I recently bought a 1997 F150 4wd 5sp manual. While changing the fluids, I noticed that the front u joint on the rear drive shaft has a grease fitting. No matter how I rotate that shaft, I cannot access that fitting with my grease gun, even when fitted with a flexible rubber hose. Any suggestions?

Thanks, JB

 

I have seen some that I had to unbolt the drive shaft, turn the joint full to the side and grease.. Sounds like excess work, but you only do it every couple years and it only takes 15 minutes.

 

The rear drive shaft on my truck is only unboltable at the rear. The bolts are like none I have ever seen: They are not hex headed, but have 12 ridges. A 13mm 12 pt socket is too loose, a half slips over, but is not the right thing. 12mm or 7/16 are too small.
They are stamped 12.9 in the center of the heads. Does anyone know the size of these bolts and the proper socket to remove them?

Thanks, JB

 

Gotta pic of this? Thought there was a thin wall grease gun nozzle for that kind of problem. This must be something different.

 

I had a small zerk gun fitting that I used for those tight spaces.

 

Thanks for the suggestions. I did a search on the main site, and the bolts are 12mm 12 point. That info courtesy of a Ford senior tech. I must have picked up and 11. The problem is the angle at which the zerk is inserted in the uj. If one shot a laser beam down the center of the zerk from the inside, it would only clear the body of the yoke by a whisker, and that yoke is only about a half inch away. No matter how thin walled the grease gun nozzle is, it would have to have a curve in it at the tip to make a fit.

Best thing is to disconnect the shaft at the rear. Not a big job after you figure out what the bolts are.

Thanks for all the input.

JB

 

With stunts like that, maybe "permanently lubricated" isn't so bad?

 

They make a needle adaptor to deliver grease to those. The tip of the needle fits tightly in the hole of the grease fitting. Don't force too much grease in the u joint, it will damage the seals.

 

It's my understanding u joints are supposed to be purged. Spicer recommends this??

 

If you jack up the back of the truck and let the rear axle drop down you might get enough driveline angle change to get at the grease zerk. It worked on my 94?

 

That's an intelligent idea. Thanks. JB

 

Jack truck by the reese hitch, and let the axle hang free, you can reach it from the top most of the time this way.

 

12.9 stamping on the bolt is a BOLT GRADE in metric... we use grade 2, 5, 8 in the US... they use similar in metric... 12.9 is similar or a little harder than grade 8 US.

 

According to an old parts guy that knows his stuff, "the a new replacement u-joint with a grease zerk has assembly grease that needs to be purged out and that running with w/o real grease will significantly decrease the life of the U joint". I've never had to re-replace one since I followed this advice.

 

Ok. Well apart from that, the idea in general lube service is to pump until old grease is seen, to get the grit out of the joint and replaced with clean, fresh grease.