TKX Post Swap RPM Related Vibration

[1970DCH]

I completed my TKX swap (I will post a more thorough write up in due time with my experience) but I have an RPM related vibration. I’m hoping someone here might have some input before I pull the transmission out to inspect the rotating assemblies. Basically, I have a vibration that gets worse the higher up the RPM I go. It is NOT speed related and in fact, very smooth at all speeds at lower RPM, ruling out driveshaft issues or pinion angle issues.

Has anyone experienced this using a kit from SST? My engine is an internally balanced engine and the related parts are correctly 0 balance for my application. I’m kicking myself to not have checked the parts, but instructions did not mention that I needed to do this.

Is there a way I can test/ rule things out?
- I’ve confirmed that nothing is hitting anywhere.
- I’ve confirmed that it is not speed related, but RPM related.
- I had triple checked my runout calculation
- I had triple checked that my pilot bearing was seated properly.
- everything torqued properly.
- no issues with installing the transmission to the bell housing.
- my engine is firing on all cylinders.
- there is no clutch slippage or juddering.

- Am I just dealing with a faulty flywheel/ pressure plate, most likely? I’m pretty disappointed to have to pull it all out at this point…

 

[PurpleBeeper]

It sure sounds like your flywheel/pressure plate isn’t balanced

 

[furious70]

Was the engine running without issue with a different transmission?

 

[1970DCH]

Was the engine running without issue with a different transmission?

Yes; it had a 904 and there was no vibration at all.

 

[1 Wild R/T]

If it is in the flywheel/clutch you should be able to duplicate it sitting still... Trans in neutral bring the engine RPM's up... Does it vibrate?

Everything in the trans spins except the output shaft.... The input, the counter shaft, all the speed gears... Everything... Along with the clutch & flywheel...

 

[Charlie Brown]

Two suggestions - 1) - call SST, 2) - recheck pinion angle. When I did my TKX conversion, I had a slight vibration which I traced back to my pinion angle. I only had to correct the angle 2 degrees, but that made the difference.

 

[1970DCH]

If it is in the flywheel/clutch you should be able to duplicate it sitting still... Trans in neutral bring the engine RPM's up... Does it vibrate?

Everything in the trans spins except the output shaft.... The input, the counter shaft, all the speed gears... Everything... Along with the clutch & flywheel...

In neutral it is still there. I did just read that if I do this test in gear with clutch disengaged (and if it still vibrates), then it rules out the clutch and transmission, leaving the flywheel and PP.

 

[1970DCH]

Two suggestions - 1) - call SST, 2) - recheck pinion angle. When I did my TKX conversion, I had a slight vibration which I traced back to my pinion angle. I only had to correct the angle 2 degrees, but that made the difference.

Yes, I have been in contact with them, running through some variables. On the pinion angle, I did check that and needed to adjust by 2 degrees, but the vibration isn’t movement/ road speed related, it’s tied to RPM. It’s looking more and more like out of balance flywheel/ PP.

 

[1 Wild R/T]

Sounds like you have it pinpointed pretty well.... Now ya just gotta find the time/motivation to fix it....

 

[1970DCH]

Sounds like you have it pinpointed pretty well.... Now ya just gotta find the time/motivation to fix it....

Right…definitely disappointed; what I’ve learned is that even if the components are said* to be zero balance from the factory, you should still confirm if not specifically confirmed from the factory.

 

[dodgeboy440]

Right…definitely disappointed; what I’ve learned is that even if the components are said* to be zero balance from the factory, you should still confirm if not specifically confirmed from the factory.

Right…definitely disappointed; what I’ve learned is that even if the components are said* to be zero balance from the factory, you should still confirm if not specifically confirmed from the factory.

Right…definitely disappointed; what I’ve learned is that even if the components are said* to be zero balance from the factory, you should still confirm if not specifically confirmed from the factory.

I’ve always made it a habit to check flywheel balance on everything before the intstall..

In neutral it is still there. I did just read that if I do this test in gear with clutch disengaged (and if it still vibrates), then it rules out the clutch and transmission, leaving the flywheel and PP.ive