I have run across an unusual problem while re-gearing my '88 YJ's rear end. I'm putting in a set of used 3.55s to replace the 3.07s that were in there for a 180,000 miles to better suit the 31" tires. The front end went as advertised with only the usual swearing and and wrench throwing. Both sets of gears looked to be in great shape. The problem started when I began reassembling the rear(all new bearings and such of course) I first used the same shim set up as it was before. Installed the pinion(with a setup bearing) and then went to put in the carrier and check the backlash - with the same shims it measured about .080! Well, okay, I can fix that right? So I start swapping shims from right side to left and before you know it I'm down to 0 shims on the right and and a whole bunch on the left and the backlash is now at .012. Still too much so I run a pattern and it shows the pinion a bit too far out so I bring it in .015 and check backlash - .060 good but pattern shows too close! I back the pinion out .005 and get a backlash of .008 and a pattern that is not ideal but at least pretty well centered face to flank. Anyway, I don't have anymore room for adjustment on the backlash and if I move the pinion out even a hair my backlash goes out of tolerance! Anybody ever encountered this before? Did I screw something up or is just a crappy set of gears? Any opinions would be greatly appreciated as I need to decide whether to go with this or just...go at it with a sledge! [img]/ubbthreads/images/graemlins/AR15firing.gif[/img]

Attached Images

File Type: jpg

1450270-JeepRearEndDrive.jpg (57.8 KB, 19 views)

Original carrier?

Yep, the only thing I changed were the ring and pinion gears and all the bearings.

Unless I missed something you are now set up within specs?

They are used gears, if I had a decent patern and the backlash was right I say run them.

But I am only an amature at the gear swapping thing so somebody else chime in and tell this guy if I am wrong!!

I'm with Rio...Whst's wrong withwhat youv'e got now? other than you've wasted....sorry spent this muchtime on a d35 already......

I guess I'm just very paranoid about putting this back in with all those shims on the ring side of the carrier...just doesn't seem right. I've been doing some more research(should have done before!) and it appears on the 35 you need a different carrrier when you go higher than a 3.31 gear set. I guess on the Dana 30 the cutoff is anything above 3.55 which is what I remember seeing and just assumed they were the same. I'm thinking this is probably the problem and I need to get a new carrier ASAP(Yukon has one for $58). [img]/ubbthreads/images/graemlins/tongue.gif[/img]

Attached Images

File Type: jpg

1450337-JeepRearEndBearing.jpg (56.6 KB, 12 views)