jakeduece

Hey guys, I've been researching this for a week and really haven't found anybody with exactly the same problem as what I have. I have a 96 cherokee, 190,000 miles, with a rear differential noise. Its a 8.25. Lately when I hit around 10-15mph i get a constant humming that increases in pitch and loudness as i increase speed. if I let off the gas the noise stops. as soon as i hit the gas, voila the sound is back. I checked my rear tires to see if they had any movement, they do move up and down VERY little. I also checked the drive shaft for movement and it moves very little in every direction (right by the differential). it moves in and out, up and down, side to side. What could be causing this sound? everything is pretty much oem parts, very old and a little rusty. also the differential fluid is dark brown, and smells. Please help, I have a trip coming up soon!!

Savage71

how did you determine the color of the diff oil? through the plug? or from a leak? if from the plug...was it full? possible pinion bearing or warn gears. my .02. good luck

builtnotbought89'

Sounds like your pinion bearing is bad! Bad news is you'ld have to reset the gears. Good news is 8.25 axles are cheap. I'd just pull it, & swap out with a JY axle!

94cherokeeman

I have a 8.25 axle and it wont lock posi and my buddy has the same one and his locks up why is this

jakeduece

I determined the color by opening the drain plug, and sticking a rolled up piece of paper towel into the hole, makes it easier for me to see the level of the fluid and the color. How much would it cost to swap out an 8.25 from a yj? Also, can I drive the jeep like this or should I avoid driving it until it gets fixed? It's my only car! Thanks for your help everyone!

jakeduece

Oops jy not yj stupid autocorrect lol

builtnotbought89'

It depends on the prices at your local jy & if its a self pull or full service yard! You should be able to find an 8.25 for $150-$200 which is A LOT less then you'll pay to regear!

jakeduece

Ok I'll check into that, thanks everyone for the help! I'm sure I'll be back with more questions on how to do that project haha

cruiser54

Hijacker:

Perhaps yours doesn't have limited slip and his does or your clutches in the diff are worn out?

2trackin

Pinion bearing.
But you can almost bet that its gona be more than that once its pulled apart. Had the issue on my silverado and ended up costing me well over 500 bones. I'm with the others, just replace the whole thing with a good used one.

94cherokeeman

Reccomended way to fix it without costing too much

jakeduece

How long can I wait to replace it? I'm pretty tight on funds right now! What happens if the pinion bearing fails on me cruising down the freeway? Thanks!

freegdr

pull drive shaft see if nuts loose yet?????

94cherokeeman

What nuts my drive shaft is tight

builtnotbought89'

You guys are getting things mixed up, that's why hijacking a thread isn't a good idea!

Jakeduece, the comment saying "pull your drive shaft to see how loose the nut is?" Was referring to your pinion nut on the yoke of your axle behind the driveline u joint.

94cherokee, the reason your friends "locks" & your doesn't is cause he has a LSD carrier which works as a limited slip not a locker! Yours most likely doesn't have this, but rather normal spider gears.

Let's keep things strait guys