Help diagnosing diff problem - RC-Monster Forums

JThiessen · **Help diagnosing diff problem -** 05.02.2010, 06:30 PM

Guys, I've been chasing a gremlin in the rear diff on my 8T for a while. A month ago, I tore down the rear end looking for something that would cause my rear diff to lock up. I completely pulled apart the diff, installed new spider gears and bearings, shimmed it, and re-shimmed it. Prior to installing it, everything felt fine/normal. Now after I get it all back together, one side wont turn (RH side when looking at truck from behind). The LH side turns fine in both directions. I can get about half a turn at the wheel on the RH side.
Almost makes me think I might have used the wrong length of screws to mount it or something - but I'm still running the stock screws that came in it.

What's_nitro? · 07:58 PM

Are you sure it's the diff locking up and not the out-drive and/or dogbone? There is still action in the diff when you turn from either side, so I would think it would lock from both sides if it were the diff. Maybe a set screw is loose on a drive cup? I'm not real familiar with the 8's so forgive me if I'm way off.

JThiessen · 05.02.2010, 08:40 PM

No, I'm not cetain. However, I noticed it as I was replacing the inner bearings. The drive cups are held in place with a cross pin, which is retained only via the bearing.

After I first posted, I went back and forced it past where it felt like it was sticking. It didn't take much extra force to get it past that spot. I noticed as I was trying to turn it that the truck was trying to rotate up. So I'm wondering if one of the outdrives coming out of the diff is slightly bent. And that's kind of how it feels as I rotate either of the drives - tight for a spot then loose for the remainder of the rotation.

I first noticed this whole thing last fall AFTER I had sent it off a 15 foot sea wall (onto sand) a couple times. After that, the truck would periodically stall out on me, and the tires were locking up when I let off the throttle.