Foxman

I'm guessing the alternator as well - tightening the belt may have forced it to turn a bit better, but the problem is still there.

nile13

Looking at pulleys, can't quite tell if it' new or old design.

I threw an Autozone belt on it, that's all I could find at 9PM. The belt is 10x760, though it could very well be 9.5 wide, I've seen both while researching.

As many here said, I think it might be an alternator issue. However, I'm a bit surprised that I don't feel resistance or hear a noise when spinning alternator shaft by hand. I'm also really surprised at all the smoke and heat when installing the belt with two shims. It felt like it was tensioned fine, but it's hard to tell without Kriket tool or finely tuned experienced fingers.

Will try it for a few days, see how it goes. If it needs a new alternator, it'll get a new alternator.

AOW162435

Old version:




New version:




My version:






Andreas

nile13

Thanks, Andreas!

Fairly sure that I have the old version, as that thing/spacer under the nut comes off and is a separate part. I think in the new version it's an integral part of the outer pulley half?

Should I upgrade? If so, both halves or just the outer?

nile13

Anyone with info on the bolt size for A/C compressor bolt nearest to teh middle of teh car (left far side, looking from the back of the car)?

And the size or part number of square nut for the other three bolts?

Also, has anyone used VIM XZN110 tool for a triple square? Does it fit in there with a ratchet?

nile13

To answer my own question, i appears that the small bot is M8x14 (p/n 900 075 323 02) and the nut is M8 with, what I assume, 1.25 thread (p/n 964 126 311 00)

kjr914

If you have: nut, outer spacer, pulley half, shims, 2nd pulley half, 2nd spacer.....then you have the old one. Porsche did an upgrade, but I don't recall the reason. Some here run them just fine, just as your car has done up until now... But if you are **** retentive, you can always order the new parts and swap (saving the original for those future Concours nut jobs with early 993s.... )

You definitely have failing bearings, since the heated pulley means a slipping belt. Only way to slip is be either super loose (much greater than 1/2" of belt deflection in the middle with your finger. I run them at about 1/2" deflection normally with no issues.), or have a sticking bearing. You don't seem to have a loose belt, so I'm going with bearing. It probably turns freely without any tension pulling down on it, but when the belt is on an loading the alternator shaft, it pulls downward and you can't provide that kind of force testing it by hand.

VIM XZN110:
https://www.amazon.com/Vim-XZN110-Tr.../dp/B002YKJI34

Snap-On Bluepoint version:
https://store.snapon.com/Triple-Squa...m-P646948.aspx

I know the Snap-On one works well and have used it for years. It is a stubby and with a 3/8 drive, fits behind the alternator shaft. The XZN110 looks to be slightly longer, but I can't recall how tight it is getting socket and driver behind the shaft end. Given the same cost (about $9.50 now), I'd just order the Snap-On.

NC TRACKRAT

New version pulley mod requires 2 ea. 993-106-268-01. For other than Turbo, use the same belt 9.5x760.

GC96

That's what I use when I do the belts on my car.

GC

nile13

Thanks, guys!

Keith, I think you're spot-on with the idea that belt pulls down on the shaft and causes the bearing that already has some play in it to let the shaft deflect. Sounds like it might be the new alternator time. We did put an Autozone rebuilt alternator in 4 years ago (in a pinch, that's what was available). It has a lifetime warranty so I'm thinking whether to go with them again or get something else.

Good find on Snap-on and free shipping I'll probably order that instead of VIM as it seems more stubby and should be a little easier to maneuver in. The only question is it 3/8th or 1/4 drive? The site seem to indicate 1/4. Could you please double-check yours?

BobbyT

During a 993 tech session at Callas Rennsport in 2004, Tony said that the original alternator pulley halves can break, and resulting shrapnel can dent the engine lid. I'll bet that is an exciting experience, but my ticket has already been punched sufficiently in that category, so I changed the pulleys.

+993 to the comments about the importance of using genuine Porsche belts.

kjr914

Definitely 3/8". The text of the description is wrong ("1/4"), but if you look at that "path" on the website, it says:
And I double checked in the garage.

nile13

Thanks again! Will order Snap-on triple square to keep in the car.

nile13

Hmmm.... so here's another mystery. Should the alternator belt be 10 x 760 or 10 x 775? I believe that quick try of 775mm length was too long Had to put on 760mm belt and remove shims. However, pretty much every catalog, including Pelican, shows a 760mm belt for the alternator. The PET shows... both. The old OEM belt was 10 x 760 as far as I can read on it.

What's going on here and what am I missing?

NC TRACKRAT

9.5x760 is the required belt for anything other than a Turbo.