lachrimae

Well, I've been reading through the archives but haven't yet been able to diagnose my problem.

My '92 AC clutch (pulley) is completely siezed (with electrical connector unplugged) but I am able to turn the inner part that connects to the compressor rod. According to the archives this would normally indicate a clutch issue but I also have a bunch of oil that leaked as well.

Does this mean that I need a new clutch and a new gasket/seal kit for the compressor (as installed here) or should I just buy a new compressor with clutch?

This originally started when I was driving and noticed that my AC was blowing hot, then I noticed white smoke coming from under the hood. Once I pulled over my battery was near-dead and there was a fair amount of (dark black) oil that leaked from the compressor area.

One other thing: Does the oil indicate that my system has already been evacuated or do I still need to have that done at a shop? Might be a stupid question but how can I get my vette to a shop when the clutch pulley is siezed (without having to pay for a tow)?

Thanks in advance,
Mark

toptechx6

It sounds to me like you need a compressor and clutch, if the compressor did come apart it would be a good idea to replace the accumulator and orifice tube, some also recommend installing a filter after compressor replacement.
Your 92 has a water pump that is driven directly off the camshaft so if you remove the belt you can drive the car to a shop without overheating. Understand the alternator will not charge the battery and the power steering will not work so I would choose a shop that is near by, good luck.

lachrimae

TopTech, thanks for the reply & info about driving w/out a belt.

I'll keep this thread updated as I work my way through this project

car5car

Maybe it is possible to find a belt working w/o ac.
Ask auto parts store if they can find belt by length, then get a rope and install it to see if it is possible at all. If you decide that it is, measure rope and go buy a belt.
Some people remove AC, I guess they can find a belt.

vettme

Time for a New comp.

Hooked on Vettes

If you can turn the clutch hub shown as item 7 in the diagram which
is attached to the compressor shaft, that indicates the compressor is not seized.

If you slip the serpentine belt off the AC clutch pulley, show as item 3 in the diagram, the pulley should spin freely on the compressor shaft.

A common problem is the clutch coil, show as item 6, which is located behind the pulley melts and oozes a black melted substance.

Here's a picture of the clutch coil assembly.

Some people have mentioned they changed the clutch coil by carefully bending the AC hoses to get the clearance to get the clutch off of the compressor.

lachrimae

Hooked, thanks for posting up, you may have just saved me some $.

In my case, #7 spins with slight resistance, but #3 is completely seized.
You mention a black substance that oozes from the clutch coil. Well, that's a pretty good description of what has come out of the compressor...the stuff is pretty thick, dark black and hard to wash off (certainly not like mineral oil or whatever is in the Compressor).

I'll do some forum searches on replacing the clutch to see if I can't replace it w/out removing the AC lines. <crossing fingers>

lachrimae

I removed the Pressure Plate (7) and Retaining Ring (2) but am stuck on how to get the Rotor (3) off.

I have used some PB weld which allows it to turn a little bit but I can't seem to knock it off. I think it's pretty much welded to the Stator/Clutch (6) because the Stator rotates when I rotate the Rotor.

Is this the point where the Rotor ends & the Stator begins?


I see in another post where they had a similar problem and started dremeling off the six bridge points on the Rotor but I'd rather not if I can avoid it.

Am I seeing three points of the Retaining Ring (2) in the inner part of the compressor shaft in this pic? I'm wondering if I couldn't push them outwards and release the stator & rotor at the same time...


By the way, this gunk that leaked out is so stubborn, it could stain motor oil. Here's what some of it looks like on my hood:


Thanks,
Mark

lachrimae

Figured it out. Mallet + wooden dowel is what finally jarred the Rotor off of the Stator. Once the rotor & inner circlip were off, the stator slid right off.

Turns out the Stator is completely hidden behind the face of the rotor.

Here are some pics for future reference:

Rotor (Pulley) front. Bent the metal flange during removal...

Rotor Back

Stator (Clutch coil) Front. Pretty nasty

Stator Back


Time to order some parts & then hope it was indeed the clutch. Otherwise it will cost more $ to buy the clutch & then the compressor separately.

Bob2.0

I'm working on the same thing but I'm having a heck of a time finding a replacement bearing. Mine measures 1.2" inner diameter, and OEM lists 1.57. So, obviously the one I bought won't fit. What did you do?

lachrimae

hmmm, I ordered my parts through O'Reilly and didn't run into any fitment issues so I'm not sure.

I guess I never updated the thread, but the new clutch fixed the problem .

Bob2.0

It was hell but I did get the old bearing out and I got the new one in. I bent my inner flange too however. Did you get a new one, or will it work without it?

lachrimae

I didn't wind up pulling the bearing from the rotor, I replaced the entire clutch (rotor & stator).

Here's what the new parts looked like:








No flange on the replacement...

Good luck!

Bob2.0

Thanks for all of the great shots. That clears up the flange issue too. I was worried about that. My compressor is find so if my fix doesn't work, I'll just do like you did and get new parts.

One last question... where do the shims go? The service manual makes it look like they go on the bolt going into the compressor shaft. They just fell out in my hand when I pulled off the pressure plate so I didn't know where they went.

As soon as I figure that out, I should be ready to reinstall....

Thanks again for your help.

Bob2.0

Nevermind on the shim issue. I found a video that shows that the bolt threads through them, and insures the proper air gap between the plate and the hub.

I'm ready to install now!!! Yay!

Bob2.0

Okay, well, at long last I was able to put on the rotor with the new bearing in it. It slipped on fine, but when I went to turn it by hand it was smooth for a half of a revolution, and then it would bind up and get harder to turn, then easy then hard.

Figuring that I had nothing to lose, I put the old spare serpentine belt on and let it run. AC blew nice and cold, but after while I could visually see the clutch plate slow down and speed up. I began to smell the belt cooking so I shut it down.

I'm guessing that I warped the rotor, or that the bearing isn't in completely straight. I'm also guessing that a new clutch assembly is in my future. Any other ideas first?

Bob

Bob2.0

lachrimae--where did you get your parts? I am having trouble finding them separate.

lachrimae

Hi Bob,

I bought them from O'Reilly. Unfortunately I don't have the part numbers that I ordered but if you go in they should be able to look them up.

Mark

SunCr

Most are easy then hard when you turn the shaft over - it's a compressor - there are pistons, etc. Now if you can't turn the shaft or need a wrench to turn it, that usually means the compressor is shot. If it's the pulley that won't freewheel, it needs a new bearing or the concentric is grooved/out of round and the compressor is shot (I've never been able to find a source for shafts or any of the innards; nor can I find any specs, but if you mic it at 3 or 4 points, those points should all be the same).

Did you shim it so that there is .020 inch clearance between the faceplate and hub? Too much of a gap and it will slip. Too little and it will make contact when it cycles and ruin it. Ditto if the snap rings aren't fully seated. The coil and hub will unseat and it all gets mashed together. It's really hard working on these LT setups with the compressor installed because the Main Hose comes right over the front of it.

Actually it's difficult to diagnose without being there - both of these look/sound like shaft seal failures which can trash the assembly, but if it's not spewing oil on the hood (and hopefully it isn't), I suppose it's worth a shot at just repairing the clutch. Now if it is spewing oil, it's probably about out of it and once it's gone, it going to chuckup a bunch of shrapnel. And since there's no dipstick, you want to be sure of what the problem is.