Tapping slip joint for grease zerks...

anyone have their slip joint tapped to add grease zerks to make the job easier? cant cost much to have a driveline/metal-fab shop do it, and would make life alot easier.. maybe one zerk on each side of the slip joint? curious to see if anyone has done it...

 

bump. id like to do this or have it done.

 

I'm a machinist @ pearl harbor and i can tell you thats its pretty easy, but you'd have to take it apart to make sure there are no metal chips and/or burrs on the inside.

I found this and they say it needs molylube.

 

You would also need to have a path cut through the Splines so that the grease will distribute itself around the shaft.

 

no. if you took the u-joint apart and drilled into the top of the female yoke end, with a 90 degree angled zerk, it would go throughout the slip joint while you pumped it

edit: http://www.youtube.com/watch?v=uE10x7djc-U

like that.

 

I concede. You are correct!

 

if i were a little more confident in my drilling and tapping skills id do it today. you know how much time that would save??? someone should do it and post a write up for us n00bs.

 

I saw in another thread that it needs to be lubed with moly. I personally have never seen moly lube in a grease gun before. I'm sure its available tho.

:edit:
nevermind, I found some. Might have to try it myself. We have tons of zerks and pipe tap sat work.
http://www.grainger.com/Grainger/ULTRALUBE-Moly-EP-Grease-6ZKW4?Pid=search

 

While stepping up in tire size this weekend, I decided to also do this.
Piece. Of. Freaking. Cake.
Seriously- took me all of 30 minutes (29 minutes of which was spent growing a third hand with which to wrestle the U-joint press setup. ...well, maybe 20 minutes).

While I don't have pics (it's really, really easy, and not much to see with pics), here's the how-to:


Materials/tools:
Hands, preferably three
Beer
Toyota Tacoma pick-up truck, preferably the RWD or 4WD model
Garage, or space to park the truck
Needle-nose pliers
Two different-sized sockets
Large C-clamp
Harbor Freight super-strong rare-earth mini-magnets
Extra hyphens for the next time I have to type the above sentence
Screwdriver or other long skinny object
Centerpunch
Hammer
One 90* zerk ("grease fitting", in layman's parlance)
Quality cordless drill
One thread tap to match thread size and pitch of zerk
One drill bit to match thread tap diameter (Schlep Boys sells them in a matched set)
Optional: One smaller drill bit
Beer
Optional: tap handle (I used an adjustable crescent wrench, but I'm also very steady-handed and can tap straight without a tap handle)
Loctite Red (high strength) threadlocker
Small adjustable crescent wrench, or 5/16" open-ended wrench (or whatever size your zerk is)
Long-handled dental hook or pick
Optional: ~1.5" hose clamp
Quality grease, like Crisco
Grease gun
Shop towels
Brakleen
Keys to truck
Pavement, or at least some place to drive the truck
Girlfriend of choice (I recommend your own, but I'm sure you can borrow a friend's if needed)
Beer

Procedure:
Obtain truck. Park in garage, or a flat space on the ground where it will fit. The neighbor's lawn is usually about right.
Open beer. Drink.
Remove the U-joint retaining clips on two opposing caps of the slip yoke (not the driveshaft side). I chose the cap with the zerk in it, and its opposing partner.
Press out the caps using a large C-clamp and two sockets: one socket needs to be ever-so-slightly smaller diameter than the outer diameter of the U-joint cap, and the other socket needs to have an inside diameter ever-so-slightly larger than the outer diameter of the cap. Press one side out, then flip the sockets to the opposite side and repeat. You should end up with two U-joint caps in your hand. KEEP THEM GODLY CLEAN!!! Do NOT allow any dirt or debris in them!
Free the clamp on the small end of the slip yoke boot. Just slightly pry up the tiny retainer tab and it'll pop open. You can re-use it if you know what you're doing -- otherwise, just replace it with a hose clamp.
Carefully work the slip yoke free of the U-joint spider. It's fairly obvious how to do it when you're down there. Now slide the slip yoke off the driveshaft. No need to mark its orientation- it's keyed to the driveshaft, so you can only install it one way.
Okay, so at this point, all the hard work is done (that would be needing three hands to press out the U-joint caps). You should have the outer half of the slip yoke in your greasy little hands.
Find the center of the end cap of the shaft. Dimple it so your drill bit doesn't wander.
BEFORE YOU DRILL!: Drop some Harbor Freight super-strong rare-earth mini-magnets (about 5/16' diameter) down the inside of the shaft, where the grease is. You're probably going to need to push them down with a screwdriver so that they reach the end of the shaft. Make sure you have at least three in there. Also put three on the outside of the endcap, right where you're going to install the zerk. The idea is that these super-strong magnets will collect all metal shavings......quite effective if you take your time and stop every few seconds to clear chips and shavings before the bit penetrates fully.
Using a SHARP BIT (though I have a nice new set of cobalt bits, I used a cheap tap/drill bit combo set I picked up at Schlep Boys), drill slowly, stopping every few seconds to clear chips and shavings before you penetrate the cap. I would personally recommend drilling a small pilot hole first, then follow it up with your final-size bit, because this is the most effective way of keeping things from walking. If done right, you should be able to punch through without a single shaving getting inside the slip yoke. I would recommend against a high-torque wall-powered drill, and opt to use a high-quality cordless drill. Too much power means you're going to punch through too fast to be able to clear shavings.
Next, use your tap to thread the hole. You're likely going to be using a 1/4"x20 thread, but check your zerk's thread to be certain. You want to make sure the zerk threads match the tap threads. GO SLOWLY! Make dead certain you're dead straight and dead perpendicular to the end cap. Thread all the way through, going the entire length of the tap threads, in one direction only -- DON'T back out until you've reached the end of the tap threads. Once you reach the end, slowly back out the tap, and remove any shavings.
Take the magnets off the outside of the endcap, and thoroughly clean the outside of the cap, making sure there are no shavings anywhere.
Add some Loctite Red (high strength) threadlocker to the threads of the 90* zerk and carefully screw it in, making sure it goes in straight. Snug it down nice and firm, but DO NOT OVER-TORQUE IT!! Make sure it faces about 45* to the centerline of the U-joint holes (you'll need to get your grease gun in there, and you won't be able to if you angle it perfectly 90* to the U-joint centerline), and make sure that the last direction the zerk was cranked on was clockwise (tight) -- the last thing you want is it to fall out, even with the threadlocker.
Open beer. Drink.
Now retrieve the magnets from inside the shaft. You'll need a screwdriver for this, and likely some kind of hooked pick. Slide them up and out. While I don't guarantee you won't have any metal bits left in there, it is very unlikely with three high-power magnets sitting in there the whole time. (Full disclosure: I did not flush out my shaft after drilling. I simply retrieved my magnets and called it a day. There were very few metal bits on them......most of the metal bits were on my magnets on the outside).
Re-install the slip yoke back into the truck, reversing the removal procedure. First, thoroughly clean the U-joint spider ends until you're comfortable licking them. Pressing the caps back in is exactly the same process as pressing them out, but it'll be easier because you've already just done it and now are an expert at it. Press one cap in, and, BEFORE PRESSING THE OTHER CAP IN, install the retaining clip -- this provides a very obvious stopping point for when you're pressing the other cap in. Remember to install the other retaining clip! Re-secure the boot (I re-used the factory clamp, because I figure using a hose clamp throws the balance off).
Now, spend what seems like an eternity stuffing it full of grease. Seriously- you're going to think you're emptying the entire tube in there. Periodically press the rubber boot with your fingers to see how much you've pumped in -- you shouldn't completely fill the boot (remember! it has to have space to slide!), but you should thoroughly stuff the first bellows until it feels firm-ish.
While you've got the grease gun out, top off your U-joints -- especially the one you disassembled.
Now, go drive it around the block so you can fling all the excess grease onto your hot exhaust so your gf's nose knows what an awesome job you did.
Open beer. Drink. Repeat until gf's complaint about hot grease smell disappears.

