My car makes a howling noise when driving above 40mph. The sound is coming from the rear end. I recently replaced the rear axle seals. The drivers side was damp and the passenger was fine but since I had it apart I did both. I then refilled the rear with GM diff fluid.

The interesting part is if I put the car in neutral the noise disappears, then back into gear the noise is back. This makes me believe it needs to have pressure on it to cause the noise.

Has anyone else experience this howling? Do they know what might be causing it? Pinion bearing?

My transmission was rebuilt about 6000 miles ago. But when it went it made a howling noise. But I could hear it through the console. Could it be Trans related and resonating through the driveshaft to the rear? Or could it be the driveshaft?

 

Anyone, Could it be gears whining?

 

My guess is the gears. When you put it into neutral, the gears dont have a load on them. When you put it back in drive, the load comes back. Gears might be getting worn.

 

The noise does fade in Neutral. So I would assume it is the strain on the gears. It still has a slight noise in neutral, but it is almost inaudible.

Maybe I will just wait it out and rebuild the rear end in July. Go with 3.73's or something.

If it is gears, will they just finally give out or will the noise just drive me to changing them?

 

My dads truck did the same thing...he would be idling in P and no whine...put it any drive gear R or D and would whine like it had a blower.....it was the Converter.....check it out...

 

Did his truck whine louder at certain speeds though? At 40-50mph the car is the noisiest. Then after that it comes back down. But if I pop it in neutral the noise goes to a minimal.

Where did the sound come through the truck. Mine sounds rear. I should hear it through the console if its converter?

 

Tear out the gears and install a set of bigger gears like 3:73 or 4:10.

 

could be the bearings on the carrier as well.
I would pop the cover off again and check for any play in the carrier, and check for pinion to ring mesh.

 

Sounds just like a problem I was having. Turns out the bearings were pitted. New bearings =

 

Alright. What is acceptable play? None? My father is a mechanic so when I am stuck on something I would have him help. I live 2000km away from him now. Very mechanically inclined so anything to read or information is great before I pull that cover off again.

You are on thirdgen.org (recognize the name)? I use to frequent that board a few years back. Had an 87 V-6 firebird, great people and resource.


Could be a possibility. The car did sit for 6 months. The bearings may have pitted from sitting in one spot.

 

Carrier should have virtually no play at all.