Whine/howl from rear end? Versatrak-AWD

[sparky66]

I have an 02 silhouette AWD (Versatrak), 94k mi. It has a whine/howl that appears to be coming from the rear of the vehicle. Could it be the AWD? I have never serviced it. Also, I recently put new tires on the front and not rear. Same P-size tire, but diff brand. Any suggestions on where to start?

[merc81]

I've always been told that with awd, you need to keep the tires the same; never change only front or only rear. The idea is the wheels must rotate at the same speed and even if the tires were same kind, worn rears and new front will rotate at different rates.

Only awd I've experienced was the astro model. When it had different tires on front than the back set, it whined and I think ruined the awd before I figured out what was going on. The awd light always came on at random times after that although it seemed to work ok.
John

[83cutlass]

yeah there is a problem with those rear diffs being noisey. The local GM dealer should be able to help you out. There has been a couple service bulletins out there to fix it. Sometimes a fluid change fixes it, sometime a replacement diff fixes it.

[rdh2]

Originally Posted by sparky66

I have an 02 silhouette AWD (Versatrak), 94k mi. It has a whine/howl that appears to be coming from the rear of the vehicle. Could it be the AWD? I have never serviced it. Also, I recently put new tires on the front and not rear. Same P-size tire, but diff brand. Any suggestions on where to start?

I have had the same problem on my '02 with 115,000 miles. It started after I had to have a rear tire replaced under warranty. The other rear tire was worn enough to cause a rotational difference between the tires. I was able to lessent the noise by rotating the tires, keeping the newer tire on the front.

It is ridiculous that GM expects all tires to be the same all the time. You aren't replacing all 4 tires for a sidewall cut on one of them at 20,000 miles. I have the GM bulletins as pdf files. PM me if you need a copy of one.





GM also has this bulletin on driveshaft noise. The service bulletin kit is about $500.

[ilttlc]

Wow, this sounds exactly like my problem. Immediately after replacing the tires on our '02, it started howling as we went down the road. But we put all new tires on it. The sound rises and falls with the van's speed, not the engine speed. I guess I will try rotating the tires. Any other thoughts/suggestions?

[ilttlc]

When I first heard the howl, I thought that I had a wheel hub going bad. The responses here got me wondering. But I still think the problem is a wheel hub.

The differential groan on low speed/parking lot turns is well covered on this forum. My van suffers from this too. But this howl is something different altogether.

I did another search and found the same questions being asked about Azteks on another forum. One poor lady spent $6,000 on a new rear end, but the whine remained. The conclusion was a bad wheel hub.

The weird thing is that almost all the complaints start after new tires are put on! Anyone have more insight?

I have two new hubs on order and will be putting them on over the weekend. I will post about how it turns out.

[ilttlc]

FINALLY got a chance to work on my Olds. The hubs took longer than expected to come in and then work intervened. I Replaced both rear wheel hubs last week. The whine is gone and the ABS light went off.

If you have this whine, try making some hard left and right hand turns at speed. If the sound goes away, it is likely a wheel hub going bad.

Still, does anyone have any idea why this seems to happen after getting new tires???