Belt tensioner wobble?

[New2Subaru1]

I have a 94 subaru legacy wagon, and ive noticed the belt pullet (the one located down from the alternator) has a little wobble to it at idle. Is this alright? How soon would I need to fix it? it doesnt effect the way it runs or drives. 

[DaveT]

I'd replace the bearing.  It's going to fail soon.  I don't know the specifics of that model / year, but usually those idlers use a standard ball bearing.  Numbers usually printed on the side seals of the bearing.  Get one with contact seals. 

[Bushwick]

If you can't get to it immediately, with engine OFF, stick you finger into some HD axle bearing grease, and press it into the crevice between the pulley and bearing race. Need belt off as well. Keep pressing the grease into the recess, then spin the pulley by hand, wiping excess off the pulley front (do NOT let it get on or in the pulley grooves).

 

Get enough grease in there that the bearings are effectively repacked, and it should remove the wobble for the time being unless the bearings are physically ground down. The grease thickness will recenter the pulley.

 

I did this on a couple of mine (non interference engine) that were getting dry but still spun smoothly, and 15k miles later they are still holding. At least 2 of them had a minor wobble from the lack of grease film for the bearings to ride on. After repacking, they recentered themselves. 

 

Again, bearings can't be physically damaged and pulley must still spin smoothly, and ideally any rust needs blasted out. I'll replace mine next time, but since I wasn't sure if the car would even run a full year when I did mine, I wanted to avoid dumping too much into it until the engine proved it'd stay running (which it has). Bearings are still quiet too and this is the 3rd year running it.

 

Also, for best results, remove the pulley, spray out the bearing crevice if rusted, let it dry, then try and work the fresh grease into each side front/back and spin occasionally. You can see into the crevice (barely) and should be able to tell when it's completely wet and packed.

 

After reassembly, start engine and idle it for 10 minutes and watch the pulley for odd wobbling or noise. If it looks OK, give it some gas and watch it further.

 

EDIT: When I say mine had a minor wobble, I'm referring to minor lateral movement, like grabbing pulley OD while still bolted in but w/o belt on it, and it could move up/down left/right slightly or 12 to 6 o'clock, 9 to 3 o'clock. Once fresh grease film was in there, it felt firmly in place.

Edited May 13, 2016 by Bushwick

[Rooster2]

Or............instead of trying to extend the life of the existing bearing, that probably came with the car, simply replace the pulley. They don't cost much, ez to install, and you will be certain that it won't give you any trouble.

[1 Lucky Texan]

Just to be clear - you aren't talking about the crank pulley are you?

 

sometimes, people don't torque those properly. And sometimes the rubber between the outer and inner pieces degrades. Those issues would need attention.

[Fairtax4me]

Like 1LT said,

Crank pulley / harmonic balancer is the large one straight down from the alternator.

 

It could just be wobbly.

It could have a loose bolt, and the whole pulley is about to wobble off and damage the end of the crankshaft.

It could have deteriorated rubber section and the outer portion of the pulley is about to spin off and chuck the belts.

[Bushwick]

Or............instead of trying to extend the life of the existing bearing, that probably came with the car, simply replace the pulley. They don't cost much, ez to install, and you will be certain that it won't give you any trouble.

 

Before we became the "throw away" generation, we were the fix it or maintain it generation.

 

What actually causes the pulleys to fail is they dry out and eat the bearings up, then can come apart. If you catch one before it can get completely dry, you can prolong their life. There's no magic or wishful thinking here. It's a ball bearing in a race. Keep them greased and they'll stay working. 

Edited May 14, 2016 by Bushwick