Tweety Bird is in my Differential!

[Darkwriter77]

At first I thought it was the U-joints on my stock driveshaft. Then I thought it was the rear bearing of the tranny. With both of those replaced now, and no change in the condition, I think ... THINK that it's my pinion bearing. It's hard to tell precisely where it's coming from, other than somewhere of the vicinity of under the rear seat (vaguely).

I'm doubting it's an axle bearing, since most have described that as being a whirring or growling sort of noise - this is a high-pitched metal-on-metal "scree-yee-yee-yee-yee" that goes up in RPM with wheel speed. It depends somewhat upon throttle input, largely only does it at low parking lot speeds, makes a high-pitched howl briefly when I take off aggressively, and it completely vanishes after about 3 to 5 minutes of driving. Thinking it also might have something to do with the weird vibration at 45 to 50 mph.

Rear gear fluid level's good (just changed, no leaks), no sign of metal shavings in there as of yet. Does this sound typical of a pinion bearing? It's been going on for a few months, now, and hasn't gotten any worse, but I'm afraid to take this thing out for any long drives, as I don't want anything overheating and seizing up or melting together.

As always, many, many, many thanks in advance!

 

[Darkwriter77]

Anyone had a pinion bearing go out before? Anyone?

 

[Daggar]

I have a hard time imagining any bearing immersed in lubricant making a high pitched squeel.

 

[superhuaman]

Jack up the car and see if there's any play in the pinion flange (side-to-side, in-and-out, etc) If there is, you have a pinion (bearing?) problem. Also, have a friend watch the rear wheels while you drive slowly, to see if the problem occurs once per wheel revolution, or more than that. If it is once per wheel rev, it's probably carrier or axle related. If it is like 3 or 4 times per wheel rev, then it is a pinion problem (cuz your gears are probably somewhere between 2:73 and 3:73).

 

[Darkwriter77]

'Kay. I'll give it a peek tomorrow mornin'. Many thanks!

 

[superhuaman]

If it is like 3 or 4 times per wheel rev, then it is a pinion problem (cuz your gears are probably somewhere between 2:73 and 3:73).

D'oh. Sorry Darkwriter77, I didn't see in your sig that you have 4.10 gears. Oh well..

 

[darthcual]

Do like in the darwin awards story i read. Guy was trying to find a noise so he attached himself to the underside of his vehicle while a friend of his drove the van down the road. I cant remember if he found the noise or not but he did die when he got wrapped up in the driveshaft. On a side note dark, I would put the rear up on jack stands, making sure to CHOCK the front wheels in front and back. Then have a friend run the engine while you pinpoint exactly where the noise is coming from. If it is tweety, dont try hiring sylvester, for his track record for catching and killing him sucks.

 

[superhuaman]

Nice!! Thanks, man!

 

[Darkwriter77]

It actually sounds more like it's only squeaking once or twice per wheel revolution which would, now that you mention it, probably seem to indicate something more towards the wheel-end of the rear than before the gears. My boss at work heard the squeak as I took off for lunch, and said it sounded more like a brake-related issue, but I dunno ... I've hosed it all clean with brake cleaner, already, and the shoes are almost brand new with no drag on 'em. E-brake works just fine, too, although I do seem to have to pull it up pretty firmly to get it to hold enough on inclines - maybe a bit of lube/adjusting of that should fix it.

Perhaps the backing shield behind the springs/shoes could be rubbing against the drum...?

 

[superhuaman]

Perhaps the backing shield behind the springs/shoes could be rubbing against the drum...?

That's possible, especially if the backing plate is bent. Also, your drum could be warped, and rubbing on the shoes. But that would probably make a lower pitched noise that what you described. Does the noise still go away after a bit, or is it there all the time now?

 

[Darkwriter77]

Pulled off both wheels again, no sign of rubbing or dragging. Plenty of clearance between the drums and backing plates. Fluid level in the diff. is right where it should be, no signs of leakage. Put both rear wheels in the air, crawled under there, unhooked the driveshaft, and spun the wheels by hand. The squeaking is DEFINITELY coming from the front-end of the differential.

Called around to get price quotes on getting the pinion bearing changed out. Of course, they all wanted to try to sell me on a full rear-end rebuild, but I know it's nothing THAT severe - no metal shavings in the rear fluid or any weird slack in the rear axles or that sorta thing. That, and they all swore up and down that there's no way the pinion bearing could make a high-pitched squeak like mine is, that is should be a low-pitched growling noise, and that it should make it at ALL speeds (not just low speeds for the first couple o' miles). Why do I get all the special one-off automotive problems in the world? ... all on the same car?

