A.J. - 95 993

I dug into the rear of my little car tonight to take car of some squealing belts. They are loose, visibly wobbly when the motor is running. I jinxed myself by telling my wife "this should only take about a half hour". I have all the tools, I've done it before. No problem.

The first nut came off ok - 24mm box end wrench and a 10mm 12 point socket. I emphasize the 12 point, because the first time I changed my belts (and alternator) I used a Torx (6 point). That blunder added three hours to what turned out to be a 5 hour project: I stripped the shaft with the Torx. At that time, I couldn't find a 10mm 12 point socket, so I bought a set from Autozone

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That's when I found out that the shaft was stripped. I wound up tapping and threading the shaft, bottomed a bolt in it, loosened the nut, cut the bolt head off, removed the nut. But I digress.

The tool set above is too long, so I cut it off with my handy dandy Dremel. But I ran into trouble removing the 5mm allen bolts. (yes, they're removed in this photo)

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They were stuck, and I stripped what little material there was left in the head. I have a handy set of (plumbers?) Channel Locks that I barely was able to get on the head of the bolts and twist off. After applying liberal amounts of industrial lubricating spray. I took my wife's car to Home Depot, and was pleasantly shocked to find they had the (almost) same bolt. It didn't come out in the pic, but the label says
"CAP SCREW SOCKET
6mm x 30mm
6
PLAIN STEEL"

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The head is taller on these bolts, and just to be sure, I ground them down a bit. I may have gone a bit far, and likely created more work for myself getting them back off in the future. It might have been ok to use them as is. NOTE: I did use anti-seize on the bolts this time. I've learned to apply the stuff liberally on any bolt that I figure I may want to remove in the future. Including wheel lugs.

While I'm on the DIY topic, here's what my 12 pt tool and the pulley shims look like:

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Question - when removing a shim from between the two disks of a pulley, should you put those shims on the outside of the pulleys (assuming you remove an even number of shims) to maintain the overall spacing of the belts over the engine?

HarryD

Hi AJ,

While the cap screws will do in a pinch, you may want to see if you can find a supplier of "cheesehead" screws. They are like cap screws but not quite as high. Porsche seems to like to put them everywhere.

While I am no expert, if it were me, I would store the unused shims on the out side of the pulley so that I have them when I get a new (not stretched) belt.

A.J. - 95 993

Why is it the belts might have stretched? I don't drive it hard - I have to make a conscious effort to be sure it warms up each time I drive it. Short commute. Is it possible I had the belts too tight before? Is there a point of reference for the number of shims between pulleys? I did do as you mentioned - I left the shims on the outside of the pulley that I removed them from (both short belts needed tightening).

Ray Calvo

Too lazy to go to Robin's site and read my stripped bolt removal tips, eh? Well, serves you right!!!!

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Allen head bolt removal tips

If you have done any work on Porsches (and other German cars), you will notice that they are in love with Allen-headed bolts (and recently Torx-headed ones). I don't know what the reason is for this, but I suspect it is ease of robotics assembly with them.

Biggest problem I have noticed with these bolts is that after they have been in place for several years, and you have to remove something that has been out in the elements, the heads are fairly easy to strip. Not being careful about fully inserting the socket into the bolt, or cocking the socket as you apply torque will invariably strip them. Once they are stripped, now you are left with how to remove a stripped bolt that's cold welded itself in place.

First, to avoid (or at least minimize the problem), DON't use an Allen wrench or socket that has a rounded, worn end. Replace it, or you have a much higher chance of rounding the bolt head. Sears will (still) exchange a worn/broken hand tool for a brand-new one. As far as tools to use, would ONLY recommend high quality ones (Sears, Snappy, Snap-On, etc.) Also, don't use an Allen wrench/socket with a worn end; replace it.

If you do strip the bolt, I have found two possible ways to get out the stripped bolt:


A) BOLT HEAD CLEARLY ACCESSIBLE

I have used the following emergency fix for several of the above situations, including CV joint bolts on two different 911s and a brake caliper bracket on my Audi. This works for the smaller size Allen head bolts in my experience (up to approx. 8 mm hex). Get a good quality 6" pipe wrench (mine is by Ridgid); this small size will allow you to get into relatively tight areas. Wrap it around the bolt and pull up the slack. Now, whack the end of the wrench with a good size hammer. The wrench head will bite into the bolts and provide a good grip; the hammer will help shock the bolt loose.

B) BOLT HEAD NOT TOTALLY ACCESSIBLE

I found this method when I stripped the 6 MM bolt heads holding the seat in place; these are buried inside a U-channel, and you only have access to about a 30 degree arc on the bolt head. With a quality center punch and a heavy hammer, knock a centering kink in the center of the side of the bolt head (right angles to shaft, parallel to mounting surface). Now, while holding the center punch in the indented hole, move the punch head to the right slightly so that the punch is at an angle to the bolt head. Give the punch a sharp wrap with the hammer; if you're lucky, should be able to break the bolt free with a few tries.

On reassemble, recommend using a new bolt (even if you didn't strip the head) and coat
liberally with anti seize.

Much of the above should also be applicable to the newer Torx bolts.

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Also, to remove the large nut holding the pulley in place, I used a Allen head wrench and a large "knuckle buster" wrench. I think the next time I replace them I'll heed some of the advice on this board I've seen before to use Porsche tool 999 571 052 02.


RE your question: the answer is on page 13-33 of the shop manual. Open it and read it. If you haven't bought it, then buy it first.