Paul Waterloo

Was driving the car the other day, parked it, and then when I got back in it, it started squealing like a pig. Quickly figured out the alternator belt had become untensioned, so I drove it home. It continued to squeal and generally sound very bad, but a few times it caught and battery voltage returned to normal.

Today I dropped the belly pan and I see the side that is connected to the engine pivot is hanging in air....no bolt in it.

Look into the belly pan and see the bolt and sleeve are there! One great triumph!



I grab the adjustment strut.....and then the other end just shears in my hand with so little pressure. Luckily the local parts place can get an OEM one for me this afternoon so I can install it while the front is jacked up. $85, a few more bucks than online, but it will be done today.

I don't know if this is the OEM compressor / mount, I know it was replaced two owners ago:



And you can see the opposite end of the sheared end had the locknut loose.



Here it is from last fall, it was locked in place....but most likely not that tight:



Hopefully it will be an easy fix.

jeff968

Ha, every once and a while you get lucky (your bolt staying with you). Good luck.

Paul Waterloo

Balance is restored, put the new tensioner in...working normally again.

docmirror

That whole setup is badly engineered. I fought this belt squeal issue for months before finally getting it all sorted out. It's still going to give problems cause it isn't designed well, but part of the joy of the 968.

Paul Waterloo

Sometimes it's better to be lucky vs. good.

After the repair, the belt loosened up again as it started squealing with the AC on....I thought that was odd. Was on vacation for a week, and dove back into this morning (helps that I was in Europe, and I woke up at 4:30 AM).

I figured I would have to drop the belly pan to tighten the tensioner.....low and behold I find another (albeit different) large bolt sitting on the belly pan! WTF? Where did this one come from?

It ended up that it was the top AC compressor mount bolt that had walked out....I bet it was already out quite a bit before. It took me a while to figure out how to get it started again, then I realized that there are only two bolts holding the compressor on, one on top and one on the bottom. I thought there were two on the top. Once I figured that out, I could move the compressor where I wanted to and get it started.

When I was done, I also found the flat and lock washer that were on that bolt (they fell down onto the garage floor during the repair).....was wondering where they came from, as I added a lock washer to the bolt out of the parts drawer. LOL.

Once again, world balance is restored in the 968 world.

docmirror

I reamed out the two top bolt holes, then threaded them and put a larger bolt in. Since the casing is so close, it's very hard to do. Once you get the top bolts in, and modestly snug with lock washers(the back one needs to be ground a bit to fit the AC casing), then you can put the tension asm on and get it tight from the tension arm. Then the fun begins, trying to get back up to the top bolts, and get some combo of wrenches, 6pt socket swivel, extensions, etc so that you can finally get the top bolts tight. The rear one backed out again after that, and finally I coated it with a good glob of locktight, and fought it up in there. That sucker is NOT coming out again. What a carve up design.

MB968

Definitely good candidates for loctite. The front one on mine was broken when I first got the car. One advantage of pulling the engine to do the seals, was that I found a few other issues like this. And the rear bold hole had been stripped and had a thru bolt and nut. That nut was a real B to work with. Used a helicoil in the rear to repair. Now I'm wondering if I used loctite. Since I've now seen several posts about problems in this area, thinking I should probably check to see if mine are still tight. Been about 2 yrs since the repairs.

Paul Waterloo

I've had issues with this upper bolt coming loose. The AC compressor started making noise after my track event....and the belt loosened up. I tightened the bolt up about 1/2 turn and all was good again.

How many bolts hold the top of the compressor in? Just one?

Based on this picture, it looks like one, but I'm not sure.

Maybe I have to loosen the belt tensioner, then probably loosen the upper and lower bolt, install locktite, then tension the tensioner back up. I think the first time I tensioned the tensioner (only time), the upper bolt on the AC compressor was already loose.

mel_t_vin

Paul, is it your photo [#4], or does it appear the compressor belt was starting to fray on the lower span?

Paul Waterloo

The compressor belt is starting to fray. I have new one, and I was going to put it in, but then I couldn't get the PS pump tensioner loose, and I have since purchased a replacement tensioner, so next time I go in there, I could replace both belts.

I will probably defer doing the timing belt service until fall, I have all the parts for it and wanted to wait until then to replace the belts.

There is some kind of mis-alignment going on IMO.

MB968

The picture shown above is not the one in the 968 parts catalog which shows only one tab on the bottom, and two on the top. The tabs on the top are the attachment tabs. Each is tapped for a bolt. The front bolt is not the same size as the rear, but one size larger, if memory serves, an 8 in the rear, and a 10 in the front.

mel_t_vin

Are you sure? It appears the compressor manifold is oriented correctly, toward 12:00.

From my understanding, if it were flipped, with the manifold toward 6:00, the compressor would not function properly.

MB968

Allen, think you are correct. Went back and looked at the parts catalog. Been in there enough and knew that picture didn't look right, that's why I thought it was upside down. But, it isn't actually the correct pic for the 968. See my edit of the post above.

MB968

Paul, looking at the actual pics of your car I can't tell if you have two tabs on the top or not. But, you should have two on the top where the compressor bolts up to the large aluminum casting that bolts to the side of the block, part #56 Check out page 247 of the pdf parts manual for the 968, illustration 813-15. Parts 45 & 47 are the two bolts that hold the compressor on.

Paul Waterloo

Thanks for the help everyone....I only have one bolt on the top, no wonder the thing keeps loosening up.

I have only the front upper bolt on the compressor, will have to put in a rear. Will just take the belt off and replace it at the same time.

Question: Is sleeve "55" required for the rear AC compressor bolt? If the bolt fell out, did the sleeve also most likely fall out?