Well after four years of haveing a down car I got mine back up and moving under its own power. In 2003 I had broke a pinion yoke, snapped a drive shaft, put a hole in the DS tunnel and busted the tailshaft housing on my T56. So after two deployemnts to Iraq I got her back up. I installed a Sixspeedsinc. 4B tranny, Strange Chrommoly DS and replaced the pinion yoke with a used unit from a member of this board.

Well I get the car up to speed at about 60 MPH and it starts to vibrate like the old TSB about the DS from years ago but worse. I am aware I might have flatspots on my tires from sitting so long but I would think it would do it constantly at every speed.

I do have a Spohn adj. Tq arm that might have been set up incorectly in the firstplace that cause the aforementioned mishap in 2003. When I reset it this time, I did the research and used the information from this site http://www.streetissuecustoms.com/pinionangle.html and when I set it the rear was up on ramps and the front tires were sitting on cynder blocks and it looked pretty level by eyeballing it. I check and rechecked the pinion angle several times.

I set it up for a -1* angle that was reccomended by doing a search on this site. Only thing different I did when measuring the transmission angle was I stuck the magnetic base of the angle finder on the output shaft of the transmission as I wasnt satisfied with putting it on the transmission seal.

The differential seems to have survived the chaos as the pinion is not loose and has no excessive play. It does whine a touch but it did that before the problems... The car is not lowered either.

I cant think that the new Strange shaft I have is out of balance. I am so paranoid of tearing anything else up. I want to fix this but I cant think of what it would be. I have a UMI stock style tq arm I borrowed off of a buddy to try to trouble shoot the drive line. I have to locate my stock tq arm mounts though and that might take some time...

Any help would be appreciated. Its been so long since I drove this car... and it feels good to have it at least halfway up again...

Thank guys,
Jeff

 

have the tires been re balanced? When i swaped a gear the vibs became very noticable. I got a ls1 ds and it helped some, then re balanced my tires and it was perfect.
Also all the havoc on the rear end is going to be tough to work out. I think thats responsible for some of the vibs too. good luck man, i wish i could help more

 

No the tires are going to get replaced soon. I know that should be the first thing to rule out but it just doesnt seem to me that that would be the problem, although I am sure the old tires are not helping things.

 

Well mine still has the vibrations. This is beginning to really **** me off. I also went and had the DS balanced and it was off. I think the DS balance helped some, but its still horrible. Well I can only think of two things left, tq arm angle ( I have checked and re-checked this) , or its in the rear end...
Its mostly on the decel. The tires are in a sorry state but this doesnt seem like tires...

Jeff

 

its probably your wheel bearings thats what happened to my car.

 

i took off my spohn torque arm and put my stock one on and it cleared up a lot of my vibration. i still have some though, but not as noticeable. and my rear end is a lot quieter with the stock torque arm.

 

I had the same results.

Well I took of the Spohn unit and put on a non-adjustable tranny mounted UMI arm. Things are a alot better. I still have some vibrations but its way better. I think anything else I have is in the tires. Combined with the rebalanced DS, the adj arm and some shotty tires would make some good vibes.

I havent really drove this car in soo long I dont know if I am expecting too much out of it or what. Part of it is the paranoia of braking more stuff. But I think I will be going with the UMI crossmember and selling my spohn unit.

When I get some new tires on I will post again.

Jeff