Well, I am day 7 in the gear reduction project for the TJ.
I have the rear complete with the Detroit True-trac and am working on the front end.
The front end was going a little more difficult with some rust issues (Jeep spent most of its life in Pennsylvania) and had alot of trouble finding enough torque to remove some bolts but slowly but surely it came apart. As for the front end, I actually bought the the front end built with 4.56 gears in the housing, etc. on craigslist for like $200 bucks and finally got it finished up building and installed.
So this morning, I filled er up with 80W-90 and took a test drive. First in 2x4 around the block...everything o.k.
Kicked er in 4x4 hi and in about 100 yards, clank and the front diff locked up...
At this time, I have spent a lot of hours on this project and I have my elk hunt starting sat. I paid a tow truck to tow the Jeep to the shop and he suspects that I over-tightened the pinion nut and crushed the bearing...I hope he is right and hope the gears aren't whack..
I'll keep you posted...