1127xj

I have noticed that in 4wd, there is a whining noise from the front end. It seems to be mostly when letting off the throttle and changes pitch if I accelerate. If I can hold a steady throttle, it is much quieter. In 2WD, the noise is completely absent. Should I assume this is a pinion bearing issue? It seems to have developed since I replaced the ball joints, but honestly I don't use 4WD often, so it could be coincidence. I had a leaking pinion seal replaced a couple years ago, but it was quiet after the replacement. Any suggestions?

cf1k1

Check your diff fluid.

1127xj

I have, it's full. Sorry, forgot to mention that.

cf1k1

Not talking about fluid levels... The actual condition of the oil

beefmobile

4-lo or 4-hi? normally in 4-lo, i've gotten a whine in all the Jeeps i've ever had...in fact, that's how i know 4x4 is working...

1127xj

4Hi. I haven't changed the fluid, but it was changed when the pinion seal was replaced.

1127xj

Without dumping it, it doesn't show any obvious signs of contamination.

1976Mustang

That would be the transfer case, all transmissions/transfer cases make that noise in really slow gears. My Ranger does it in first. No clue what causes it though, something i want to figure out.

1976Mustang

Now that i think about it, my rear diff makes that noise at highway speed, i always figured it was normal... I'm thinking otherwise now.

1127xj

This is a new noise, don't believe it's normal because it was never there before.

freegdr

Check tc fliud level lately?

1127xj

yep, it's full.

1127xj

BTW, I did bring it to the dealer, and was told something is going in the ft. diff. or tc, but they were not sure what it is. They recommended I drive it until it gets louder so they can pinpoint it. Then they charged me $80 for "diagnosis." I already knew that much, thanks a bunch. This is why I rarely visit dealers, what a load of crap...

1976Mustang

I ONLY go to the dealer if i need Mopar parts in a hurry.
IDK about all AAMCO's, but the one i always go to usually diagnoses for free. They tore my transmission apart a week ago free of charge. I'm sure you can find a place that does free diagnostics.

coloradocherokee

very true...found this out when i changed mine....looked like coal water...previous owner mustuve never changed it..in fact myb it had never been changed at all