Sorry to be "posting up a storm" here, but i've got stuff to fix on my car and some questions on how to do it!
Since the v8 swap i've had a nasty vibration. Nothing special on the swap, a 302, c-4 combination. I'm pretty sure it's not the engine, as revving the engine in park produces no vibration (besides it's totally rebuilt, with a new harmonic balancer). However, i get a vibration at about 3,000 rpm in all gears...a bad, bad vibration (can't see in the rearview because it vibrates so badly!)!
Driveshaft is new, straight, and balanced. The original driveshaft for the tranny did NOT have a dampener on it, and neither does mine. Vibration is RPM based, not speed related (shifting into neutral makes it go away).
The transmission is rebuilt but i reused the torque converter, which is of questionable condition (it's 24 years old!) and i saw from a search that the torque converter was one of the things that caused a vibration on some other people's cars. Could be? I also get a pretty loud transmission whine, i suppose it could use a new pump if i get in there!

I don't know if it's related, but i also get a slight surging at lower rpms which does NOT change with the air/fuel ratio (tried all sortsa jets), and it seems like the first minute my car runs in the morning it's a lot "peppier"...i.e....does some nice burnouts! But once it warms up it won't hardly squeal 'em. It also does not vibrate until it gets warmed up.
I have some guesses, like a torque converter, but i'm not on as nice a budget as i would like and i hate throwing parts at it!
Thanks for looking and any suggestions you can offer would be great!

I've got this same problem, exactly as you described with my Mustang, 65 coupe 289. I've still got to check out the wheel bearings and the timing. I did mess with the timing after doing some work on the car and didn't have my timing light, so I timed it by ear...

Fred Fermin
72 Grabber 302

I've played around with the timing enough to know that's not the problem (new stock distributor, backed down total advance due to compression, set base timing to stock) and it doesn't seem to have affected the vibration at all. Of course, that doesn't rule it out in your case! I do have new wheel bearings though, and i don't think it's anything of that sort because it does it at 3 grand whether i'm in first at 20mph or 3rd at whatever mph. One thing i forgot to mention though, i do have the correct flexplate on mine so that can't be the problem...

not the safest thing in the world. But if you can successfully get the car in the air, fire it up and put it in drive, IF you can do this safely. Maybe you will see the source of vibration.

Hey guys,

I checked my wheel bearings on the Mustang and it seems that the driver side outer wheel bearing was a bit loose. I went ahead and changed and repacked it. Tightened in up per spec and the wheel has seem to tighen up.

I have yet to test drive it (I need to get it on the freeway).

I had just changed my bearings when I did a disc brake conversion earlier this year. I guess the race may have not been fully seated or something, causing the play.

May be worth double checking the wheel bearing anyway.

Good luck.

Fred Fermin
65 Mustang Coupe
72 Maverick Grabber 302

I did find something interesting on mine....i have a dead lifter. It's just one...an exhaust valve. I can hear the tapping while i'm driving. Could this cause a vibration?

I sorted out the wheel bearing issue and the vibration is still there. However I did come across this article

http://www.fordmuscle.com/archives/2000/06/vibrations/index.shtml

adressing some of our issues. I've still got to go through all of their suggestions.

good luck

Fred

Did you change anything on your rear suspension when you did the swap???Is your drive shaft Phased properly???( Try rotating it 180 deg.and re installing it) then test drive it.Could be a bad converter.Could be an improperly ground crank shaft.If you changed your rear axle/springs your pinion angle may be incorrect.Hope this helps.Good luck.

Transmission mount?

Well,,,if they didn't fix it in 5 years,,,,I'm thinking they got use to it!!!