SR71BLACKBIRD

I bought some parts from Sunset and had them throw in 3 belts for good measure. The belts on my 95 are original belts and still in good shape with 39K on them .

Should I change them or not and also if I change them is a Pulley upgrade neccessary if the original one is till holding up. Does everyone change to upgraded pulley when they change their belts or do they normally upgrade to the new pulley only if their belts have abnormal wear.

Also, I don't understand about the defective pulleys - do they explode because some people say they damage the hood when they do.

Also, on the belt change there is a special tool that one has to get from Porsche and I forgot to get that from Sunset Does Sears have something like that?

Thanks

JasonAndreas

The service interval for the belts is 30k miles so it is a good idea to replace them now.

The problem with the RS pulley upgrade is that the alternator will no longer supply enough power to the car while at idle. So for a daily-driver that sits in traffic you really have to think twice about this "upgrade."

The problem starts when people don't bother to tension the belts properly (they use their thumbs)...

You can go to Carquest, Napa, etc. and pickup the Gates "Timing Belt Tensioner" Part #91107 and a Triple Square.

ZombiePorsche44

As long as ya got em', ya might as well use em'................ditto to the rest of Jason's reply.

ZP44

SR71BLACKBIRD

I thought the Pulley upgrade was not the RS upgrade but a pulley that had less of an aggressive V-groove for better wear? Anyone know about this. Thanks

Scott

ppressle

Yes, There is a pulley upgrade other than the RS. I have it but have not yet installed it. From casual inspection, it appears very similar to the pulley already on the car...

I would also be interested in hearing if the pulley failure is anything other than a broken belt.

Pete

Robin 993DX

The new pulley update basically just integrate the two round dome washers as part of the pulley plate to prevent a belt slip problem. If you are not experiencing belt slip problem then it is entirely up to you to use the new pulley or not.

Here is a picture of the updated pulley


You will hear a loud squeal if the belt slips, if it continues to slip it will eventually heat up and burn up causing a lot of smoke.
My burnt up belt with the old pulley

JasonAndreas

Alternator - Belt Failure or Belt Noises
911
7/97a
1378
02/05/98
This Bulletin replaces bulletin, Group 1, # 7/97, dated 7-10-97.
New Alternator Pulley and Belt
Vehicle Type:
911 Carrera as of M.Y. 1995 and 911 Turbo as of M.Y. 1996
Model Year:
As of 1995 (S)
Concern:
In case of alternator belt failure or belt noises in conjunction with pulley, part number, 993 106 268 00 (s/s to 993 106 268 01), the alternator belt and pulley must be replaced.
Information:
911 Turbo:
When repairs are necessary, install only the new version belt and pulley halves.
Description Part Number

New belt (1 ea.) 999 192 372 50 (757 mm long)
Pulley halves (2 ea.) 993 106 268 01 (Yellow, chromated color) *
Shim (0.5 mm) 964 106 268 31 (as required)
Shim (0.7 mm) 964 106 268 32 (as required)
* The ratio of 2.68 to 1 remains unchanged.
911 Carrera:
The new version pulleys can also be installed on the 911 Carrera. However, the previous version belt must be used.
Description Part Number

Previous belt (1 ea.) 999 192 343 50 (760 mm long)
When installing the new version pulley halves on the 911 Carrera and Turbo, the distance spacer, (see arrow, illustration) is machined as part of the new version pulley and is no longer required. Because of this, it is no longer possible to store adjustment shims behind the distance spacer on the outside of the alternator pulley. Shims removed during the tensioning procedure should be stored in the vehicle tool kit. The tensioning procedure can be found in Repair Group 13, page 13-32.The new version pulleys can also be installed on the 911 Carrera. However, the previous version belt must be used.

SR71BLACKBIRD

Once in a while - I do hear a squeal - I thought I was hearing things though as it is very short and about once in a blue moon - this must be it.

Thanks guys- you're are the greatest.

Scott

96C4S

i went through three belts before updating the pulley no problem since

SR71BLACKBIRD

Is there a replacement tool that I could get instead of the Porsche one as it takes 4-5 weeks from Germany to get this: This is to stop the Alternator shaft from rotating while undoing the Alternator pulley I think?


Special Porsche 12 point allen tool part#999 571 052 02


Also, does the upgraded pulley fall into the category of If it aint broke you dont' fix it. ?

Thanks

ppressle

Jasons post above had a link that had lots of ideas
https://rennlist.com/forums/showthread.php?t=261207

Pete

Dudley

Stop by your local Napa. You can pickup the 12 point tool and belt tension gauge. All you will need.

Monique

I will be in Seattle monday evening. I could have picked up the part at Porsche Bonn.

Too late now.

SR71BLACKBIRD

Wouldn't you know it, I buy belts for the 993 which are still in good condition and last night I am driving my Diesel Van back home and hear a squeal and the smell of burnt rubber as I drive into the drive way. I prop open the hood and the Alternator belt is chewed to Sh..... and the A/C belts and Powersteering belts are all twisted because of being tangled with the Alternator belt. Yikes I am glad its not my 993 as rubber everywhere.

So this morning I had double duty to get new belts for my Diesel Daily driver and the 12 point and belt tensioner for the 993.

Thanks for all the great responses and links etc so far.

Dudely: I went to Napa and they had the Belts for my Van but they didn't stock the 12 point Allen Socket . They said that the tensioner needed to be ordered. I also went to Sears for the 12 Point and no luck although they said I should try Tool Town which I will try on Monday. Thanks

Jean Pierre - thanks its the thought that counts; that would have been cool!! BTW if you are in town this coming Monday and you have time, we should get together. A few of us Rennlisters go for coffee on a regular basis on the Eastside. rcwelch and c4sfan - are you guys around next week?
Any other Rennisters in the area interested? Jean Pierre, kindly PM me when you get in and if you are interested.

Scott

Monique

Arrive monday evening and leave tuesday 1500 or so.

Lunch anyone? My UK based GSM is +44 7970 889 279.

Send me an SMS or email... rcwelch has suggested a RL meet...

Noon is the only time for me I am afraid.