84hotairgn
New Member
- Joined
- Oct 13, 2009
looking for some help or opinions on my vibration that starts around 70mph and gets worse with speed.first i should give a little history.bought this white 87 t off of craigslist in vegas early 2015.only test drove on surface streets so i never felt the vibration.has old school performance mods like ta49,bigger down pipe-brand unknown,42lb injectors,hooker cat back,etc.had an old len freeman sticker on the back window so i assume the trans was built by him,vigilante convertor,stage right trans brake.had alot of stuff i removed like vacum pump,fuel pump booster,etc.car runs good know and shifts fine.on jack stands with tires/drums removed vibration is there.drive shaft was rusty/original and i had the local drive shaft shop retube and balance the shaft-no change.noticed play at tail shaft bushing so i replaced it and when shaft was out i noticed witness marks on slip yoke where bushing rides.vibration is harmonic when on the gas and just a vibration when off the gas and shakes the whole car.after less than 100 miles the tail shaft bushing is eaten down to copper in spots and worn.since the drive shaft has been balanced/replaced and this is done with the yoke installed i suspected a problem inside the trans and had my local trans guy tear it down then i took the output shaft to a machine shop that put it in a lathe and said the most runout they found was .004 but there setup wasnt the greatest.the trans guy said he doesnt see anything else out of the ordinary except some worn clutches/steels.no twisted teeth on the output or yoke,and yoke diameter is in spec.
these marks are only on half to 3/4 of the yoke.visually i dont see that its bent.its fairly inexspensive to replace but i dont want to have the trans put back together and have the same problem. the ony other large rotating mass in the trans is the drum and i dont see anything indicating its bent or warped.any help would be appreciated.