ok so ive been chasing this vibration since i put the new motor and tranny into my maverick (351w+c4). the c4 is not the original from the car. before the swap i never had this problem. its a pulsing vibration that starts around 50mph and you feel it in the seat. the things i have done are: new u-joints front and rear, new drive shaft that i had checked and is balanced, i also had the u-joints checked that other day and the tech said if they were bad they would heat up pretty good and mine were cool from the whole day of driving. if you put the car into neutral the vibration goes away. the motor has the correct 28oz flywheel and harmonic balancer. if you leave it in neutral and rev the engine to the right rpm at highway speed its not there. so i believe its the tranny but everyone tells me that trannys don't make that kind of vibration. the other day while i was driving i saw a big cloud of white smoke out the rear of the car so i stopped and it smelled like buring tranny fluid so i took it back to my garage and the whole underneath of the car was shinny and had a very lighht coat of tranny fluid. which i believe means the rear seal blew out?? im not sure though. the tranny has been leaking since the day i got it, it drips by the mount, and from the bell housing. i was going tho get all new seals in the tranny and get it looked through again, should i bother with it?? is it the tranny making the vibration? im really out of possiblities so any help would be great.
you could have a worn bushing or something in the back of the tranny that caused your seal to blow out.
the only way to burn tranny fluid is through the vacuum line from the modulator valve. when I got my car it had a bad vib. I cghanged H. balancer timeing, u-jts etc. turns out it was in the tranny that was wallowed out. New tranny and it went away.
so if i have to get a new transmission case basically... do the guts of all c4 interchange? i was told this one is from the 60's i can get the numbers but i haven't pulled it yet.
Swap in a 71 or later C4 from a 250 six or V8. You don't want to try to use the weaker parts from a 60s C4 with a 351W.
