A quick check would be to remove the transmission, and throw out bearing, and start the engine and see if it still vibrates at low speeds.  The pressure plate should hold the clutch disc in place for this test if it is assembled correctly.  That would remove the transmission, drive shaft, and u-joints from the equasion, even though you say it vibrates in neutral.  Joe-JDC

JDC

,Just wondering here,  we pulled the heads from a 330 truck engine a few weeks ago to grind the valves. The pistons on the right bank were different than on the left bank. So just wondering if your engine may have pistons from an unmatched set, maybe even a forged piston in the bunch.

Will do. They were balanced as a unit because of the vibration, and then re-installed - no change, still had the vibration. I assumed they were installed correctly but I will check. Thanks.

I performed the  a change from Ford-O-Matic to a top loader 4-speed "big block 4-speed". Input shaft was the same length as a '56 ford 3-speed trans.
I did use a Mummert adapter when I did the T-5 Conversion. I had to build my on rear trans mount. Changed the drive shaft. I had  FEW TO CHOOSE FROM.
Now I had Vibration ................. Took the shaft to a drive line shop and had it straightened. Viola vibration gone.
However in your case even though the flywheel and clutch were "balanced"  This needs to be done as a unit. Both together, then they will be marked with an index mark. You must have both the clutch cover and the flywheel assembled "index marks"  coming together mark to mark.

You mentioned the vibration was apparent when the engine was revved while in neutral and sitting still.  I would check this before removing any of the input shaft on the tranny. You can check this by removing the inspection cover on the bell housing and check to see if the clutch and flywheel were installed "indexed".

Good luck!
Jim


  Jim Rowe Elkhorn, NE

If it vibrates with the clutch in and in gear, with the the input shaft not turning, then the input shaft is not a likely candidate.
Along with the other items you are checking, be sure and pull the flywheel and have the clutch/flywheel assembly checked for balance.

Looks like the next step is to pull the trans, replace the thrust bearing, and pilot bearing and check the input shaft. Thanks!

I had to shorten my input shaft a few thousands when installed my T-5 as it was hitting the crank. Input shafts vary in length Charlie is right, if it was hitting, you would not be able to get the car out gear. If you T-5 is vibrating it may be a bent input shaft, especially if it took out the pilot bearing? 

I love the smell of burning rubber in the morning!

I am contemplating installing a T-5 in my T-bird, and from what I have read on John Mummert's site, the driveshaft should be lengthned, not shortened.  Any Ford T-5 up to '94 should work as is, and not touch the crankshaft with his spacer kit.  Clutch plate should be changed to match the spline of the T-5, but throw out bearing and pressure plate is same.  What am I missing about your install?  Is it the pilot bearing or the throw out bearing that is worn?  Joe-JDC

JDC

I had the car into a shop a couple years ago (I haven't driven it much since then - just test runs when I try something else) to have the flywheel/clutch assembly balanced. When it was apart he checked the crankshaft end-play and found it to be a little more than normal - not too bad but more than normal. So he did a little investigating and found the thrust bearing worn. He had the trans out of the car and he didn't notice anything odd about how the trans was installed our any clearance issues. My guess is that the input shaft is right up against the end of the crank but not pushing hard on it. Maybe just enough to cause the two to be touching. I did not put the trans in, I had a hot rod shop put it in that has since gone under.

I don't see any unusual leaking under the car - just the drips I get from the rear main seal. Otherwise, nothing more than that. Starts and runs great, just vibrates.
Thanks.