh bushings that came with it.
So far so good. Got it up to 50 mph on the way home and no crazy sounds. Will hopefully drive it to work and get up to highway speeds and hopefully it's still quiet. Remember I put a huge emphasis on "street car"
Enjoy ☺️
(http://uploads.tapatalk-cdn.com/20160508/252a19829b8b2bc0380974c4dc789a5b.jpg)
(http://uploads.tapatalk-cdn.com/20160508/1b39c15e5eea5930398fd6dfc4832761.jpg)
(http://uploads.tapatalk-cdn.com/20160508/de0188c7744f68884ba596b1c123ff7d.jpg)
(http://uploads.tapatalk-cdn.com/20160508/ec4afd4f1e129fe195108350f11e20d2.jpg)
(http://uploads.tapatalk-cdn.com/20160508/cd5b36c8bdca37935d8904eb48b5edab.jpg)
(http://uploads.tapatalk-cdn.com/20160508/a401019eff0b00a0c42fbb9185b16dbf.jpg)
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Ahh so it comes with 2 sets of bushings? If it still moves too much put a UHMW bushing in the middle of the 2 poly ones.
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Ahh so it comes with 2 sets of bushings? If it still moves too much put a UHMW bushing in the middle of the 2 poly ones.
nope. I removed the white mwmh bushings and bought a energy suspension red bushing tie rod link setup from autozone with 3/8's holes and used these. I only had to barly grind the little top nipple off of them. :cheers:
now the car rear feels solid with the upper bumpstop, lucky 10 front mount and the new level zero motorsports delrin rear subframe. No crazy NVH at 80 mph this am either
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I was gonna say, those look like end link bushings.
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Oh yea we also cut out the broken tabs and welded in a thick piece of 3/8 steel and welded the tab on top too, to hold it all back into place. Im sure its a combo of all three but Im happy and hoping that this helps me have a legit good solid rear "street car" option.
The Differential Pinion Brace w dogbone mod was great but i think it just made the front mount and tabs the next target. Hopefully now itll hold up over time :)
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Ok I'm back with some pretty hard-core clunking issues. That lucky 10 mount used wheel studs into aluminum and I think the nurls (small teeth) wallered out the alum. I could never get the lug nuts tight enough to hold it down under the subframe tabs.
So tonight I pulled the mount back out. We are going to buy some steel and rebuild the C Part with steel that way I can get new studs and weld them to the new C part of the bracket...
I'm half tempted to go with the white delrin bushings this time. The new box on the subframe and tabs are find and holding but I also think I might have ground down the 2 bolt washer (oem) that holds down the mount under the tabs. I'll probably try to buy a new 2 hole washer or make one out steel that will fit better and not let them move up and down in the channels on the subframe.
I was Half tempted to go with the solid pbm mount... But I still don't think SOLID is the way to go.
I do mainly race and autox the car but I also cruise and travel to and from events.
I feel like I need to just save up and go with the ronin 8.8 to be honest...
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Pic
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Pic of c part of mount
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you could weld a tab connecting the 2 studs into a stud plate so you can get the full torque you need on them.
If you never got them tight it isnt surprising to hear the aluminum opened up even more
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The plan was to remake the c section (shown above) out of steel and tack weld the studs to the back of the plate that way they can't move. But we might look into that too.
I was trying to think about some way to do some sort of attachment that would allow the diff mount to be bolted down north to south thru the subframe. But that would require probably drilling holes in the subframe and some how attaching something to the studs (maybe an L bracket) and then bolting them down to the subframe so it can't raise up...
Thinking like a 2 hole washer but it is an L bracket that I could use to bolt thru the subframe... Maybe that's crazy. I just woke up. [emoji23]
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Another question I still have the stock camber rod. If I upgrade that will that help with the subframe movement?
I only ever thought of that as a camber adjuster but I'd say my stock rubber are probably wore out.
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I was trying to think about some way to do some sort of attachment that would allow the diff mount to be bolted down north to south thru the subframe. But that would require probably drilling holes in the subframe and some how attaching something to the studs (maybe an L bracket) and then bolting them down to the subframe so it can't raise up...
