Hi! i have a 92 camaro i put a 400 ci. 30 over in place of my 355 the 400 is fresh but i am having a very bad vibration issue, when the trans is out its as smooth as a caddie but when i put the trans back in (1981 t-10 fresh) it is smoother for a half mile and then starts wobbling. I changed the balancer i took the trans out changed the pilot bushing no difference,i took the cluch off started it it was as smooth as ice, put the clutch on it still was smooth,i put the trans on and take it for a ride it starts wobblingi take the trans back out it is smooth put it back in its smooth for a short time an develops a wobble.ive been through h*ll and if anyone could came across a problem like this please let me know what you did to repair it thanks. Elie

 

what's the play on the input shaft lookin' like? any side to side? i have no experience with 400's or standards, but it's a thought.

you running the correct externally balanced flywheel for that 400?

 

Maybe it's more then just transmission.... Maybe it's driveline wobble? Maybe try runing it with just trans and no driveline?

 

that could make sense too, like a bent ds or axle, maybe even something as retarded as a loose lug nut

 

To start off, if the car is together take it down the road till it starts
a-shak-in. Push the clutch in, if it stops it's not in the drive shaft
and back.

 

whats up guys! i am using the proper externaly balanced flywheel and balancer both new. The tranz is rebuilt with new bearings and syncros.if i hold the clutch down put it in gear and not move while revving it shakes in nutral while not moving it also shakes. i actually did a test where i took everything off started the motor with just the flywheel and it ran GREAT! then i put the clutch on the flywheel and started it and it also ran smooth and GREAT! then i put a new pilot bushing very carefully and straight in then the bellhousing and tranz and driveshaft NO crossmember or exhaust, it ran smooth and great..........But of course when i put the crossmember and exhaust up and then start it it wobbles.. The crossmember was used in the same car for years as well as the trans and exhaust i have never had this kind of problem or even any sort of vibration with any of the 4 motors that i have had in this vehicle with the same exact driveline and exhaustand mounts and bolts ext. everything is 100% brand new and has also been replaced for testing purposes (balancer and flywheel) i had the trans in and out 4 times in two days repeating the test and got the same exact result as last. THE ONLY thing i have not tried yet is running open headers witch i will do after Christmas.... thaks alot for replying and have a very Merry Christmas. Elie

 

What Bell housing are you using?

1st does the t 10 front bearing retainer snuggly fit the bell housing?

If not its the wrong housing. The trans is centered on the pilot bearing and the bell housing.

2nd was the bell housing hole centered to the crankshaft with a dial indicator?
If not and off cent it could explain your troubles.

 

Hey! I have the mcloud hydrolic throwout bearingand the ring that snuggly fit into the bell housing i have never check for center of bellhousing witch is stupid off me BUT when i take my exhaust off all shaking stops.......i have hooker super comps ceramics pretty nice 2 1/2 Y pipe and 3 inch cat back with 2 chamber flowmaster i never seen this problem before..thanks for replying Elie