i have a problem after i convert to rolla 70 rack.. when i left of the trotel/pedal the car seem vibrate it happen just about a week ago.. it cause of the..

1.gearbox
2.engine has been adjust abit high
3.or the copling broken hmmm or the agnle of shaft not correct hmmm



what sould i do i plan to change the whole new shaft but afraid if the things happen again hmm..

First off, check the bolts connecting the tailshaft to the diff are tight, mine weren't tight enough once & i got similar problems. If this isn't the problem, & you're already under the car, pull the tailshaft out & check the universal joints. They should move freely, no binding or tightness. If they're worn, replace them, if not, then start looking for any thing else that you might not have tighten enough, just do a spanner check over all the bolts. Once you know everything is tight & the uni's not worn, then check that the engine isn't crooked in the engine bay, or that it's leaning too far back or forward. the engine & transmission is supposed to be square in the car,even if it's offset one way or the other, & even with the ground. You might have to modify some of the brackets to get the motor correct.

ok thanks for that will check it 1st

Hmm, that could be the cause of my vibrating issues I have around 80kph? other huge factor could be unbalanced\ out of round wheels and tyres?

LDO, if the vibrations go away after about 85-90 k's, the most likely problem is wheel balance. If they come back at 160 kph, then you know it's wheel balance, though don't take this as permission to try & check. Look for evidence that a wheel weight is missing, they usually leave outlines on the rim. Dattosans problem happens when he unloads the drivetrain, thats why I suggested looking for loose nuts first. It took a long time for me to live down the shame, when it happened to me, mainly because I was stressing out about the uni's I'd just replaced being duds. None of my friends let me forget about it for a long time, until one of them did something stupid & it was his turn to suffer.