Originally Posted by itty bitty
I am mechanically inclined. Done engine swaps and things like that. But never any pumpkin work or axle stuff.. I have 31" tires on it. And I can't seem to figure out exactly where the noise is coming from. Pumpkin or axle.... I'm gona change fluid first, seeing as I just got the vehicle and who knows last time it was done and if its been "swimming" ill inspect while cover is off... But that's the problem. Not sure what I'm looking at, or what to look for. Aside from the obvious sparkle of metal in fluid or chunks..
Before you remove the diff cover, raise at least the rear end off the ground and set it up where you can run it in gear off the ground. Make sure it is stable!
Put it in gear and then crawl under with a stethoscope. Listen to the various bearings (pinion, both axle brgs, carrier brgs, and transfer case. You may hear the difference in one or more that will tell you better where the noise is coming from.
If it is gear noise, it may not show up this way because it is free wheeling with no load, but that is OK. Check for leaks on the axle too. That may tell you something.
You might want to look at the brakes just to be sure that's not what you're hearing as well.
Once you pull the diff cover, look for flakes in the oil and chunks in the bottom. If something is truly going bad, you will find some metal of some kind.
You'll need a manual that shows the proper wear patterns on the ring and pinion. Check yours against the manual to see if it is running OK. Check the back lash if all that looks good just for a reference too.
You might want to be very suspect of your U-joints too. Check them for any kind of movement.
If you have a friend with gear experience, get them to come over while all this is going on.