adding grease to a worn slip yoke
 

Last fall I replaced a rear u-joint. Upon removal of driveshaft, I noticed some leakage at trans tailshaft seal. There was also some slight pitting on slip yoke. The splines within the yoke did not appear to be mashed or worn enough to raise concern. I have driveline whirring (speed related) and a vibration between 30-35 mph. My questions are:

1.) would worn splines in a slip yoke (again, I didn't see anything that raised concern) lead to a vibration in floor shift handle, and steering wheel, at 30-35 mph?
2.) would worn splines contribute to whirring sound? I believe the yoke is a 1350 Spicer.
3.) Any risk to filling the spines with a heavy axle lube to see if it addresses whirring sound or vibration?

THANK FOR LOOKING AND HELP!

I'm going to start a diff thread on driveshaft phasing.

Re: adding grease to a worn slip yoke
 

It would be great to hear from a few of you. I have read numerous google articles and you tubes on people who have added grease to clunking slip yokes. Particularly in trucks built in last 10-15 years.
Just wondering if anyone has had a yoke problem; what were the symptoms; and, was there a quick fix or did you have to replace it??
Getting back to my thread, I just wondered if yoke problems and vibration go hand in hand.
Hope to hear from you.

Re: adding grease to a worn slip yoke
 

I am far from an authority, but I don't think sworn splines would whine. Wouldn't hurt much to coat it with some heavy grease and see, but sounds more like gear whine from being mis-aligned. Rear ends kinda howl it not set up properly.

The old where does it whine question is, if you feel it your seat, it is in the rear, if in your hands, it's in the front, or something like that.

Good luck and let us know what you discover.

Re: adding grease to a worn slip yoke
 

It can be motor or trans mounts, too. How's the driveshaft angle? What trans are you running?
Grease in the yoke splines might dampen for a while but I think would get washed out by the trans fluid.