On our recent 700 mile trip to the desert, I noticed that around 60-65 mph that when I let off the gas, I hear a whine/howl coming from under the jeep and at certain speeds, a faint grinding. Sounds like either the tcase or rear end. The gears are about a year old with less than 5000 miles on them and were set up by a reputable shop (Leonard, for the local guys). Any ideas?

Nathan

Edit: It is an 8.8 rear end with 4.56's and a 231 tcase from an 88 xj

had a 2wd S-15 that I stuck a V8 in do that after I had the rear set up with 5.13's less than one hundred miles on them and the carrier. anyhow pinion nut had came loose on it.

My yj is doing that right now, but it's noticable at all speeds. I just setup the gears, and don't think there is anything wrong with them. I'm betting on the outer pinion bearing (it was used) being bad. When accelerating, the pinion pushes back against the inner bearing, when decelerating/engine braking, it pulls against that outter bearing. If the outer one was bad, that's when it would make the most noise. Loose pinion nut could cause it too. Don't know if that's it or not, but it sounds good.

Chad

Well I took the rear shaft out and snugged on the pinion nut and it didn't seem loose. I don't know what the torque should be but it did not turn. How can I tell if the t case is shot? What could cause the whining? Planetary gears? anyone have a 231 case laying around?:flipoff2:

nathan

Just changed my front pinion bearing, and it fixed it :cool: but I'm not sure if it was the bearing that was messed up (it had some wear, but so did the used one I put in) or if the preload wasn't right. Either way it's working good now. Now I just need a way to set the preload right...

chad

^

Pull the cover on the rear diff, and check to see if there is any play in the carrier.. mine was making that same exact noise, and it wasted the driverside carrier bearing.. caught it in time, and only had to replace the bearings on the carrier

Thanks, I'll give that a try.
nathan