Mysterious Belt/Pully Squeak

[jdenison]

2000 4Runner V6. I have a serious squeak in cold weather that goes away when the engine warms up. It happens when I'm up to speed and let off the gas and the engine backs down to about 1500-1700rpm. I cannot reproduce the squeak while the car is sitting still on park or neutral. I've changed the belts and tried varying degrees of tightness. HELP! I'm trying to avoid changing out multiple parts.

 

[004Gunner]

Are you sure it's a belt/pulley? The fact that it cannot be reproduced while in park or neutral suggests that it may be coming from somewhere else. I had a problem that sounds identical to yours and was caused by a leaking rear axle seal. I have had way too much experience with these so I would recommend checking it out. Also it may help to have various windows rolled down while driving to try to locate the problem.

 

[jdenison]

That is an interesting point. Next, I'll have my girlfriend sit in the back and switch sides while I'm rolling and the windows are down. Maybe she could determine left/right/front/back. Unfortunately, it doesn't do it for long or at all in the warm weather. The Toyota Master Mechanic could only replicate it for a few moments. Said he's never seen anything like it. In the winter, it is WAY LOUD. I love this car, but this issue pisses me off.

 

[004Gunner]

Yeah that was the issue I had. I ended up checking weather reports to see what morning would be good to bring it to a mechanic. Also try to determine if the noise corresponds better to the rpms or to the rotation of the tires. . . just another way to narrow it down

 

[jdenison]

Could you actually see the leak? I can't see anything. My mechanic buddy says I may be able to smell it if I pull the break drum.

 

[004Gunner]

You can see fluid on the backing plate of the brake drum and if it gets bad it will be on the wheel too. As far as smell goes I never did notice anything unusual. Any luck on narrowing it down by location?

 

[jdenison]

Pulled break drums. Neither was seriously greasy. One was a little more than the other. Only on essentially the deepest recesses towards the axle could I find something that looked a tad slick. Here's the picture.

 

[jdenison]

Here's where I got what's on my finger.

 

[jdenison]

Too hot here now to reproduce the sound. I'm thinking about a safe way to get it on jack stands and get her rolling in the drive way and maybe hear that way. Will have to be colder.

 

[004Gunner]

That picture looks like there is a minor leak from the axle seal. It's hard to say for sure but the darker areas towards the center combined with what's on your fingers indicates a seal leak. There should not be anything slick around there.

 

[jdenison]

Sent pictures to buddy mechanic and the local Toyota dlrshp. They both agree that leak is minor.

Buddy had a thought. It is likely that your real drive shaft was removed to redo the axle seals. He said that a joint that is leaking rarely squeaks. A dry one would. The drive shaft seal could have been the issue and was fixed when its seal was reinstalled during the axle seal job.

He said next time its cold, for me to squirt some lithium grease into the drive shaft seal and see if the squeak stops. If it does, just redo the drive shaft seals, which are much easier than the axles.

The saga continues.

 

[004Gunner]

That is a good thought but it wasn't listed on the parts or labor. Of course at the time it was done under warranty so maybe they didn't bother listing it. I have pulled the axle myself and it isn't neccessary to remove anything around the drive shaft. My thought was that internal components were not getting enough lube which created the squeak. Good thing you found your leak when it was minor. It looks like your brakes are still ok.

 

[jdenison]

Winter Again

Winter has arrived and the noise is back. I've jacked up each rear wheel one at a time, got the wheel spinning and the noise is the same each time. The sound seems to be coming from under the car in the rear. I took it into a reputable local shop and they swear its the breaks. I don't believe it for a bunch of reasons. They didn't seem to have their hearts in the job .. they were slammed with work and they didn't even try to sell me a brake job. They suggested toyota break shoes and turning the drums. The axle seals don't seem to have leaked since the pictures I posted last year. The one common thread seems to be the the drive shaft, ujoints and the components there. Any thoughts?

 

[Hacker]

2000 4Runner V6. I have a serious squeak in cold weather that goes away when the engine warms up. It happens when I'm up to speed and let off the gas and the engine backs down to about 1500-1700rpm.

This is PRECISELY the problem I've developed this winter in my '99.

Other threads, both here and on YotaTech, indicate it may be a bad belt or a worn out pulley.

Did you ever resolve this? Just don't want to go chasing things when it sounds like you had exactly the same problem I do.