anyone else have worn oem pulley's on the inside edge?
 

the last couple months, i've been chasing a squeak in the front of the car. the squeak changes based on rev's, thought it was a belt, changed the belt, still there.

every time i start the car, the squeak will start, and change with revs for about 15 minutes, and then dissipate. nothing catastrophic, but irritating trying to quietly leave my subdivision...

today, finally tried checking pulley's. one is barely noisy, but i think i found the unexpected cause. looks like the 2 stamped steel idler pulley mounting points protrude enough to rub on the bearing retainer collars.

https://i.imgur.com/4nmQW8R.jpg

https://i.imgur.com/3opd2KH.jpg

my suspicion is that the plastic rubbing off on the mounting point is the cause of my noise. side-benefit, one of these pulley's is the one that's slightly noisier.

so the question is, does anyone know if the idler pulley design was revised in the 2015+ updates? while i'm inclined to replace them with new, if the design remains the same, the new pulley's are going to suffer a similar fate...

is anyone else aware of a similar wear pattern in other '13-15 cars?

is it worth clearancing this area myself? the mounts are integral to the block, which i've got no intention to replace anytime soon, so i'd rather not mess up the block if i don't have to!

How close to the back of the pulley does the belt ride? Perhaps you can get a bearing spacer from McMaster Carr. Otherwise clearancing the block I guess. Seems like an odd problem though. I can't imagine Subaru would improperly design a bearing seat. Seeing as they've been putting them on every engine ever.

Simply replacing the pulleys will probably stave off the issue for another 50k miles though. Which would likely make it a non issue

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I think there is supposed to be a small washer behind the pulley as a spacer.

is there a part number for them?

A couple things:

https://www.ft86club.com/forums/showthread.php?t=133007

Notice the description for the replacement idler here:

https://www.sparksparts.com/v-2015-s...ts-and-pulleys

Accessory Drive Belt Idler Pulley
SU003-00500

Fits 86, FR-S Drive Belt Idler Pulley - Repair or Replace If you've noticed that the Drive belt on your Toyota is becoming worn or is making a squealing noise, your Drive belt Idler pulley may be worn out. Replacing your Drive belt Idler pulley may be the solution.


They almost make it sound like an expected maintenance item.

In all fairness, any moving part on a vehicle is an expected maintenance item at some point.

my concern isn't replacing the pulley. it's minimizing damage to the new pulley in the same manner, either by adding parts, or using a revised iteration of the pulley. i honestly think it's a mistake on subaru's part to even build a tensioner location like this without better clearances to the bearings rotating portions.

i agree that the one of the idler's might be bad, but i've got the same wear characteristics on both pulley's and i'd like to fix the wear pattern before throwing more parts at it.

A pulley from Rock Auto wouldn't even turn until I put a washer behind it. Just a generic flat washer.

thanks, i'll look into that then. you wouldn't happen to know which ID off-hand would you?

I know it's not exactly related but the idler pulley in our dryer is going bad. I tried fixing but I am coming to the realization it's like a ball joint and once it starts having issues you can't fix it and the only solution is a new pulley. Like the dryer, it's a wear and tear part and I don't think you have to worry about throwing more parts at it and chasing a bigger issue.

Is it a belt-slipping kind of squeak? I know it well and found the strangest issue.

Exactly. I can temporarily fix with some wd-40 but a couple days later it's back. I have a rebuild kit on order and will replace all the moving parts except the drum.

There are idler pulley noises, and there is belt squeak. I started getting a belt squeak a couple years ago but the belt was perfectly serviceable. Looking closely, I noticed some grains of sand had worked their way into the valleys of the belt grooves. The grains lifted the belt away from the little alternator pulley enough for it to slip in spots while under load for a few minutes after starting the engine.


Spent an hour carefully picking out all the tiny grains with the tip of a hard needle (from a drafting compass). Eliminated the squeak and I'm STILL using the original belt.

sorry,thought you were replying to the washing machine post.

yes, it definitely sounds like a rubber/belt squeak, and not a mechanical/metal squeak as i'd expect from a bearing. the 'chirp' is rpm dependent, but also sounds as a singular point in the belt striking a single pulley position, instead of a more rapid 'chirp' i would expect from a failed bearing assembly. i figured 50k in, it's not the worst thing to replace the belt anyways, though i was surprised the belt was squeaking already. i did find some chunks on the old belt that looked to indicate debris at the bottom of the pulley groove, but it was throughout every swath of the belt that i checked, which made it easier to replace the entire belt than spend a few hours picking all the pieces out for a part that was well-used..

thanks, i'll pull the belt again and check the pulley's, probably run a wire wheel over them all just to be safe

I apologize for the cryptic post. Was trying not to muscle in on the pulley conversation. I don't know why the belt picks up that stuff. Maybe all longitudinally mounted engines do that to serpentine belts. :iono:

yeah really doesn't make much sense, there's nothing obviously different about this setup than any other vehicle on the road. maybe the packaging/idler pulley radius' are smaller, which open up the grooves of the belt more for debris than other designs?

Maybe i am missing something but where is the wear on the pullies? Are you sure its not just time to replace the bearings? looking at the back of the pullies id say all their grease is gone.

i've got new pulley's sitting on the car ready to go in this weekend. my concern wasn't just replacing the pulley's but how the engine block is wearing into the retaining collar. i didn't want it to happen to the new pulley's.

i found some 14ga 5/8"x1" spacer bushings that that need minor clearancing, but ought to add the clearance i desire to keep the retainer from getting scored up again.

It is interesting how the seal rubbed just a smidge at the base of the mounts. Mine aren't like that. If the inner races on the new ones are wider, noticeably proud of the seal face, then it's a done deal. If you end up needing a spacer, keep it as thin as possible, IMHO. ...I think.


Actually, looking again, I don't know exactly what to make of it, Dammit. Now I want to go look at mine.

New one's are the same. Inner race is just shallower (3/1000?) than the retainer. A large flat washer(3/4" ID) held flat on the inner race visibly scuffs the lettering on the retainer collar.


They make 18ga spacer bushings that might be more preferable, my home depot only had 1 in stock though. I might try a different store to see if they've got more.

It's just weird to me as every similar bearing like this I've come across commercially has a mounting surface recess machined into the contact surface so as to hit only on the inner/outer bearing surface, but steer well clear by a full 1/8" of the retainer.

the pulley's definitely lost all their grease. they were rattling like a wrist trinket, but overall were still pretty solid.

definitely didn't help, probably would've cleared when new, but still not enough clearance IMO...

i realized made a mistake when i picked the prettier pulley's.

https://i.imgur.com/EJzQ1nL.jpg

these definitely didn't clear, wouldn't even spin freely when tightened down.

so the 18ga spacer bushings were a necessity, though honestly about 2x's the clearance i really needed.

problem was the oem washer didn't fit. so i had to do some trimming.
https://i.imgur.com/RiCDPul.jpg

otherwise went in fine, no more squeaking so far, but seems like the other idler pulley under the alternator has some play now...

https://i.imgur.com/uWt2PB7.jpg

FWIW I replaced the idler pulley in the dryer as well and no more squeaks there either.

This is the lesson learned here. If a bearing makes any noise at all, if it isn't silky smooth, it's shot. Period.