[Qingdao]

So it dies off at different RPM ranges... now we have a clue.

I still think it could be CV axles, but if you are feeling it under rpm changes then its probably in the engine somewhere.

If it was me I'd find a quiet stretch of highway. Take the belt off and get it up to 80mph. See if your issues are gone.
^^just because that's easier than doing anything CV axle related.


I'd be willing to bet the reason you don't feel it in 1st through 4th is cause its such a low gearing.