'86 Toyota truck squeals when cold; only when driving

I just acquired this truck from my parents with an actual 50k miles. It's a 2wd extra cab SR5. It seems fine except for an odd squeal while driving when the engine is cold. The sound isn't subtle. It is a fairly high-pitched whine or squeal that warbles slightly at the frequency of the driveshaft (I'm guessing). I can change it's tone and loudness by varying the throttle... no noise when coasting. If I start the truck and let it warm up for ~10 minutes, it doesn't make the noise at all... normally it takes 2 or 3 miles for it to quiet down.

Any ideas? It doesn't make sense to me. If it was a belt or something in the engine, it should make noise even when I'm not driving it. On the other hand I don't understand why warming up the engine would silence the drivetrain.

Thanks...

Reply to
rruffrruff
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Belt squeel. Try replacing the drive belts. There are 2, they cost under $10 each. If the belts don't fix the squeel, it can be the idler bearing on the upper belt tensioner.

Reply to
Ernie Leimkuhler

I did increase the *tension* on the belts and it didn't help. It also doesn't make sense to me that I'd need to be driving to make them squeal. I can put it in D with the brake on and gun the engine, turn the steering back and forth, and there is no noise. The truck needs to be moving. I replaced an idler bearing on an '84 I used to have... it wasn't sounding like this, though.

Yes, this is an automatic... forgot to mention that. Seems to shift fine.

Reply to
rruffrruff

Does the squeal vary with speed, like maybe a disc brake pad?

Reply to
TOM

I can vary the sound quite noticably by varying the throttle application, but it isn't really speed dependent... plus there is no noise when coasting, so I don't think that could be it.

Reply to
rruffrruff

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