I have set the belts via the dial tool. But the balance shafts belt seems kind of loose. I understand that the balance shafts are a low load item but......I still can't convince myself that all is OK. What kind of deflection have you experienced? I have set the timing belt to 4.3 and the BSB to 3.

Thanks,

Paul <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

 

The specs are:

Timing belt (new) 4.0+-.3
B-Shaft (New) 3.5+-.5

T-Belt (old) 2.7+-.3
B-Shaft (old) 3.5+-.5

This is with the newer 18mm B-shaft belts. If you have the older style 15mm belts, then 2.7+-.3 for both new and old.

HTH!

 

I have set both the belts up by hand for years. On the 944, I always set the timing belt to about 45 degrees of twist for the longest run of belt. The balance shaft belts run loose, and I have always set them to just below 90 degrees of twist on the longest span.

Some people may not agree with this method, but once you have done a few of them, it is okay. You would be surprised at the number of shops doing it this way. At least it will give you a basis from which to check the tension of the two belts.

If you over tension the balance shaft belt, it will start to make a lot of noise.....the real reason it is set looser than the TB.

Remember, it the balance shaft belts comes off, it can get underneath the timing belt, causing it to lose drive, resulting in belt failure, and ultimately valve and piston damage. Better to set it a tad bit on the tight side, then back it off. Aslo, the belts will seat in over the first 100 or so miles, so it is always good to go back and re-check them.

 

I agree with John Kuhn - I don't think it is cost effective to buy a $500.00 Porsche special tool to do very periodic maintenance on a road car (borrow yes, buy no)

 

I agree also, 700 miles ago i installed new belts and also did them by hand...Well the timing had the automatic tentioner. But the balance shaft was by hand, It was set too tight and made noise so I re-did it and got it almost right the second time having very little noise. Now I need to retighten them as recomended at 1000 miles, I was thinking about taking it to a shop but now i feel better and will probably just repeat the procedure again.