Earl Gillstrom

I am posting this because I have seen it twice in the last 2 weeks on '93 GTSs with the stock systems.

There is a washer in the stock cam belt tensioner system that is very easy to lose when assembling the stock tensioner system. It is 103-10 #32 in PET P/N 900 025 008 09.

With this washer missing, the cam belt could be extremely loose before you would see a cam belt tension light.

I normally check cam belt tension before I replace the belt. The light will come on at ~4.0 on the 9201. Proper tension is 5.0 to 5.3. These belts were 3.5 and 2.2 on the 9201. I don't know at what tension the cam belt fails (probably no one does), but these low tensions scare the hell out of me.

I usually "glue" the washer to the Guide Sleeve (#33) with grease or permatex #3 so it stays on during installation. It is very easy for the washer to fall off and roll under the car undetected.

It appears that you can probably get proper tension with the washer missing during installation, so everything seems OK, but I don't know if there is enough room on the bolt to allow subsequent re-tensions with the washer missing.

Rob Edwards

Mugshot of the offender:

SeanR

This washer has a bad habit of falling out, directly in to the pan you are using to catch the coolant, when you remove the roller arm.

Sometimes you don't even know it has fallen out, so you have to make sure you have it on reassembly.

rexpontius

One more reason why I really like the Pkensioner system :-)

Landseer

Earl do you know the washer thickness?

Bill Ball

How true this is. I can't tell you how many times I have found this washer missing. It falls to the ground as you pull the tensioner off to rebuild it, often unnoticed.

In a guide on how to do a timing belt job by one of our most esteemed members, you can see that washer is there at the beginning of the job and no longer there after the tensioner was reinstalled.

SeanR

I wondered if anyone else saw that. I was not going to be the one to point it out.

Earl Gillstrom

Earl do you know the washer thickness?
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Chris

That is a good question. I never measured a stock one and when one is missing I grab one from my junk bin. I will order some to have in stock.

Maybe one of our parts suppliers can measure one? P/N 900 025 008 09

Hilton

Anyone able to measure the thickness of this washer?

Its missing in my '87.

Hilton

Search-fu turned up the answer.

Its 2mm thick according to this thread here:

https://rennlist.com/forums/928-foru...uestion-2.html

borland

It's a washer used on several locations on the car. Load the PET and use the Acrobat search feature and part number to find other locations where you can temporarily pull the washer for measurement.

Hilton

I already found a shiny new one that is a suitable size (1.97mm thick, 10.6mm ID), but a quick search of PET per your excellent recommendation shows that the same washer is used in a few places.

For the benefit of others, the most accessible of the correct ones seem to be the 6x retaining studs on top of the front shock mounts in the engine bay, or the front and rear bolts that hold the AC compressor to its bracket.

The correct part is 20.7mm OD, 2mm thick, 10.6mm ID.

Landseer

Nice find / follow-up. I knew I'd seen that 2mm number somewhere. Looks like SteveG had posted it.

993turbo

Great info.
Have had the blet light coming on occacionally on my GT. Going to do a TB / WP etc soon, so will be interesting to see if the washer is in its place.

:-)

Earl Gillstrom

993 Turbo said:
Great info.
Have had the blet light coming on occacionally on my GT. Going to do a TB / WP etc soon, so will be interesting to see if the washer is in its place.

Keep in mind that the symptom is NO BELT WARNING when the washer is missing unless the belt is extremely loose.