As for type of grease: First, I don't worry about it because I use RedLine, which is pretty much the hands-down best grease available (it outperforms literally every single grease you can find, and RedLine is the ONLY lubricant manufacturer that uses 100% synthetic base stocks for all their products......even Mobil1 can't claim that). Second, I did mine at 17K miles; the grease that was in the slip yoke was nice and clean......and RED. That means it is most certainly NOT moly. I suspect it is a synthetic, likely Mobil1.

Service your slip yoke zerk at the same interval you service your U-joints (15K).

I might, maybe, sometime, get some pics up.

 

i dont feel comfortable taking apart my u-joints, so id prob just slide the slip yoke apart, and put a zerk in the side of it.

 

1) Balance issues. You're talking about something that is balanced to at least 10,000 rpm.
2) The side is tremendously more meaty than the endcap, and is of a higher temper. Good luck tapping that!
3) You need to stuff the grease into the endcap area- otherwise, it won't spread to the areas it needs to get to.

Besides, U-joints are really easy to take apart. Easier (and safer) than you probably think. Plus, if you ever go off-roading, it's good practice to understand how to do it in case you break one (rather common) -- and what better time to figure out how to do it than in your garage/driveway/neighbor's lawn (rather than the middle of a rocky trail)?

If it helps: I'm generally entirely too verbose. Especially in step-by-step instructions. So what looks like a multi-volume encyclopedia set of instructions, it's really just a lot of words to describe a simple process.
I could make shoe-tying sound more complicated than building a Mars lander.

 

Like Mach said, if you're not getting the grease to the right place... You're wasting your time!

U joints really aren't complicated at all, and don't require any special tools

A few other tips...
Keeping your drill bit wet with oil or grease helps with drilling (lubes and cools) AND keeps chips from flying where you don't want them. Wood bits arent sufficient, you need HSS or cobalt, dont fall for "titanium coated". The magnets are a great idea, I often have my shop vac helping as well

 

Has anyone else done this? Wondering how much room there is if you put a 90 degree zerk in the end cap of the slip yoke?

 

Now that some time has passed, how has been working? Can you grease it? I looked, not sure I could fit the coupler in there to grease? Got a picture of yours? Thanks.

 

Does very well.
Using a 90* fitting, and lining up the yoke so the fitting is pointing down, I can get my gun on it no problem.

I have found out (the hard way, of course), that one should not pump too much grease into the yoke, and even better if one of the clamps can be loosened and the boot squeezed some prior to greasing. Doing so causes the boot to pop ("explode" could possibly be a more appropriate term) at speeds above 80mph. Also, speeds above 90mph will do the same, regardless of overfilling or not.

The "proper" amount of grease can be checked when filling it. Periodically give the boot a squeeze with your fingers, and once you can feel the grease filling the first crease in the boot, you're good to go. If the boot starts swelling significantly, it's overfilled.

Don't grease it more than once a year, and no more than a half-dozen pumps max.

 

I'll see if I can get a pic up sometime. No promises (though I do need to do a LOT of crawling under the truck soon!).

 

Thanks!!!

 

I know it’s been a while but does anybody have pictures of where they put the fitting?