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duxthe1 · #8 06-17-2019, 08:43 PM

After about 600 miles I've pulled the diff back out. There was a slight hissing sound coming from the left side bearing. Couldn't hear it in the car but with the windows down, driving past a fence or like, I could hear a noise reflected that didn't sit well. Running it up to speed on the lift it was clear the noise was mainly the left side bearing and maybe a little on the right.

So today I swapped it back out for the 3.27 while I get the LSD sorted..... again.

So upon disassembly it looks like the preload was too tight on the side bearings. Upon inspection you can see fine scoring of the race with pitting just starting. Damn! I consistently measured 0.19 to 0.20 mm for case spread and the spec is 0.10 to 0.20 mm. I figured that the tight side of the spec would be ok. I figured wrong. My next move here is to go 0.05mm thicker on both side shims to put the case spread on the low end of the spec while keeping the backlash where its at.

I would have set it a little looser if I had shims in the range needed to do it. My selection stepped from 1.65 to 1.8mm At this point it looks like I'll have to get a thicker shim and have it ground to 1.7mm. The right side shim will have to go from 1.05 to 1.1, which I recall was available in my selection. This is assuming that the replacement bearings install to the same dimensions these last ones did. One odd thing I noted was that the wear path between the left and right sides were in different spots in the races. Given that, I'm gonna have to check and re-check everything again on the next assembly. Nothing will be assumed. I'm specifically not looking for a charming 3rd try.