rear drive train vibration

[weatherm]

I have a 1980 109 so it has the salsbury. I removed the driveshaft to replace the rear output seal on the tranny. I forgot to mark it before removal. As I recall I dont' remember having a vibration at speed. So now I have a vibration at speed that increases as the speed increases. The rear pinion is nice and tight along with the u-joints and greased. the only thing that has play is where it splines together.. not much but a tad bit of play. Is it off balance and is there a way to fix it or am I just paranoid? I put it in neutral and coast and its nice and quiet. This is so aggrevating.. I now have parabolics and some 30s on the rig but it still vibrates just as much as it did before I did the suspension and tire change.

[SalemRover]

Any chance you put the propshaft on backwards? I dont think that a new and tight rear propshaft would cause serious vibrations in either position. However a worn one may want to vibrate more in one orientation versus another. That aside I would check the transmission brake drum to make sure that is tight as well (best done with parking brake in the off position).


Good Luck!

-Jason

[weatherm]

nah the shaft is on right. Yeah the brake drum is nice and tight.

[kevkon]

When you removed the driveshaft did you inspect the u-joints?

[SalemRover]

Well then U-Joints would be good to inspect next. Good luck with it!

[I Leak Oil]

Did you torque the output flange down good and tight? Are the drive shaft securing bolts good and tight? Were the flange mounting surfaces good and clean before refitting the shaft? You didn't take the shaft itself apart right? Simply removing and refitting the driveshaft by itself shouldn't induce any vibrations where there were none before.

[greasyhandsagain]

Did you split the shart? Take the two parts apart and misalign the splines?

[weatherm]

Ujoints are fine and snug.. everything is tightened down.

We never separated the spline :(

I'm dumb founded

[greasyhandsagain]

Take the propshaft down again, and look at the mounting faces of the yoke. Part of the yoke is straight sided, and part of it is concave. Align the shaft back up in the positions that the old wear patina shows it HAD been aligned. Did you push in the bearing cups too tight on the ujoints (you did replace them right?). They shouldnt sit any further in than the depth of the circlip.

Just my thought on this. Good Luck.

[weatherm]

Ill check it out. I have never messed w/ the ujoints.. they are nice and solid.

[I Leak Oil]

You seem to be pretty confident that all the suggestions made are not the cause so if that's the case, it's time to chaulk it up to coincidence and start looking at other things that may be causing the vibrations. U-joints, wheel bearings, tire balance, loose axle drive flanges, loose pinion bearing, broken motor or tranny mount, etc. I think someone mentioned U-joints right? Sometimes they can feel fine by hand but under the stresses of driving can be proven to be bad. They are cheap and probably a good idea to change them when the shaft is out anyway.
Remove the rear shaft and drive it around. Is the problem there now? If so maybe it's in the front drive line. If not then you've atleast narrowed it down a little.

[weatherm]

Yep. Sounds like its time to do what you said. I'm guessing u-joint replacement is in the works for me. The vibration is definitely felt right down the middle towards the rear. Time to start ticking off the list....

[luckyjoe]

the only thing that has play is where it splines together.. not much but a tad bit of play.

My experience is that any spline play will cause vibration. It is only a question if you can hear/feel it.

Regards,