Just finished installing a T5 transmission behind my 350 in my model a sedan. I took out a Muncie 319 3 speed. What i notice now is smoother running except when i switch into 4th or 5th on the highway i get some vibration. I did replace the universal. If i hold on and continue to accelerate in either situation or shift down it goes away ...its just on the initial gear change. No issues in lower gears under acceleration i just had the drive shaft shortened and balanced for the new application and did not notice this in the old set up. There is some angle between the transmission and rear end with the transmission slightly higher. Thoughts?
If the angles involved at trans and difdf are not opposing and equal you will get a vibration. I'm not up on how to do a sketch and post it, but basically the horiz centerline of trans output must be paralell, but one above the other in the vertical side view. If that doesn't make sense, I suggest a search for driveshaft and U joint angles, as I have seen sketches on this in previous threads..
just a few cheap washers under the tranny mount to get the drive shaft angle right and it is amazing what a change it made
I used the following digital angle gauge to get my transmission output and diff at equal and opposite angles. http://www.rockler.com/wixey-digita...7CAJ8qlIseevXT9Xz2LkPUDQqYOunZfNc4aAvdS8P8HAQ I've seen folks use the angle gauge with the dial on them like this one but I can't imagine it being very accurate. http://www.harborfreight.com/dial-gauge-angle-finder-34214.html
If you find all the angles are correct, check and see if the driveshaft is a little too short. That can cause a vibration also.
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