Lubing propeller shaft Risky (AKA Drive Shaft)

[2001LC]

I am trying to do basic drive shaft maintenance on my 2004 LX470.
I have read the "official clunk thread" and a bunch of other posts about proper maintenance of our "drive shafts" and i think i understand the basics but there are still a couple of things im not perfectly clear on.

Here is what i think i understand... If i get an NGLI #2 lithium based grease i can use that in the Spiders and Slide Yoke. If i wanted to go the extra mile i could get a second grease gun and grease the Slide Yoke with a moly fortified grease for extra protection but this is not required and i should not use the moly fortified Grease in the spiders because that could cause damage. If i run into trouble and grease doesn't seem to be moving past the seals i can up the interval and use the lighter more viscous NGLI #1 grease until it frees up any clogged old grease and i can switch back to NGLI #2

If this seems right ill go get under my rig and start pumping. Any advice or correction would be greatly appreciated.

Thanks!!

You've got a very good handle on it. I'd add the moly helps reduce stiction in slip yoke, not something we see much of.

 

[Verybadwizard]

Thank you guys for the comments! Looks like im on the right track. Ill get down there today and get it done.

 

[2001LC]

Tip: Always wipe dirt from tip of grease fitting (zerk) before beginning.

 

[Verybadwizard]

Thanks for the tip. I cleaned the zerks and pumped the grease in. Everything went as expected on the spiders but the slide yoke i did quite a bit of pumping and nothing came past the seal. Then on the rear slide yoke i realized it was beginning to extend the slide yoke. What is the best way to avoid blowing the seal outright or is that even a concern? should i try pumping a more viscous grease?

Thanks again!

Just for info sake here is the grease i used. (Amazon.com: Mobil 1 Synthetic Grease: Automotive)

 

[ewrk1989]

After pumping grease I always remove the zerk and drive around the neighborhood over a couple bumps. Then come home and replace the zerk. This should allow any excess pressure to dissipate. It will push out any excess grease through the hole where the zerk goes.

If you take a close look at the construction of the drive shaft / propeller shaft, the slide yoke has the female splines. Putting grease in the zerk means that the small cavity in the slide yoke must fill up, then grease will be forced through the splines, and then into a cavity on the male end of the driveshaft, which is covered by a dust cover. Lastly, it will come out the seal of the dust cover if it can.

Therefore, if you have pumped in so much grease that the yoke is extending, you have DEFINITELY pushed plenty of grease into the fitting, through the splines, and are now filling the cavity inside the dust cover. You have more than done your job at this point!

This assumes that your splines are not totally filled with gunk.

 

[2001LC]

Here's a trick that recently worked for me. Raise rear of vehicle allowing differential to drop extending P. Shaft revealing silver on slip yoke Wipe the seal clean, then wipe on some new grease on silver of slip yoke and the seals' lip rubbing it in. This primes outer lip of seal. Then put vehicle back on ground (neutral position). Pump in grease until you see yoke just start to extend putting pressure on transfer case & differential. Then give one more pump which will extend yoke just a bit more. Then wait a few moments for yoke start to collapse back into propeller shaft under it's own pressure. Then give another pump of grease, you'll see slight extension on yoke again. Then wait a few moments for it to collapse again. Keep repeating this until old grease passes out seal. Patients is key, as is not putting to much pressure on inner lip of seal (extending yoke). These seal are incredible tight. This pumping action (priming) doesn't always work especially if your rig has been properly serviced (greased) over the years, which keeps seals in good condition. If you don't see the grease pass seal just drive. If you've extended the yoke to much, say over 3/8", relieve pressure by remove & replace zerk. Repeat again every 5K miles or sooner, using #1 grease if you like, it flow easier.

 

[Verybadwizard]

Thanks for the response this may be a newbie question but do the zerks just twist off like a scr

 

[2001LC]

Yes, just like pictured above. You can see grease fitting (zerk) has threads!

Note:

On spiders (U-joints) the zerk screws into a block the is fixed to the spider.

Zerks need not be removed to grease joint(s)

 

[nissanh]

Here is what I do.
After pumping grease, remove the grease fitting and bump the truck to push-put any excess grease. Then put back the grease fitting. It is a good idea to remove the slip yoke and manually remove old grease and replace with new.

 

[Verybadwizard]

Thanks for all the advice! I raised the vehicle and primed the shaft but I wasn't able to get the greese to pass the seal. I had to go to the next step to relieve the pressure I had built up. I removed the zerk (7mm socket) and went on a drive. A bunch of grease shot out so I put the zerk back on and did two pumps to top it back off. In a few hundred miles I'm gonna try the whole process again and see if anything has loosend up and I can get greese to pass the seal. Thanks again everyone for walking me through this!