04 DC 4WD slip yoke greasing problem

Disclaimer: this my first attempt greasing the zerks on this truck so I may be missing something completely obvious

So I go to grease the zerks today and things are looking as expected then I get to the slip yoke which is the main reason I’m doing them in the first place (I have the “thunk”). I’m looking everywhere for the zerk for the slip yoke but all there is is a hole about 1/8” in diameter where the zerk should be. See picture below. I checked the whole circumference of the shaft to make sure I’m not missing it. This hole is all there is. This isn’t normal is it? No zerk, just a bottomless hole? Maybe previous owner sheared it off, but I can’t see any remnant of a fitting in there nor does the hole even look threaded. Also I would think the hole would be bigger, but that’s a guess. Did the guy at the factory just drill a pilot hole then forget the rest? Or am I just an idiot. Seems weird for it just to be a hole…

 

I never noticed a hole on mine but I don’t have an 04 DC.

 

Yep, that's your problem. I guess the previous owner wasn't being honest about greasing all the zerks himself, eh? Should have zerk installed, someone screwed it out or it fell out. You could temporarily swap another over into it, grease it, jump on bumper, grease, jump on bumper, then pull to relieve pressure, and reinstall the zerk wherever you borrowed it from ... but you should probably replace/

Please see this thread (edit: added link), the yellow circled zerk, for what was there. Read FGV's reply # 4 for link to info on how to lube it once you reinstall a zerk. That is undoubtedly causing your thunking problem IMHO.

I forget what the threading is on the driveline zerks is, someone posted it in the last 2-3 weeks.

 

Here you go - the zerks are metric, size M6 thread pitch 1.0

1/4 won't fit.

 

I greased mine a few weeks before my road trip. Took the noise away at first but it’s back again. I guess it’s time to hit them again.

 

Awesome. Thanks.

There’s grease slung around everywhere else, so that’s a good sign. But maybe he smashed this one off. Who knows. I’ll try out the m6-1.0. The hole seems way small, so I may have to just drill it and tap it.

 

I still can't get my grease gun to work on the 4WD shaft. Such a simple yet frustrating task.

 

My dewalt cordless works great. The front zerk on my Deere was a different story. Had to take a unibit to the small hole in the frame to get the tip to fit through it.

 

I got the lock n lube name brand attachment tip. I’ll post a review on the what have you done to your first gen thread after doing the whole driveline. Did one or two zerks with it the other day and it was awesome.

I’m still baffled on what this hole is originally from because I don’t think there’s a way it fit an original m6-1.0 in the first place. It’s at most 3mm in diameter. Maybe on the 04 they just had a hole? But the manual shows the zerk fitting. I guess it doesn’t matter at this point, just a curious finding.

 

Sorry I said 'check this link' but didn't paste the link: https://www.tundras.com/threads/black-hole-zerk-wtf.93630/

Look at the zerk I circled and location. Same spot as that hole. It looks larger than 3mm to me. M6 is 6mm, and that hole looks about 7/32 or 6mm, so ... should be it.

Again, no reason you can't pop off the zerk next to it and test-fit in the hole. It takes 30 seconds. It's totally possible someone hit something and yanked it out, but ...

 

#TIL: 'Circled zerk' is probably what circle jerk sounds like out of a slurring drunk person's mouth.

 

Does it look like maybe the zerk sheared off? Could explain the small unthreaded hole. I can’t tell from the pic.
If that’s the case you might be able to remove with a screw extractor.

 

Or they pumped grease into it 7-8 times and didn’t notice anything coming out the seals so they figured it was clogged and took off the fitting and never put it back on. Not that I would know anyone who would do that.

 

I guess it could be sheared off? But there’s nothing in there, so it would have had to have yanked the whole thing out, which seems unlikely to me. Or he pulled the zerk and never put it back. At this point, I’m on to the solution. Ordered some m6-1.0 zerks and a 6mm tap. I’ll try to thread one in when I get it. If it doesn’t fit I’ll just tap it. Either way, it’ll get a zerk this weekend.