Engine Vibration

I just recently installed a remanufactured Ford 3.8 SC long block in my 94 Thunderbird. The engine runs great except for a vibration from idle all the way up the power band, it is most notible in the shifter for the 5spd. I put a new pioneer balancer(auto zone) on the engine when we installed it. Has anyone run into problems of this type before? Also to note the new clutch is also from Ford and the flywheel was surfaced before installation. Any help would be appreciated.................John

Almost sounds like your driveshaft is out of balance.
Does it vary with rpm's and speed?



Also those autozone balancers are junk. I'd just keep it on in the meantime and look into a BHJ.

Vibrations

It has the same vibrations when sitting still and in neutral, so that eliminates the drive shaft and rear end....John

I would imagine you did new motor mounts at the same time, so that would be eliminated.

I'm curious if that Pioneer balancer is the correct one for the SC. I had not heard of another available balancer (damper) except for the Ford part and the BHJ damper. Did it come with a pulley or do you have the stock pulley or an aftermarket pulley?

The stock and BHJ dampers are neutrally balanced. If that Pioneer unit is not balanced, I'm sure it would cause the vibration.

Like the others have said. Check that balencer. I got my new one from Ford myself cause I heard about probs with others. Make sure you don't drive to much, because if it is your balencer you can wipe out the main bearings in a heartbeat.

Problem Solved

The problem turned out to be the balancer as everyone suspected. I had only run the engine about 30 miles to get exhaust work when we noticed the vibration, very noticable once your not running open exhaust. The autozone balancer was not balanced and infact had large amounts of weight on one side of the balancer, when I called and verified the p/n with autozone they said it was a match for what they called for but it is definitely not the right one. We reinstalled the old one till I can get a new one in from Ford and it was smooth as glass and its even tough to tell if its even running......Thanks for the help everyone, John

John: the stock balancer is lighter than the BHJ balancer.
Just thought I would point this out if your worried about weight.

Randy