help! vibration in drivetrain under acceleration
 

Would appreciate any help! I drive a '86 944 with manual trans and 2.5 non turbo. The trans was replaced after a '87 924 engine was installed. I wonder if the driveshaft could have been moved enough, during the trans exchange, where the driveshaft was pulled out of the pilot bearing. Or even I wonder if the pilot bearing was the same size in the 924 engine is the same size as the 944. It seems that my car has the drive shaft bearings at each end. Maybe that would prevent much movement. Is the rubber trans mount important enough that age would allow vibration? The vibration....... it occurs as I increase speed in the higher gears of 3rd and 4th, it's not major but very obvious to me and concerning. Thanks.

RE: help! vibration in drivetrain under acceleration
 

Ok, so the car has the 924 motor in it right now or the 944 motor? The 924 torque tube and the 944 torque tube have different part numbers, so i would imagine they are different to some degree. The torque tubes have 4 bearings in them. THe rubber tranny mount will definetly cause some vibration if it is worn. How long ago was the tranny replaced? I would check your CV bolts at the tranny end, and make sure they are all tight first, there are 24 of them. Could also be motor mounts starting to go.

RE: help! vibration in drivetrain under acceleration
 

Thanks for the info! The 924 engine is in the car now and the trans was replaced three years ago. The engine was put in one day and the trans the next. I wonder what a new trans mount looks like... maybe is can get to the dealership in the next while to see one first hand or one on a computer screen at least. Then again I do have a salvage yard a couple of hours away that i will be near to tomorrow. So i could see what they have that is newer than mine to get a look. Anyway i worry that the drive shaft is out of the pilot bearing. How could i check to see and know if this were the problem? Next, can the trans mount be replaced without removal of the trans? All of the CV bolts looked tight, i looked two days ago for anything that would be obvious.... . Do you know if there are different numbers on the pilot bearings between the '86 944 and the '87 924 engines?Thanks again

RE: help! vibration in drivetrain under acceleration
 

Ok, i just reread your first post. Since it was an 87 924, it had to be an S model, which used the same motor as the 86 NA, which would use the same torque tube. The driveshaft could not be out of the pilot bearing, or else the tranny would not have mated up (The two shafts are very close together when you put it all together)...it might be back a mm, but not far enough to not be in the pilot bearing. The mount would have to be replaced with dropping the tranny...not a hard job, i have done many by myself....you can rent a tranny jack for about 30 bucks and knock it out yourself in a few hours.....an extra set of hands is helpful though.