Pinion angle question/slight driveline vibration TKO 600

[XH29N0G]

I just had a TKO 600 put in where a 4 speed was before.  There is a very slight driveline vibration while cruising at 65-70 mph (worse on slight deceleration and down hill and better on acceleration).  I am wondering whether the pinion angle might be set incorrectly.  Is there any experience with this that might be shared?  I have 4.30 gears so things are spinning pretty fast.  I know there are other possibilities but the other parts are new, so I thought the pinion angle might be the first place to look.  Next for me would be the driveshaft.

Thanks

[68CoronetRT]

To check the pinion angle all you do is find a common spot where you can get an angle finder stuck on the tail of the trans(Flat surface) and under the 3rd member. They should be the same if not within like 2-3* I believe. All your trying to find is if the angle where the driveshaft leaves the trans is the same as when it arrives at the 3rd member.

Although this can be somewhat difficult if you dont have flat surfaces on both ends.

Do you have a custom driveshaft or is it stock? Maybe it's time for a custom build shaft? they are usually around 300-400$.

[ottawamerc]

I have been on here alot lately with a vibration issue with lots of good responses. Here's some. 

http://www.dodgecharger.com/forum/index.php/topic,102445.0.html

http://www.dodgecharger.com/forum/index.php/topic,103095.0.html

Plus MANY others if you search. Good luck!

Scott

[XH29N0G]

Thanks, both of you.  I missed one of those threads, but saw the other.  I too, had a driveshaft out of balance about a year ago.  This one is a new custom one made for this set up.  I am assuming they should have balanced it correctly - I did not do the install and would need to call to find out what company made and balanced the driveshaft, but I assume it is OK.  I will check the pinion angle.  It is good to know they should match.  I also need to do a bunch more tests, but this gives me a place to start.

[68CoronetRT]

My guess is the D shaft is out of balance. Think about it. The angle from the trans has to be the same because your bolting it to your OLD motor, and since the rear end didnt change, and the trans shouldn't have changed since the center shaft goes through the back of the OLD engine block.

This all makes sense in my head, hopefully it came out right

[XH29N0G]

The differential is the same and the motor should be in the same place, but the scatter shield, transmission, driveshaft, and u joints are all new.  I'll let you know how it turns out. 

[MSRacing89]

If you are feeling it more on Decel, then you are going to want to look at the Driveshaft balance.  Strong vibrations under load, look at the angles.

[XH29N0G]

Thanks.  It sounds like driveshaft balance is where I will check first then.  Is it common to get a new driveshaft that is slightly out of balance?  I do not have a sense of how exact the process is.

[MSRacing89]

Thanks.  It sounds like driveshaft balance is where I will check first then.  Is it common to get a new driveshaft that is slightly out of balance?  I do not have a sense of how exact the process is.

Sometimes local shops are hit and miss.  Just make sure he is spinning it at a solid RPM.  I remember see 2800rpm on the machine we used.  Also have him put a dial indicator on there and check the run-out for you.  I would say anything over 10 thou is a redo in my book.