I got the car back together this weekend. It took me a dozen tries to get the preload with the solid pinion spacer correct. I don't have the correct pinion wrench tool, so I was using the biggest pair of Channel-locks to hold the yoke while using a torque wrench with the other hand. Giant PITA. Everything is back together now and I put some trouble-free miles on the car over the weekend.
The diff is mostly as quiet as before I think. MUCH quieter than when the crush sleeve was toast. Below is a photo of the Ratech crush sleeve new and used. It had permanent deformed 0.050" and there was NO preload on the pinion and even a slight amount of end play.
I also replaced one of the leaky scavenger check valves that was coked up with burnt oil. I also bought a second oil cap, drilled and tapped it for 1/8" NPT, and plumbed it to a 2-bar MAP sensor that's logged through the ECU. The scavengers pull 0.5psi of vacuum at idle, a little more during cruising, but crank case pressure climbs during pulls. It seems to creep higher the longer the pull, which makes me think the the breathers just aren't flowing enough. It makes around 1psi crankcase pressure at 6500rpm and 10psi after a 4000rpm-long pull. Good news is, the car isn't leaking or burning oil anymore. No clue what pressure was before I replaced the valve, but it had pushed the front seal out twice and was dripping a good amount of oil. I just pressed the seal back with a prybar and crossed my fingers it'd stay put. Pulling the balancer would require removing the radiator and I was hoping not to have to do that for now.
When the diff was apart, I reinstalled the Ford reluctor wheel to the diff in the hopes of getting a clean rear VSS for traction control (DCT controller's VSS is super noisy). I wired the Ford 2-wire sensor to the ECU as a VR type sensor, but haven't been able to get it to work. My plan is to replace it with a Hall sensor.
I did add a
ton of smoothing for the noisy DCT VSS and got it to mostly track the front wheels. The issue is, when there's a huge spike up or down from noise, the smoother VSS will make a small shift for a longer duration, which throws the car into TC. The MaxxECU traction control is pretty interesting. There are no correction maps for %cut or retard vs. wheel slip. It just has a PID table (a single table or a PID for high speed and low speed) and you select what method you want to use for TC (spark cut, cut and retard, fuel cut, etc). With the default setting and noisy VSS, it was still able to reign in wheel spin in 2nd gear, which usually just smokes the tires. I'm looking forward to getting the rear VSS working properly.
