bonus12

Vibration throughout rpm range
Made sure yesterday that I had the balance shafts aligned correctly, with the "O" on the woodruff key on the upper shaft and nothing on the woodruff key on the lower shaft.

I suppose it is not the mounts because the vibration is not just at idle. However, at idle, the engine is visibly vibrating.

Is it possible the alignment marks on the rear timing cover are off by one tooth in relation to the timing belt? Would the balance shafts being off by one tooth cause this vibration?

This began after a recent belt change.
Anything I should know about the rubber centered clutch? My clutch was replaced about 55,0000 miles ago.

Paulyy

well if the rear timing alignment marks are off then so will everything else.

Kerry Chadderton

I say balance shaft belt. It started after the belt change.

The rubber centered clutches make a knocking noise between gear changes, not really vibration. The engine mounts make more vibration at idle than anything. I doubt it's either of those. When my balance shaft belt broke the vibration was steady and throughout the RPM range. If you have the original belt covers on there you shouldn't have issues with timing marks.

Read Clark's Garage page on the procedure and do it again. Let us know what you find. GL

bonus12

The rare timing cover is most likely stock. It would be very unlikely that it had been changed. The upper shaft timing mark is at about 1pm, and the lower shaft timing mark is a raised tab as described in clark's garage, and it's at about 7pm. All looks good here. To be clear, I aligned the balance shafts to these marks perfectly, and made sure they weren't 180 degrees off.

Still, the problem is likely the balance shaft? I know it makes sense. However, if I went to do it again, i would have to purposefully misalign the shafts by a tooth. Right now, I am sure they are right on.

Has anyone heard of the balance shaft working smoother when aligned by one tooth to the right, or one tooth to the left?

mytrplseven

The Clarks manual states that the alignment won't necessarily be spot on so I quit worrying about that. My car runs smooth. When you did the belt, did you remove the balance sprockets? It appears that if your car was later than an 84, your post stated that you did the "O" orientation correctly (according to Clarks manual). Did this start immediately after doing the belt or after driving it for a little while. If it was immediately after then something was done wrong, but if it happened a bit later, then something in the belt tension slipped. Good luck

bonus12

I suppose I was just overreacting. There was some play in the shifter shaft; I fixed that. Turns out the clip for the shifter was missing, too. I'll get a new one of these soon. However, I drove 100 miles today in the 951...longest I've ever driven it. She was ready, but it took a long time to get her there. The vibration was not a problem at all...but maybe I still need new engine mounts.

Thanks for the help...my car's vibration is normal.