My car is starting to sound like an airplane ready to take off as speed increases... It fluctuates with speed, not RPMs... I'm thinking it's a wheel bearing, but I've had wheel bearings get bad in other cars, and it doesn't sound the same (my old car had a loud deep droning sound, but my F-Body sounds more pissed off than that... more aggressive sound).

I don't know my rear end components too well... Any ideas/feedback on what it might be? Thanks in advance.

 

Hey my car has the same howling sound, except only on warm start ups (like after ive driven then parked for oh an hour or so and then start up again) and only at idle. After driving it a little while the howling noise goes away. The service dept couldnt detect it because it intermitent. If you find out what it is let me know as well. Thanks.

 

Get that rear end in the air, and put it in gear, take a stethoscope and listen for sounds. If you can't pinpoint the sound, then chances are its a wheel/axle bearing, because they tend to only be loud under a load. If you still hear it, then try to pinpoint it and say where its coming from. Post back and let us know

Also.... if you replace one wheel bearing might as well do the other side as well... and while your at it replace the ring and pinion gears (since you have to practically dissassemble the rear anyway)....... if you do go this route then I recommend the Ratech deluxe ring and pinion install kit from Thunder Racing.... it has everything you need to refreshen your rear end.

 

How long has it been since you changed your rear gear oil and gasket? If it was recently and someone else did it for you, did they remember to add the limited slip additive and did they use the correct GM additive or did they use the approved 'equivalent'?

 

Thanks for the feedback. Unfortunately, the car is out of my hands now, so I now have to have a shop do the checking. Long story, but anyways...

I think that the Ratech deluxe install kit sounds like a good option, but since the car is now out of my hands, does anyone know about how much install will cost for that kit? Also, SporkLover, when you say you have to "practically disassemble the rear", would it be much more work to install a new set of gears in there? I may be putting in a 3.73 or 4.10 set if it's not much more work.

As for the rear gear oil/gasket, hasn't been changed to my knowledge for at least a year and 15,000 miles. What kind of schedule should I be following for the rear gear oil, and does anyone have any favorites when it comes to type of oil?

sspddmn, my howling sound is pretty constant and predictable, so I don't think it's the same problem, but I'll try to keep this thread updated and I'll probably be looking for more feedback as the problem gets diagnosed by the shop.

One last thing. Anybody know of any shops in NorCal (Sacramento) area that specialize in F-Bodies? Current plan is to take it to a local Firestone.

 

on my moms z28 the rear end started sounding the same way i though it was the rear end and it ended up just being a wheel bearing so thats what im guessing it is..

 

We change our rear gear oil about once per year or every 15,000 miles. I just go to the dealer and get the manufacturer's recommended oil and additive and the proper GM gasket. We don't do anything special. I can usually tell I'm due for a change when I start hearing the sounds that you are describing, in case I forget.

For my car, we get GM Vehicle Care Axle Lubricant SAE 80W-90 (#89021671)
and the GM Vehicle Care Limited Slip Axle Lubricant Additive (#1052358). I've always used manufacturer's recommendation for this particular thing on both my T/A's and it's always been fine. The first time we needed it changed, we let someone else change it and they used an approved 'equvalent' from NAPA or somewhere like that and the noise got worse. They actually thought my rear end was shot, so we replaced it (1000 dollars) only to learn it was a couple dollar bottle of additive that was the culprit the whole time. Don't even have to describe how pissed I was...Needless to say, we do it ourselves now. The additive stinks like ***, so don't get it all over yourself!

 

Thanks for the info... Sounds like I needed a gear oil change as well.... It doesn't sound like missing one change should be enough to cause this sound, but I'll definitely keep to a similar schedule once the car's back up and running.

 

sounds like a front pinion or carrier side bearing going bad, pretty common more so than a wheel bearing.
like someone else here said get it up in the air and listin to it..


if you have disc rear brakes could be that the e-brake shoes are dragging or the e-brake drums rusted and contacting the shoe try dragging the e-brake for a block or so.

 

Don't overlook the possibility of it being a bad tire...happens all the time, especially on lowered vehicles. Went through the process on my '98 Z28. Both rear wheel bearings, new fluid and additive. It helped, but the main culprit was a seperated belt in the right rear tire.

 

First thing we looked at was the disc brakes... they looked fine. Thanks for the suggestion.

At this point, I've gotten a monster quote of $800+ for parts and labor even before touching the ring and pinion, and $400+ more for the ring and pinion if there's something wrong there. Shop claimed that right rear axle needs replacing, but I haven't gotten complete clarification since I'm about 400 miles away and am not the one dealing with them in person. Parts to be replaced include the right rear axle, axle bearings, and some other bearings. Does that quote sound a little high? The shop's in the North California (Sacramento) area, if that makes a difference in price.

Have axles been known to go bad like that on a regular basis?

 

What kind of tire did you have, and was there anything you did that could have made it separate? Right now I've got cheap crap tires, and I'm just waiting til I run down the thread before getting some new tires, if not new rims.

 

I had a noise coming from the rear that sounded like a bad tire, almost like a thump thump thump that increased in frequency with the speed of the car. I put the car in the air and ran it, and it still made noise. It turned out to be a bad bearing/axle. Had them both replaced, and the sound is gone.

 

Well, there's Speed Engineering in Fresno, 3 hours away from Sacramento... that appears to be the closest sponsor shop. http://www.speed-eng.com/

Non-sponsor Black Magic Racing is an hour and a half away from Sacramento: http://www.blackmagic-racing.com/services/index.php

 

Nope... not much work at all.

I recommend you go to your local fbody boards and see if anyone can do it for better price. I got all of my bearings replaced and a new ring and pinion set for $200... of course I provided the parts.

 

Do a quick rotation and see if it helps with the noise. While the tire is off, take a good look at it to see if it's cupped or worn funny. If the noise persists', then I figure a wheel/axle bearing. Always start cheap and simple...

 

Thanks for the idea... I actually did just that right before reading this thread... Found a shop (non-sponsor) that specializes in diffs and rear ends that gave me an oral quote for all the work for ~$700, with ~$300 of that being labor. I'll probably go with them, and I'll probably source most of the parts from sponsors.

Are there any favorites for gear brands? I was thinking Motive or Precision or USGear, but I don't know if there's any real advantages in getting those gears over an OEM set supplied by the shop.

Also, would it be prudent to replace the diff even if it's not damaged? It's a stock Torsen for the 2000 Firebird Formulas, and I was thinking of going with a T2R just as an overkill option since it's all opened up. I haven't learned the condition of the diff yet, but I wasn't sure whether the diff was one of those things you do while you're in there. Plus, Sam Strano mentioned that 4.10s wouldn't work w/ the T2R in the 10 bolt, due to clearances, meaning I'd have to stick with 3.73s at most if I got a T2R.

 

I wish I could, but my parents (who currently have possession of the car) would think that fixing a toe-in condition would involve a new set of sneakers. My father no longer has the luxury of time and energy to work on cars, and asking him to rotate the tires and inspect for my car would involve him bringing it to a GM dealer and having it done for $200...

I'll keep that in the back of my mind for the next time this happens, though. Which will come far too soon with the 10-bolt.

 

Thanks for the links. Speed Engineering is a tad bit far, but I may look at Black Magic Racing. Do they have their address on their site? I couldn't find it with a quick look-over.

 

buy a Moser 12-bolt will be less money in the long run...those ten bolts are a train wreck...always breaking ... you could install yourself,I promise for about 2,400 with all the incidentals!!!Good luck !!!!