Hello,
I've been lurking a while picking up good stuff, thanks to all.I have a 67 200ci daily driver I'm restoring and it has avibration from the engine which has slowly been getting worse. It is amplified under load (driveshaft may be contributing), but the problem is in every gear at a certain RPM range (I don't have a tach yet but its smack in the middle). IOW, start out no vibe, hits mid band - vibration. If I leave it in gear and push to higher RPM's it almost goes away. If I let it shift - same thing all over again. It is very similar to U-joint vibration and I replaced those before I noticed the RPM link. I've done a complete tune (points, plugs, condenser, wires, cap, rotor) and timed it. I also checked the compression, thinking maybe a bad valve - all 145psi+- 5psi. It comes as a "throb" with higher vibrations inside (dont know if I explained that right). Is there a test for the vibration damper?Any other suggestions will be greatly appreciated! Its a fun car that makes my commute tolerable. TIA

 

Obviously under load vibrations are caused by worn U joints that you say have been replaced, and rear end gears, plus of course the tranny itself. I would suspect the tranny before the rear.

 

i wouldnt suspect the rear cause of the RPM connections cause the rear doesnt change RPM's when the trans shifts so i would think its either somthing with the engine of trans