Ron_H

Nicole;

Please keep us posted as you progress through re-installation.

borland

Nicole,

Wally makes a good point. If the a/c clutch is engaged, the bearing stops rotating against the compressor shaft, so the bearing noise should go away.

Thaddeus

Awesome work Nicole. Be sure to post the source of the bearing once you find it, I'll bet 30 other people will be following your lead (though hopefully not me) .

SharkSkin

Ah, so the bearing inner race lives on the compressor housing, rather than on the compressor shaft. Good to know. Somehow I had the idea that the bearing inner race pressed onto the compressor crankshaft, which would mean that the bearing stops turning with the clutch engaged. I've seen that configuration elsewhere. More than one way to skin a cat!

Nicole

Thanks for the info! How can I tell for sure that I have this exact type of compressor? My car is an early 1991 (VIN0102), and I have not seen any "code" on the compressor.

I'd hate to order the bearing and get the wrong one. And then I'll still need a shop to replace the bearing in the pulley.

Garth S

Often, this info may be in the owner's manual (in the glovebox): otherwise there is a name plate on the compressor, with all the pertinant data - which means a trip underneath to check.

SharkSkin

Nicole, King Bearing can match that bearing without knowing or caring what it came from. As long as the numbers on the side of the bearing are legible, it will be easy. They are on the seal, and perhaps etched into the side of the race. Even without that, they could get you an acceptable bearing just by measuring yours and taking into account the operating parameters: < 10K RPM, < 250°F. Sizes of bearings such as this one are standardized worldwide.

jpitman2

Nicole,
Well done, I did this myself a couple of years ago.
One last thing to watch for - the clutch face has a specified clearance from the pulley when disengaged - the WSM should give this, I dont recall at all what it is. It is controlled by spacers on the shaft before you fit the pulley back on the shaft splines IIRC.
jp 83 Euro S AT 48k

MBMB

What did you have in mind for a quick-detach belly pan?

Nicole

There was a washer that came out when I pulled the coupling off. I thought that once i have the bearing replaced, i'd just put everything back together as it was (including the washer). This way, the gap should not change, or should it?

borland

The compressor label plate is on the end facing the rear of the car, and should say Denso Type 10PA20C. I believe the earlier compressors require different compressor hoses, so not likely those were replaced too.

The washer goes under the clutch plate and positions the clutch for proper clearance. I took mine apart but only to clean around the shaft near the shaft seal, didn't have a bearing problem, my bearing still runs quite after 90K miles.

GT Jackson

Nicole: No more running to get longer wrenches for more torque. With a little imagination you can lock two wrenches together to double their length. Too late to get the camera for pix but if need be, tomorrow . . .

SharkSkin

It is possible that the air gap on the compressor clutch will change when you change the bearing. The replacement should be of identical dimensions, but there may be some slight difference. Also, if the old bearing was not pressed completely into place, a new, identical bearing -- properly installed -- will yield a different clearance.

It would be good to check it regardless. I couldn't find a spec for the later clutch, but for the early ones the air gap is specified as 0.4mm to 1.0mm.

ViribusUnits

1. Don't be afraid of the belts. They're easy to take off and replace. I do it all the time. Takes me maybe a half hour now.

Like wally says. The pully bearing is on the idler pully. The idler pully is connected by the belt to the crank shaft. Anytime the crank shaft is turning, so is the idler pully.

You don't want to have the force pressing sideways on the input shaft of the pump. That would mean that the sensitive seal on the frount of the pump would have to deal with play, and force caused by the belt. Instead it is better to have the bearing for the idler pully mounted to the compressor houseing. This away, all of the force from the belt goes straight to the houseing, instead of first going to the input shaft for the pump. This makes it much easyer to design the bearing and seals inside the pump. As a result, since the bearing is stoping friction between the pump caseing and the idler pully, it's always turning.

The problem here is something killed your bearing. The question is what killed your bearing? Two things will kill it, heat, and age. Your car isn't THAT old, so we're looking for something that got the bearing REALLY hot, melted the greese out and killed it. What could it be. One is a slipping clutch, the other is a bad pump. A slipping clutch can be caused by the head unit realy getting weak, but not going out. As a result it doesn't flow enough electricty to engage the magnetic clutch fully, and the clutch slips. When it slips, it gets REALLY hot. The pump can go bad if you don't have enough oil circulating through the pump for any reason. Say, low freon, it leaked out, and was never recharged, wrong freon/oil componation. Contamidation from another pump that locked up and put metal particals all throught the a/c system. Etc.

So, it doesn't look like your getting excessive scuffing on the clutch, (a sure sign of slipping), so that leaves...

Good luck, but the fates don't seem to be with you.

Nicole

Viribus: The car has 80k miles on it now, but I run the AC ALL the time. It is always charged and works fine otherwise. I have been wondering, if maybe the belt tension was too tight.

If you look at the pulley in the pictures above, do you see any unusual scuffing? I have no comparison, but it does not look overly worn to me. Not that I really have a clue...

Either way, a new bearing is hopefully available quickly, so the car is back on the road by next weekend. With or without belly pan...