Driveline vibration under 60kmh

[oz_tom]

Appreciate any pointers on a vibration i'm getting through driveline which appears to be speed related. What should I chase next?

 

Car:

71 2002 with everything refreshed underneath within the last 1000kms. Stock 4 speed. E21 LSD.

 

Situation:

- Vibration through driveline at speeds up to ~60km/h. By 80km/h it's smooth.

- Doesn't matter what gear i'm in 

- Totally wore out the centre bearing within 1000km 

- Have since replaced centre bearing and rebalanced tailshaft - problem still remains.

- Also appears to be worse when car is cold. As car gets warmer, vibration is significantly less.

[uai]

What does rebalanced tailshaft mean? Does this mean you'Ve balanced the rear of the driveshaft without the front part?
(If yes: you can't do that - the whole assembly has to be balanced )

If the driveshaft is balanced properly and the cardanic joints are good and alignment is ok and the Guibos are good have a look at the driveshafts to the wheels.

[Dudeland]

Pictures always help.  Take some pics of the joints, the position of the LSD and the output of the transmission. 

 

Why did you feel you needed to "refresh" everything?  Did you replace the U joints? How are the motor mounts? 

 

I agree you need to balance the entire shaft.  Get yourself one of these angle meters like the one below and check the pinion angles. 

 

Or.... 

Take it to a driveline shop and have them do it.   

 

I am about to swap to an RX8 transmission, but I will take it to a driveline shop to sort out the driveshaft,  too much magic there for my skill set. 

 

Angle meter

 

503 - Service Unavailable Error

WWW.AMAZON.CA

 

 

 

Edited July 6 by Dudeland
Motor Mounts

[Mike Self]

I had a terrible driveline vibration on my 73, but at the upper end--between 55 and 65 mph (approx 85-110 kph).  Turned out to be a rear tranny mount that had turned to black goo and no longer supported the transmission at its nether end.  Replaced it with the much larger E21 mount and the vibes disappeared, never to return.  And that was in 1979.

 

Worth checking...just to take it off the list.

 

mike

[popovm]

Did the vibration start happening after the recent drivetrain work?
 

“Everything refreshed” equals new guibo?

 

If your center support bearing was trashed within 1000 km, maybe your guibo was too. Curious to know the current state of it and if it was aligned. Lots of threads here on either aligning just the guibo or the entire the driveshaft fore and aft. I was just researching this last night and found this great post from BillWilliams. https://www.bmw2002faq.com/forums/topic/76123-guibo-failure/?do=findComment&comment=428526