And to top it off, I found a friggin' nail in my right-rear tire while it was off. Ugh. Oh, and now Satan is trying to re-inhabit my engine bay once more with the power loss/surging nonsense again. Pretty sure it's just the TFI module again, which is under warranty, but still ... AAARRRGHH! What next?

I've poured over exploded diagrams of the rear end, and I can't see anything else but the pinion bearing that could be making a squeak like that from the front-end of the vehicle. Unless, of course, Satan has moved from the front to the rear of my car, now...

Ideas? Suggestions? Recommendations for a good exorcist?

 

[superhuaman]

Ooh, I just thought of something.. PINION SEAL rubbing on the yoke. If the seal gets dry it will make a noise. It might even score the yoke if its bad enough. The yoke has that plastic protector thing on it, so you can't really see the seal. I would say get a price for pinion seal replacement, or you could do it yourself. It would take a new crush sleeve though (to do it right).

Spray some like WD 40 or something in between the metal part of the seal, and the plastic seal shield on the yoke, and see if the noise goes away.

 

[darthcual]

My vote is for the self adjusting nut. Take those puppies out, and brakleen them things and slap them back in. Be sure to note which one goes where because one of them is reverse threaded. On second thought you should always do one at a time so you have the other side to look at for reference.

Edit* sometimes i just ignore a noise and it goes away on its own. Have you tried this approach yet?

 

[superhuaman]

My vote is for the self adjusting nut.

Why would that make the noise? It doesn't rotate with the wheels, and he hears the noise without using the brakes.

sometimes i just ignore a noise and it goes away on its own.

That MIGHT work, but it may just get worse, too.

 

[darthcual]

Hey! just noticed ur extra feature of changing lanes when braking. It must be your brakes! Making the noise that is. The cylinder needs to be changed in the rear drum there. So that could be ur noise problem as well?

 

[darthcual]

Why would that make the noise? It doesn't rotate with the wheels, and he hears the noise without using the brakes.

A)the brakes are not adjusting properly

That MIGHT work, but it may just get worse, too.

B) Oh it DOES work, tried and true method, I've done it several times

 

[superhuaman]

B) Oh it DOES work, tried and true method, I've done it several times

Ok ok, but he said the noise was coming from the front of the diff. And as far as I know, the brakes don't adjust themselves unless you use them.

 

[Darkwriter77]

The lane-changing "feature" is the lower ball joints that have been beaten to death over their 245k lifespan - I can get some pretty groovy up-down wiggle action going on by hand with the front wheels jacked up in the air. The pull to the left suddenly turns into a pull to the right if I hit a bump going the other way while braking, as well. Good guess, though.

The dry pinion seal theory sounds ... well, sound. I went ahead and gave it a good hosing-down with some Seafoam Deep Creep, and it seems to have gone away for the moment ... but then again, I've been driving it around a bit today, and it only does it for the first few miles of each day (and only at takeoff, parking lots, or goosing the throttle a bit), so tomorrow morning will tell if it's done the trick. If the seal is the source of all the noise, then I may go back under there and get crazy with a can of white lithium grease or something a little more long-lasting. Again, not a drop of leaked gear fluid from anywhere around the diff or the axles (or brake fluid, for that matter).

Kinda tough to ignore it, being that it's such a hideous screech in the morning (oh, how my neighbors must love all the sounds of my car), but if the only fix for it is a new seal ... which involves tearing apart the diff and such ... I just may have to live with it. Maybe make up some story about how I have "Strange" brand axles and they make "strange" noises, or something...

Many thanks for the input.

 

[superhuaman]

Darkwriter77, if the lube doesn't do the trick, it may be the oil slinger, which is right behind the seal. It's like a paper-thin metal washer that keeps the oil from directly hitting the seal. See, the seal is rubber in the middle, and it's bonded to a metal housing. So if that oil slinger is rubbing the seal, that could be it too. It seems like I think of something new with every post, LOL. Usually the seals willleak if they squeal, so it's probably not the seal itself. But the replacement procedure is the same for the seal and for the slinger.
Good luck!

 

[darthcual]

Its a regular cacaphony of sound from your car.
Extra Feature-The London Philharmonic inhabits darkwriters car