hey guys i need to pick your brains

well since i put in the 411 gears in i am finally able to use 5th gear and drive on the free way, however now i notice arounf 70 i get a vibration in the driveline,

i can feel in in the whole dcar but when i hold the shifter it is strong.

i think it could be the following, but would like your opinion

#1 driveshaft needs balanced

#2 something wrong in the transmission

#3 i know the t 5 is pressing against the trans tunnel could this cause a vibration.


it is not a high rpm vibration just a high speed vibration

if i am in 4th and hit 70 it is the same as if i am in 5th and hit 70,

the reason i notice it now is i went from 279 gears to 411 gears which obviously are turning everything faster now than before.

 

If RPM does not matter, then rear end ratio shouldn't matter either, right?

 

Chances are the driveshaft. Lots of guys in Foxes have swapped in gears to find the same issue. An aluminum driveshaft usually cleared the blues.

Also verify pinion angle.

 

I would say Drive shaft or possible tire balance problem.

 

What he said.

 

If there were no vibrations before, the I doubt it's the wheels or the tranny suddenly going south. Sounds like you're going to have to index the DS. Have fun since it's a pain to do it over and over again.

 

I'm going driveshaft too. When you removed it, did you note the orientation? It would be quick and easy to flip it on the pinion and see if things get better. If not, I'd have it balanced at Huntsville Driveshaft.

 

When they balance the driveshaft do they do the yoke and flange too? Each one separate or as a full assembly? Reason I ask is when I had the driveshaft made for the Z210 20+ years ago Lott didn't balance the yoke or flange and I had to go back and ask for those to be done separately. A nice balanced shaft doesn't do a lot with an out of balance flange or yoke.

 

I am having the same issue with my 85 but after clocking the driveshaft 3 times, it has removed about 75% of the vibration I was feeling. I am still going to swtch to a Alum-driveshaft this summer.

 

i am going to try to re clock the drive shaft tomorrow and see if i can get her up to over 100!