Ride Vibration

[catjim813]

All,has any one had their drive shaft balanced?  I am getting a slight vibration while driving, I recently had the drive shaft removed, my flex disks are ok and I am double checking the trans mount and carriage mount. My thought is to replace the U joints, carriage mount, trans mount and rebalance the shaft but I am not sure if I could make things worse.  I also checking my mounts on the exhaust for a possible issue as well.  Car was smooth before drive shaft was taken out.   69 280sl

[Tyler S]

Driveshaft vibrations are not very common on these cars but when removing and installing the driveshaft, It should have been marked and installed back in the same orientation it was removed. Especially where the two pieces spline together. Also make sure big spline nut is good and tight. Was there any other work done that could be causing the vibration? Brakes or wheels?

[catjim813]

Tyler,  no other worked was performed with brakes or wheels.   Is there a way to correct or to see if the orientation marks are aligned correctly?

[mbzse]

.../... Is there a way to correct or to see if the orientation marks are aligned correctly

See about this subject in these postings (reply#768 and others).
http://www.sl113.org/forums/index.php?topic=18284.msg144739#msg144739
Markings must be applied by self before separating
There are specialist vendors that have equipment to balance a complete drive shaft in bench environment
/Hans in Sweden

[chumps]

I had a vibration that felt like it was coming from the drive line at highway speeds. It was not a 'knock-you-off-your-set-vibration', but still a noticeable vibration. It turned out to be the centering cross had gone bad. It is the flange just behind the transmission with a three bolt connection. (#55 on the SLS driveline diagram). I replaced it and the vibration went away. Worth a look. Chumps

[catjim813]

Thanks Chumps,  was there any specific damage to this part that you could see where you knew it was bad?

[Tyler S]

catjim, The 3 mounting holes can start to get an oval shape to them over time, which makes the flange impossible to center. If your bolts went in nice and straight with no axial or side to side slop then its prob. ok. And to your previous question, No there are no factory marks present to indicate orientation. You would need to add them before removing the driveshaft, unless someone before you did. You may want to have another look and see if someone did mark it. And If they did, put it back with the marks lined up.

[chumps]

Catjim813 -  Do a search for 'centering flange' and you will find a good explanation of what was wrong with mine. The bolt holes didn't go bad, a lock ring inside broke. I was able to buy a good used one from a member. Chumps  Mark your drive shaft before disassembly!!

[catjim813]

Thanks Tyler and Chumps I will know for sure in the next two weeks what my true issues are.  I will replace U-joints and rebalance shaft, will keep all posted on results.