Vibration after Tremec TKO install

[91notchbk]

Hi All, I just completed the install of a Tremec TKO on my 1991 Mustang. Now driving I have a vibration most noticable at between 65-70 mph.

I had the driveshaft balanced along with new u-joints installed. I also installed a new polyurethane motor mount and installed the h-pipe hanger bracket as well.


I am curious if anybody has had this same issue???

 

[1991vert]

do you still have the dogbone attached?

 

[91notchbk]

do you still have the dogbone attached?

I removed the dogbone a long time ago. This vibration was not present until after I installed the transmission.

 

[ShortThrow50]

your gonna have to undo your driveshaft at the diff and rotate it to the next set of bolt holes until you find the sweet spot. repeat until you find the right spot. the vibration will go away. i know it suck but its what you gotta do.

 

[91notchbk]

your gonna have to undo your driveshaft at the diff and rotate it to the next set of bolt holes until you find the sweet spot. repeat until you find the right spot. the vibration will go away. i know it suck but its what you gotta do.

I rotated 180 degrees on the yoke and it did not change the vibration.

 

[ShortThrow50]

I rotated 180 degrees on the yoke and it did not change the vibration.

i dont know then dude. sounds like a driveshaft issue to me. you mention that you had your driveshaft balanced at the same time. sounds fishy to me. maybe they didnt balance it to good. you should prolly by a new drive saft. get an aluminum one and you wont have that problem.

 

[91notchbk]

i dont know then dude. sounds like a driveshaft issue to me. you mention that you had your driveshaft balanced at the same time. sounds fishy to me. maybe they didnt balance it to good. you should prolly by a new drive saft. get an aluminum one and you wont have that problem.

I thought that too. But the driveshaft was balanced by a reputable shop that specializes in driveshafts and they have been in business for 30 years.

I was thinking it could possibly be incorrect pinion angle?

 

[Deleted member 87397]

Your pinion angle should not have changed unless that new mount you have for the tranny is seriously wrong. What you described so far usually ends up being a problem with the driveshaft. Most of the time you can just do the 180 rotation and fix the problem. I'm not sure what else the problem could be if the ds was balanced properly. Since you already did the 180 rotation I would suggest trying what was mentioned above and unhook the ds at the rear and move it to the next set of holes so you are not going completely 180 and see if one is better than the other. Also, do you know anyone with you could borrow an aftermarket aluminum drive shaft from before you invest in a new one?

 

[91notchbk]

Your pinion angle should not have changed unless that new mount you have for the tranny is seriously wrong. What you described so far usually ends up being a problem with the driveshaft. Most of the time you can just do the 180 rotation and fix the problem. I'm not sure what else the problem could be if the ds was balanced properly. Since you already did the 180 rotation I would suggest trying what was mentioned above and unhook the ds at the rear and move it to the next set of holes so you are not going completely 180 and see if one is better than the other. Also, do you know anyone with you could borrow an aftermarket aluminum drive shaft from before you invest in a new one?

I have some buddies that have driveshafts but they don't are not the 31 spline yoke.

It does seems like it is the shaft. I can try rotating to the next holes tonight. However, I am a little leary that this will help but I will try it anyway.

Here is a brief history of the driveshaft. I replaced the u-joints with Precision joints and installed the new yoke. I then sent it out to be balanced checked. Since it was recently balanced and I only changed the yoke and the u-joints I did not expect it to off. But it turned out a large weight was removed from the front and attaced to the rear along with an additional weight attached to the front. This was surprising to me because I did not expect a change. This situation kinda makes me suspect maybe the driveshaft was not balanced properly or maybe a u-joint is not right??? I have heard that Precision u-joints are not the best??

 

[91notchbk]

I just wanted to update you guys. I called the shop that balanced my driveshaft and they said to bring it back and they would recheck it. I did and it was out. So they rebalanced it at no cost. The shop apologized and said may be their machine was acting up that day??

Anway, after putting the shaft back in the vibration is gone.

Thanks for all the replies.

:SNSign:

 

[ShortThrow50]

awesome man. glad it worked out for you. now just enjoy that trans