Hi All
Just rebuilt and installed my first 8 3/4. On the test/ break in drive, I noticed a few things.
Here is what I am working with
-489 case
-3.55 gears from Yukon (rebuild kit from them as well)
-Eaton Tru Trac
-Ratech crush sleeve eliminator
1. Under ~60 MPH the gears were quiet (car is noisy but I didn't notice any unusual gear noise. Over this speed and with the car in gear I noticed a humming noise (Felt more like harmonics than anything). If I put the car in neutral to coast it got quiet again
2. On my return trip, I started to notice a lot of gear whine when coasting to a stop.
When I set this up, I had a tough time getting the pinion preload set. At first, I could hit preload with only 90Ft lbs of torque on the pinion nut. A thinner shim would all but lock the pinion up at the same torque. I ended up filing an honing down the pinion spacer and was able to get 175 ft/lbs of torque on the pinion nut w/ the correct preload. I left it at this with some blue Loctite. Looking back, I was losing patience with constantly reinstalling the pinion to get this set... All that said, I feel like I screwed up on the preload (nut loosened up or the bearing cups settled). So, am I thinking correctly, is there anything else I should look at once I have a chance to pull the 3rd member out?
Just for reference, here is my contact pattern after final assembly.
View attachment 1715165667
View attachment 1715165668