Had a similar idea way back when before I discovered this thread. You could run some beefy bolts all the way through the subframe, and bolt to an equally beefy L-piece on the stock diff mount location, but the subframe sheet metal isn't that thick, so you'd want to have some kind of saddle plates to spread the load out. In the end it really isn't any different than the front pinion brace this thread started with, though I guess there would be less of a leverage problem.
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So my plan is to go buy the raw steel today to make the C part of the lucky10 mount in steel, weld the wheel studs to the steel, use the white delrin bushings and go that direction .
but...
It seems like I have 2 options, now that I have reinforced the tabs and rebuilt the box on the subframe, delrin subframe bushings, and pinion snubber..
I could just install the NEW mazdaspeed mount I still have and run this setup again. I also have poly bushings I can install into the dog bone.
What would you do?
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_190800.jpg)
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_190736.jpg)
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_153356.jpg)
(http://i345.photobucket.com/albums/p386/atli126/IMG_20111203_160218.jpg)
this seems to be holding up fine. Have did a few autox's on it, a few road trips and now my t56 is in. So I can really bang on it now. :drive:
Thanks,
Bret
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The stock sublink rod does have rubber in it. A solid aftermarket one will yield less subframe movement.
IF you have a Mazdaspeed mount, run it and put the pinion brace back on to limit movement.
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Got the poly installed into the s4 rear sway bar link tonight.
Hoping it all goes back together and plays nice tomorrow but I'm sure it'll be a bitch. Ol Betty white is always a bitch to work on...
(https://uploads.tapatalk-cdn.com/20180126/4df9c4e61fbfc01e41bf65660b2bb1aa.jpg)(https://uploads.tapatalk-cdn.com/20180126/8a6043b3f25cdc8b6eb0fe370d52133c.jpg)
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So it was pretty tough but we got it back together. Went back to the mazdaspeed diff mount vs the lucky10 custom mount setup.
I know it might not look like the 2 nuts are on there enough but when we remade the new box and tabs we used 3/8 steel and almost made it too thick. So thats the best we could do but it's a very thick wheel nut or trailer nut, it's only about w threads off from being fully threaded. We also put the gooey red lock tite on it. So I think it'll hold.
Just gotta go back to my buddy's tomorrow and put the exhaust on and drive it home!
So now it has Mazdaspeed front and rear diff bushings, 3/8s steel box and tab, delrin subframe bushings, ronin stg2 camber dog bone, pinion snubber and the s4 sway bar link with poly bushings (https://uploads.tapatalk-cdn.com/20180130/80913921ff869ec1895e70d7e90e6b31.jpg)(https://uploads.tapatalk-cdn.com/20180130/f2592ad09c12fedda0b92f3e81324076.jpg)
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Fc is solid... For now hah! drove it around and home tonight and it's pretty legit. Hopefully this setup will stay clunk free for a while... At least until maybe I can swing a ronin 8.8 kit like next winter [emoji14]
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You CANNOT run a solid front diff mount with rubber subframe bushings. You will rip the mounting tabs off the subframe.if you want to keep it a street car, replace your mazdacomp front mount.
hey i have a solid diff mount, with rubber subframe bushings. the diff mount bracket on the subframe ripped off. are you saying i need poly subframe bushings? or solid? so that the front diff bracket wont rip off?
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I'can't keep this setup living on mine. I've tried reinforcing the madzacomp mount, the mount welded off the bottom of the cradle, have a pinion snubber, I've got poly cradle mount with aluminum plate retainers holding the diff to the body etc. But the torque of the link bar bends both the rubber mount and the link bar mounts.
Has anyone seen a design that surrounds the front of the diff and has a link on the centerline of the diff so the force excerted is straight down?
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Nope I think it's a temp fix until the Mazda comp breaks and you have to replace it. The first one I had lasted a few seasons and years of racing. But I think the best option is the ronin 8.8 setup
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I have no doubt the Ronin setup would be a good fix but $2k makes one look for other options.