Supercharged FC

iTrader: (7)

So I final braved the cold and pulled the trany out. Today I will pull the flywheel off after checking the end play today.

The clutch, trany mounts, and pilot bearing all look good.

The guys at the "beat" had this to say about bearing damage causing the vibration:

"A small spot of damage on a bearing would not cause a vibration. Only major damage would - and it would get worse FAST."

The plan is to put on a different S5 counterweight, inspect and replace the stationary gear if neccessary, and put it back together.

I should get it back together by next weekend and will post the results.

Thanks for your votes

Supercharged FC

iTrader: (7)

It hit a steamy 30F here today (that’s spring weather in Kzoo) so I got to work.

The end play is 0.002 inches by praying by hand (as the manual says) and 0.003 inches with a pry bar so the endplay is in spec. (.0016" - .0028" with 0.0035" max with wear)

I have the stationary gear out and the bearing looks fine, a minor dent from the threads on the eccentric shaft but nothing that would cause the vibration.

I will post pics of the bearing in a moment.

Supercharged FC

iTrader: (7)

here are the pictures


Here is the assembly


Here is a scratch on the engine side of the bearing (no raised material)


Here is a scratch on the outter side of the bearing, larger but still on raised material or signs of bearing deformation (flat spotting)


Zoomed out view


Zoomed out view

Supercharged FC

iTrader: (7)

So I decided the bearing was good, RB agreed

" The damage is minor. However, before you re-install the gear use a knife or similar sharp, straight tool and ensure that the damaged area does not "stand up" from the bearing surface, even if you have to cut a bit away."


I put it back together with an S6 (1993) rx7 counterweight, and after screwing around with a dead battery I got it on the road again.

NO Vibrations!!!!!!!!!!!!!!!

Hurray for me!

The counterweight was the issue. I think it was a old 13b or a weight that had been rebalanced for a race motor.

So for anyone with a weird vibration at 2000 rpm only, it could be your counterweight.


Thanks again for the replys