chinook527

I have a 88 Turbo II that has a bad whine that seems to come from the rear Diff. The noise starts at 30 mph peaks in volume at 40 mph and decreases above 40 mph in volume. it doesn't matter what gear I am in at these speeds (ie. 40mph in 2nd or 40mph in 5th) the sound is identical. The whine is louder while accelerating or maintaining speed, and goes away while coasting. I am wondering if there is a problem with the differential or possibly with the mounts? The car has been lowered 1 - 1.5 inches by previous owner.

Any help would be appreciated!

Thanks
Mike

WonkoTheSane

iTrader: (2)

I've never heard of a whine being caused directly from the mounts. Start with the obvious, have you changed/checked the fluid lately? Differentials need love too

ilike2eatricers

Differential bearing(s). I had this horrible whining/whirring sound that was barely noticeable at 20mph but the faster I went the louder it got. At highway speeds it was very loud, swapped in another diff and it turned out to be some bearings, which ones I forget. Is it load dependent? Does it change pitch when you are on/off the gas?

chinook527

yes , it has fresh gear lube and is still full. It wasn't empty when I changed it, so I don't think the bearings were oil starved.

The noise doesn't change pitch much with load, but it goes away completely when you push in the clutch and coast. It does change pitch slightly with speed.

I read some other posts regarding different mounts (rubber,aluminum, poly) and some complained of louder rear end noise with the stiffer mounts. I will try to get a descent recording of the noise to post here for your analysis.

Thanks for the input!

Mike

WonkoTheSane

iTrader: (2)

Normally the louder rear end noise that people complain about is all of the squeaks and groans that a soft rubber mount absorb. Its not a whining at all. If your fluid is full, the I'm going to agree with ilike2eatricers, that its a bearing problem.

RETed

What "gear lube" did you use???


-Ted

redturbo

My car has the exact symptoms that u described Chinook,my car is an 88t2 manual ,i took the car to a local shop and had them check to see if i had any fluid in the rear diff,and the guy said it was almost completly empty.I went and bought penzoil syncromesh and had him put that in ,i did not notice any diffrence still have the whine.i picked up redline mt-90 the next day and i went back to shop and had them drain my tranny and put the redline in ,thinking that the noise might be from my tranny .still same problem ,about a week after this the whine has become much louder now and and starts to whine imediatly not like it did before when i used get to 35 or 40 miles per hour .so i am in the same boat as you i dont have a clue if its my rear or my tranny ,but my car has the same symptoms as your car when i am in nuetral or push the clutch pedal the sound disapers.i am hoping that it is the rear diff since the guy at the shop said it was almost empty, it would be much cheaper to replace or repair than a tranny.

ilike2eatricers

It's the diff bearings. I'm fairly positive. I stopped screwing around trying to figure out what it was and just swapped my diff. Never looked back. I have the old diff sitting at my house but havent got around to taking it apart to inspect it yet.

WonkoTheSane

iTrader: (2)

yeah, I'm out of my league here. I just got to look inside my first diff ever, but its' out of my dad's 85 GS, so it won't be of much help here