302 Vibrating - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

sum_weirdo · 12-14-2005, 19:18

I just finnished rebuilding the engine in my 83 Thunderbird a few weeks ago. And since then I've been getting vibrations that range in severity with no apparent cause. I get no warning lights but the vibration doesn't feel normal to me at all. I've tried tightening the mounts on the engine and the transmission, messing with the carburetor settings, retorqued the torque converter...I'm running out of possibilities. These are the changes I've made to the stock engine: 1) Mustang cam similar in characteristics to the HO roller cam, 2) E7TE heads from a 1990 Bronco, 3) B&M Holeshot 2400 converter and new stock flexplate, 4) GM style aftermarket HEI distributor running off a relay triggered by the old coil wire from the harness. The vibration is present in and out of gear and it randomly worsens to feel like a heavy thud, then it smooths out again to where it was. I don't feel it at higher rpms though. Anyone have any ideas?

AUXR8U · 12-14-2005, 23:08

Quote:

Originally Posted by sum_weirdo

I just finnished rebuilding the engine in my 83 Thunderbird a few weeks ago. And since then I've been getting vibrations that range in severity with no apparent cause. I get no warning lights but the vibration doesn't feel normal to me at all. I've tried tightening the mounts on the engine and the transmission, messing with the carburetor settings, retorqued the torque converter...I'm running out of possibilities. These are the changes I've made to the stock engine: 1) Mustang cam similar in characteristics to the HO roller cam, 2) E7TE heads from a 1990 Bronco, 3) B&M Holeshot 2400 converter and new stock flexplate, 4) GM style aftermarket HEI distributor running off a relay triggered by the old coil wire from the harness. The vibration is present in and out of gear and it randomly worsens to feel like a heavy thud, then it smooths out again to where it was. I don't feel it at higher rpms though. Anyone have any ideas?

Try your Harmonic Balancer

jas24zzk · 12-15-2005, 05:31

G'day,
had this with a muzzy here in Oz. Late model engine in early model car.
I see you have replaced the flexplate.
there are two. 28oz and 54oz (or it might be 24/58...but thats rather academic)

If you can, wind it round until you can compare the weight size of the weight on your current flex to the original. Being an 83, it should require the heaver flex.

Cheers
Jas

ZCFairlane · 12-15-2005, 20:16

Did you have the engine balalnced with the flywheel and Balancer?

Any mix and match on the cranks to use an earlier crank.

The information you have already from the other posters is good. You need to make sure you have the correct balancer for your crank and likewise the flexplate.

It must be one or the other or both.

Cheers

ZCF

sum_weirdo · 12-18-2005, 17:13

K I know what it is now. The power brake booster is leaking, sometimes when the pedal is depressed and sometimes when the pedal is down. It doesn't always appear when the car is just started and I can't hear it over the heater or radio so it's gone unnoticed until now. Is replacing the booster the only thing I can do?