PorscheDude1

Hi, I am in the process of doing my timing and cam belts for the first time on a 87 944 N/A. Bought new belt and rollers. My problem is a bad viberation at 3500 RPM in neutral. I have just replaced the motor mounts with new turbo mounts 100 miles ago. I suspect a balance shaft belt has skipped a tooth. I looked on clarks garage and am cofussed about balance shaft alignment. Any help or sugestions would be greatly apprceiated.
Thanks and Happy New Year!
John

944_S_TYPE

Hi john. I just did the shafts on my 944S. If you clean and look closely at the rollers there shouls be an notch or a little triangle on the engine side. Once the engine is in TDC(1) . match that notch up to the notch/ molded allignment mark on the belt cover plastic casing,
good luck.

PorscheDude1

Is it fool proof in that i can not be 180 Deg. out? Just curious.
Thanks for the quick reply!

hosrom_951

If you take off the rollers, it's a good time to do the seals as well. Just make sure that when installing the rollers (balance shaft) that the wooddruff keys are facing upwards, and the 'O' (for top balance shaft) and 'U' (for lower balance shaft) are on the key, then alighn them to the marks located on the rear timing belt cover.

If you need any diagrams of this, PM me.

Porsche-O-Phile

Depending on the year of your car, the lower balance shaft may or may not have the "U" marking (this was only on '83 and '84 models, IIRC). On others there is no mark displayed in the lower shaft pulley window when it is properly oriented. Check Clarks Garage procedure "ENG-08" - there's a rather excellent write-up there with description of this nuance there.

pete944

Your lower shaft is probably 180 degrees out. The sprockets have 2 keyways. If you use the wrong one it will ahve a nasty vibration from 3200rpm and up.
The 'O' marking on the flange should be partially visible through the rectangular hole IIRC.
www.clarks-garage.com has a good write up on this.

joseph mitro

pete beat me to referring you to clarks garage. excellent source of help. good diagrams. that website is the one i used to install my balance shaft rollers and belts and the engine is smooth as silk.

EDIt - i forgot.....i have a few pics on my 944S "rebuilt" site that shows the orientation of the balance shaft rollers and how they go on. IIRC, the engine should be at TDC #1 when you install the balance belts, aligning the rollers to the notch as described above. click on the link in my signature.

good luck

PorscheDude1

Thanks guys for the quick and helpful replies!
John