1KZTE eating alternator belts?

[OM617YOTA]

Anyone else having this issue? I'm having a heck of a time keeping alternator/WP belts on my Prado. AC belt, no issue.

Bando OEM equivalents, started squeaking very quickly, couldn't keep them from squeaking.

NAPA generic replacements, also squeaking quickly, couldn't keep them from squeaking, plus operating at the very limit of adjustment. These were not the right belt profile, wasn't surprised they didn't work out.

Now Toyota OEM Mitsuboshi belts. Even bought a belt tensioner gauge in case I've been doing it wrong, but same experience. Installed, tensioned, drove a couple hundred KM, retensioned, and I just had to tighten them again after less than 1k km because they started squeaking again.

Pulleys look fine and look to be in alignmnent, next time I have belts off I'll check alignmnet with a straight edge. Will also check alternator bearings. Water pump is new, although I'll check that too and see if it rumbles.

Running out of ideas here. Could a failing alternator be dragging more than usual and causing squeak? It's very definitely the alternator. Squeaks a little on startup, batteries recharge, squeak goes away. Drive for a bit, let things heat up, starts squeaking more and more, gets worse the longer I drive. Squeaks worse if I'm using headlights/HVAC/wipers/rear defroster. It's winter in Oregon, I'm using most of those most of the time right now. Let off the throttle and let the RPMs drop, and the squeaking gets immediately terrible. New belts lasting a few weeks tops.

Any ideas?

 

[OM617YOTA]

Alrighty, thinking my continued issues might not be belts at all. I definitely had a belt squeak and think I've fixed that, but think the current squeak is suspension or maybe brake related. Can't reproduce the squeak when not moving, with engine running. Accelerate and the squeak goes away, maintain speed and a little squeaking, coasting down a lot of squeaking, stopped no squeaking. Bet I have a heat shield or something rubbing.

 

[Eurasiaoverland]

In a few hours we've gone from definitely the alternator to thinking it's the suspension and/or a heatshield. Belt squeal may be episodic, but when audible it should be continuous dependent on engine speed, load, ambient temperature etc. Suspension does not make a continuous squeal, and it's hard to imagine it being a heatshield. How are your brake pads?

Checking the alternator is easy, there should be a little noise from the brushes making contact when you turn it, but no rumbling or roughness. It should continue to spin down if you spin the pulley by hand.

 

[OM617YOTA]

It's definitely something. Hence me asking for ideas and input.

Squeak is very linked to throttle and movement. Accelerating, no squeak. Maintaining speed, some squeak, let off throttle, BAD squeak. Yesterday at lunch time I crawled around and found an exhaust donut gasket that was easy to get movement in just by wiggling the exhaust system. Thought I might have heard a squeak when everything was shut off and I was moving the exhaust system by hand, but couldn't be sure. Bolts on the flange were tight, I loosened + retightened them. Driving home after work, I had a little squeak, then halfway home it went away. Silence. That'll be harder to diagnose.

Had tires put on immediately after buying the Prado, asked Les Scwab to inspect brakes while they were in there and check on pad/shoe life. They said all looks good, lots of life left, and I haven't peeked at them since.

Drove the pickup to work today and probably will again tomorrow, will do more digging this weekend. Pull the wheels off and inspect the brakes myself, etc.

 

[Eurasiaoverland]

Is the noise a continuous, farily even sound like tyres squealing? Or a ryhthmical or uneven squeaking/chirping? If you could describe it better or post a recording, that would help people. I'm having a hard time imagining how a 'squeak' can be confused with belt squeal.

 

[OM617YOTA]

Sounds similar-ish to wear indicators on brake pads, except brake application makes no difference. A continuous chirp might be a better way to describe it. I've had catalytic converter heat shields rubbing on exhaust systems make similar noises, and had a brake dust cover rub on a brake disc and make a similar noise. Not the same by any means, but similar. Hard to imagine if you've never had those happen I guess. Also keep in mind this was happening at the same time as actual belt squeal, which was resolved.

I'll try and get a recording, but for now it's stopped. Drive to work this morning was perfectly fine. Will continue with the inspections, I don't believe in things randomly fixing themselves.

 

[Eurasiaoverland]

Seems like it could be many things, but always the way that it diseappears when you want someone else to listen to it.

On my Hilux Surf, I once had a high pitch whine, almost like a turbo whine but very subtle. I only heard it occasionally but never really pinned it down. I'm pretty sure it turned out to be a noisy fan clutch. But I think that's a very unusual source of a squeal.

 

[OM617YOTA]

Inspected brakes. Fronts looked + moved fine, pads looked new.

One of the rears had a pebble next to one of the pads, might have been the issue, although I didn't see wear on the pebble from rubbing on anything. Both the rears had a shield that might have been vibrating against the caliper, I bent it slightly out of the way so it would still shield but also be well clear of the caliper. Pulled pads, cleaned everything up, re greased and re disc-brake-quieted as appropriate, reinstalled. Lots of life left. Couple maybes, but nothing that really stood out as definitely the issue.

Still quiet. Hard to track an issue that's not there anymore.

 

[OM617YOTA]

Noise started again. Took it to Les Schwab, noise stopped, they couldn't reproduce it. They looked it over, everything looked great, couldn't find anything. Next time the noise starts I'll try and stop in.

Such is the way of the universe.

 

[OM617YOTA]

Just an update.

Since I last posted in this thread, the squeal or chirp came back once, for less than two minutes and less than a mile. Still no clue what it is.

 

[Squash]

If it's belts let the unit idle for a while as batteries charge up after the glow and start cycle. Sometimes stepping on the fuel early while driving brings on the squeal...let it idle and listen.
For driving issues, I put the unit on 4 jack stands because invariably your going to find something to tinker with.
Take off the tires, run it through the gears and listen. Also let it idle in gear and walk about, looking and listening.
Whilst in the air is also a good time to grease driveshafts, knuckles and steering linkages.
Grease springs if you have them.
Check wheel bearings for play.
Oh, and crawl underneath, and marvel at the engineering.