beertestr
Club Member
I am trying to get the pattern right on my 8.6" 10-bolt. It's a 8.5" housing, with a newer 8.6" 3.73 R&P and Newer Eaton Gov-lock. I am using a setup kit from DTS that has the correct bearings to get this newer diff into the old housing (bigger ID on the Diff bearings).
I keep messing with pinion depth and backlash, and keep chasing the pattern. Currently, I have ~0.060" worth of shims under the pinion bearing, and no inner shims on the left side. Backlash is at 0.008". Reading the info on Dana's website (also copied onto the Drivetrain.com website) it says I need more pinion shim, i.e. the drive side is toward the heel, and coast side is toward the toe, but right in the middle root to tip. I added more pinion shim, about 0.040" (0.080" total) and it was too tight, I couldn't take out enough shims from the left side to even get it turning smoothly. FWIW, the shim kit that DTS includes has an outer and inner shim, so that you can put thinner shims in between them to fine tune the setup.
I'm thinking that if I go from the current 0.060 to even 0.070", I will end up too tight on backlash to even get started.
Am I on the right track, or am I missing something very fundamental?
For the record, it's been lovely messing with it in the driveway with passing t-storms.
I keep messing with pinion depth and backlash, and keep chasing the pattern. Currently, I have ~0.060" worth of shims under the pinion bearing, and no inner shims on the left side. Backlash is at 0.008". Reading the info on Dana's website (also copied onto the Drivetrain.com website) it says I need more pinion shim, i.e. the drive side is toward the heel, and coast side is toward the toe, but right in the middle root to tip. I added more pinion shim, about 0.040" (0.080" total) and it was too tight, I couldn't take out enough shims from the left side to even get it turning smoothly. FWIW, the shim kit that DTS includes has an outer and inner shim, so that you can put thinner shims in between them to fine tune the setup.
I'm thinking that if I go from the current 0.060 to even 0.070", I will end up too tight on backlash to even get started.
Am I on the right track, or am I missing something very fundamental?
For the record, it's been lovely messing with it in the driveway with passing t-storms.