I recently completed an LS swap into a third generation f body. Car runs great but I do have some vibration. Over the past week I've been doing online research concerning u joint working angles and basic drive train geometry.

I *think* that I have a basic understanding of what I need to do, however Id like to get some reassurance and or guidance from folks more experienced/knowledgable than myself.

From what I gather, I need to make the face of the pinion and the face of the transmission output vertically parallel to each other. Then tilt the face of the pinion towards the front of the car by 1 degree, or by whatever degree the car likes.

Am I on the right track?

 

Ur kinda on track. Vibration related to pinion angle is the result of stressed joints. So basically adjust to where u think ur close and drive. Right down what mph u start to feel vibes. Then go and and adjust one way without angle finder. Drive again. If vibrations started at 35 and now start at 45, keep adjusting that direction. Of its now 25 instead of 35, go the opposite way and just keep going. Make sense

 

We've found the Tremec app or the Spicer app to be a pretty good way to find the correct general range. We set the UMI cars with Tremec toolbox and they run 130 on road courses with no vibration.

-- Ramey

 

Tremec toolbox = sick!

I wish I had known about it before I dropped 75 on a digital angle finder. Thank you sir!

 

Yes, dead on.

 

wtf how has no one ever mentioned this app before. Or at least I never seen it. Downloaded it and can't wait to use it

 

Haha. Not sure. We've found the traditional "2 deg pinion angle" is just a starting point and the new smartphone apps really help get you in the ballpark pretty quickly. Good stuff.

 

I've been suggesting the app for years. Or the even easier method;
Measure the angle of your engine via the crank pullet or front surface of the head
Subtract 2* (Or 1* if using rod end control arms) from the engine angle
This will be the number you are looking for at the rear end.

So for example, if you measure the front crank pulley and get a measurement of 5* and you are running poly or rubber LCA bushings then you do the following: 5-2=3* So you simply set the rear end to 3* and you are done

 

do wut I think he would be better off listening to BMR.

 

I'm trying to make life simpler for him lol. For those who are visual learners:

 

well Yea but if there's still a vibe there than u find which direction makes it better and keep turning that way

 

Nope, you set it correctly and if there is still a vibe then you look elsewhere for the issue.

 

Thanks for confirming that.