924Board.org

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

I just did my belts and front engine seals the other day, and noticed that my old balance shaft belt was quite narrower than the new one I put in. The new one was the same width as the Timing belt, but the old one was maybe .25 inch narrower. Why is this? Was someone being stupid or something?

88 924S 2.5L

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

The belt width was changed to improve the service life quite a long time ago.

What did you use to tension the timing and balance shaft belts?

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

I just used a belt tensioning tool that I bought with the poundages listed for that particular car. As the timing belt idler was self tensioning, I only had to tension the BSB. Quite simple. I have heard alot of people whine and moan about the job on this car but it wasnt really hard at all. The hardest part for me was getting the two crankshaft sprockets off because I did not have the right size puller, but I managed. (I removed the timing sprocket to replace the oil seal.) All sprockets on that car have TDC notches, so reassembly was relatively simple. The car runs like a dream.

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

So your engine has the spring tensioner for the timing belt...

And you used the spring tensioner to set the timing belt tension after you indexed it, then you ASSUMED that it set the correct tension without checking it?

You're a braver man than I am. I can't afford to take that chance, because I don't want to end up replacing some valves, or the cylinder head, or the engine block, if it turns out that the spring tensioner was caliberated wrong, or the spring stretched out as it aged (see the caliberation nut? You didn't turn it by accident when you were removing the timing belt or releasing the belt tensioner, did you?

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

Personally, mechanicals have never scared me, there is a certain point to which a person can use his judgment and take his chances. Problems can arise where you never suspect them, but if it looks good, runs good, then in my book its good. Since they are new belts I will tension test them within 1000 miles of installation, which is only a few miles away anyhow.

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

"...looks good, works good..." may work with other cars, and for other belts. Personally, on a 924S/944 engine, I require better than that, since the consequences of a loose belt are VERY EXPENSIVE.

Good Luck with that....

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

I am sure you are right. When I retension the belts, I will use my guage to verify if the spring tensioner is working right. If is is not I will certainly leave a descriptive post about it for you all.