well if it only vibrates at 60 with the clutch pushed in it cant be engine related. You may want to check your axle like port master said. It could also be a bent yoke on the rear differential. Is it making any noises and how bad is the vibration?

 

No noises. One thing I forgot, it still has the same vibration without the brake drums on. We have checked the yoke at the diff with a dial indicator, no problem. We have also checked the axles with a dial indicator. 60mph is just where the vibration starts. Ii just gets worse faster.

 

i have the same probablem, at the same speed. i dont have drums obviously but i replaced my rotors and pads and still have that same problem. i also know its not my engine mounts because when i installed my long tubes, i tightened them back down to spec. i was thinking its my driveshaft but you said you swapped yours out and nothing changed..

 

Do you still have the dogbone on the differential?

 

My uncle had a similar problem with his 92 hatch. After he changed his t5 to a tko600 there was a nasty vibration after 60. We checked and dialed everything but couldn't figure it out. Eventually he wound up putting a carbon fiber drive shaft and hasn't had a vibration since. Good luck!

 

i know u said u replaced the driveshaft but did u check the U joints? my car had the same vibration, it would make your skeleton shake if you held the shifter. all i did was check my U joints and sure enough they were about to grenade. swaped out the whole yoke, u joints, and driveshaft, with the ford racing aluminum one

 

Pull the driveshaft ount and check the U-Joints. You could have a bad one and that will sure cause the vibration. Also check the driveshaft for a missing balance weight. My money is on the joints. If you replace them do them both.

 

Sorry I was lagging behind you when I posted

 

No dog bone. Swapped the driveshaft with a different one out of a mustang that doesnt have the vibration problem. Didnt change anything.

 

Could the mph not have anything to do with my problem? I have only used that as a place to relate the issue to. Different rpm's dont change the vibration as long as the mph's are above 60. Thanks for any and all ideas. I will take anything I can get.