Rear Axel Grease Zerks

On the rear axel, there are grease zerks for what I’m assuming are the wheel bearings. Normally when greasing I pump until I see a little fresh grease starting to pop out. But on these, I don’t see a place to see it come out, so how many pumps do you guys put in them?

 

I give mine one or two pumps 1-2x year you can blow the seal if carried away.

 

There is a vent hole, yours may be clogged with dirt.

 

For some reason, I think "three" was the spec, but I don't recall where I got that.

Part of the confusion re: vents etcetera may be due to the miltary axle and the civilian axle being set up slightly differently.

 

The service manual says: "With Lube Fittings: Sparingly each 2000 miles, Without Lube Fitting: Disassemble to lubricate each 12,000 miles"

 

As I understand, they later quit putting them on because of blown seals from too much grease.


Dave

 

I do what FSM says every Spring.

 

All two piece rear axles have grease fittings. The flanged does not.

 

"All two piece rear axles have grease fittings"

This is incorrect, I am not sure when they quit installing them, but I have two 67 CJ5s with tapered (two piece) axles that do not have the grease fittings nor vents. I have two sets of military surplus M38A1 axles with tapered axles which do have the fittings and vents. The M38A1 axles are Marine surplus so are probably from the late government contract which puts them in the same era as the two 67 civilian Jeeps.

I don't count the pumps of the grease gun. I watch what is coming out of the vent until I see clean grease. If you pump slowly the incoming grease will push out the old grease within the bearing. If you pump too aggressively the incoming grease will go around the bearing and out the vent. You should see a pretty good glob of dirty darkened grease come out before clean grease.

As I see it, one problem with this lubrication system is if the vents aren't clear grease under pressure can breach the axle seal and get into the tube. Another possible problem I have suspected is the vent may allow a small amount of water intrusion if submerged long enough, but the axles should be flushed after significant use in water anyway. When I tore down the axle in my CJ2A the right side tube was full of brown muddy looking grease.

 

I think Gravely or Scag used to have a spring loaded vent for the spindle bearings on their mowers. Might be a good idea to fab up. I added grease fittings to my flanged Dana 60 that takes early 70s CJ axle bearings. I pull the brake drum when rotating the tires and pump a few squirts until I see the seal lip just start to seep when I rotate the axle with my 3rd hand. By the next time, a few drops may have fallen out or get dribbled around the seal but the bearings are still working just dandy.

 

Last time I was in mine I was puzzled about these as well. There was a lot of grease sitting in the tube but no way that zerk was going to keep the bearing full.

 

As long as the seals are good it will work if you first clear the vent, and then pump slowly.

 

Don't forget to run both the inner and outer seals when using the grease fittings..

 

Sure wish that I had a " 3rd Hand " Some guys have all the Luck.......

 

I put zerts on my Flanged 44 I plan on giving them a shot about once a year.

 

I owned a 3B that had the fittings on it. always put a couple of pumps in them about every oil change. Never had a problem with the bearings or with grease getting by the seals.
On the other hand my 74 with the flanged axel I had never had them out or serviced them until about 30K miles. Pulled them out, still had plenty of grease (factory is usually very lite on greasing things) I cleaned and repacked them with regular wheel brg grease. I have not had them apart or greased them since but they are apparently still ok, no leaks, noise, or looseness. 120K miles now. I will pull them when I start my rebuild, will see how they look.

 

My 70 flanged has the grease fittings.

 

My flanged does not.