Driveshaft greasing questions

Hey gang, while doing some Jeep work today, I remembered that I haven't greased the driveshafts, ujoints, pedals, or any other greasepoint recently. Well, my buddy loaned me his grease gun (we were at his house), and I got greasing.

When I greased the front drive shaft, grease came out at the slip joint(?), after two pumps.



So I moved to the rear drive shaft. After five or six pumps I had nothing, then on the next pump, grease propelled out of the front of the shaft towards the ujoint! :? I am I missing something here? I don't think this is normal, and I dont see any fitting remants... Any suggestions here? I apologize for the bad pics, and the angles, I upload them oriented correctly, but imageshack keeps turning them???

Grease at the front ujoint, on the rear shaft.



Slip joint, lacking much new grease.

 

Grease should come out by the u-joint. There is a small vent/air hole there that is probably plugged on your one shaft. There is supposed to be a seal between the slip yoke and splines. My guess is yours is missing or blown out caused by the vent being plugged or rotted away. Common for this to happen.


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There's a little vent hole on the front of the slip joint-that's where the excess grease is supposed to come out. That is normal. The front one is actually your problem-for that much grease to come out around the splines, it's probably getting sloppy. But, since it's on the front & doesn't turn most of the time (assuming you have lockout hubs) I wouldn't worry about it.
And remember-you can't grease a Jeep too much! IMO It should be done with every oil change, and after every off road trip involving water/mud crossings.

 

IIRC there is a felt ring under the sheet metal cap on the driveshaft splines. That's all that keeps the grease in. If you put a lot of grease in there, some will come out under the felt ring. Not a problem. Also, the rubber seals on the u-joint caps will deform and let grease out if you force a lot of grease into the u-joint. Also not a problem - just wipe it off.

Finally, it seems like the old grease builds up a cap of hardened dirt and grease that blows open when the grease gun pressure gets high enough. If you grease regularly, I'd expect the grease to stop spurting out in a big blob. It's a good idea to grease often.

 

Thanks guys! I hoped it wasn't anything bad! I haven't greased the jeep down in about a year and a half (<2,000 miles), so I figured it was overdue. I couldn't get to the ujoints on the front driveshaft, not enough room, I guess I need one of those needle fitting things, for lack of a term.

Then I just have to take care of that u joint that has a gaping hole where the grease zerk was...

 

Gonna go get a grease gun and grease friday, still have to grease two other cars.

Anyone recommened anything inparticular?

 

I remember reading in a old service manual that when greasing the slip joints you should use your finger to plug the vent until you get grease out of the splines while greasing.
Might of been the old MB book.

 

I would certainly get a quality grease gun. You will be glad you did. I have a Lucas purchased at Home Depot. I figure it was not the cheapest place to buy but I was using Christmas gift cards. I also purchased a tube of the Lucas grease at the same time. I think Lincoln makes a pretty good product as well.

 

Here's the one I have: http://www.amazon.com/Lincoln-Lubri...1349350408&sr=8-1&keywords=lincoln+grease+gun

Here's the one I'd like to have: http://www.amazon.com/Lincoln-Lubri...1349350408&sr=8-2&keywords=lincoln+grease+gun

 

I honestly wouldn't do this. The later slip yokes have the seal in the splined area. Grease under pressure can penetrate the skin. Not good.

I prefer the pistol grip type of grease guns. You can pump with one hand while holding/moving around the fitting with the other. Much easier. I have two. One of the small ones found at most flaps and a larger one. The small one is great for tight areas and the larger one doesn't need filled as often.