• Hello Guest, we are proud to now have our Wiki online that is completely compiled and written by our members. Feel free to browse our Jeep-CJ Wiki or click on any orange keyword when looking at posts in the forum.

U joint rules

U joint rules

driver007

Senior Jeeper
Posts
610
Thanks
1
Location
Canada
Vehicle(s)
1981 cj5 304 v8, 300 Dana,model 30 Dana and model 20 AMC rear end
If your installing some ujoints is there some old school rules on the install. I was thinking about what side the grease zerk faces? Should the side of the ujoint with the grease zerk face the drive shaft of the diff etc?
 
I've always put them so the zerk is in the most open void available, typically towards the driveshaft.
 
There is a thought among some jeepers that a grease fitting weakens the U-joint. That's why many won't buy a joint with a fitting.
 
I really did not realize that there were any options on how it goes in. I have reduced the size of the nozzle to get them to fit better though. You can get an extension zerk if it gets too tight, then replace it with a plug when you are done. I always buy the Dana-Spicer brand of u-joint.
 
Depending on your DS angle, if you've got them the "wrong" way, it can be tough to get to them.


Wooly
 
After going through what I did with my axle Ujoints I'll only use greaseable ones. They were bound and needed to be cut out with a torch.
 
Grease zerks go in line with the spline zerk always facing the DL. Why should you rotate to lube each one each time or remove to grease.
 
Last edited:
put some more grease down in the cups (about a quarter the way up) it helps to keep the pins upright when you put them in.
 
There is a thought among some jeepers that a grease fitting weakens the U-joint. That's why many won't buy a joint with a fitting.

Been run'n zerk 'joints' in my jeep since new(1985),never had one fail.
The only u-joint I ever had break was in the front axle, and it doesn't have a zerk.;)
Buy the best ones, which are Dana-Spicer. Do do the cheap on u-joints.
LG
 
I always buy the best and agree that few if any grease fitting joints will fail, but the owner of Willys Works always mentions that a u-joint that is drilled for a fitting is weaker than those that aren't. He also says that few if any owners grease their u-joints, naturally when installing the joint they are greased.
 
The grease that's in the u-joint when it comes out of the package is there to hold the rollers in place and prevent rust in storage.
That 'joint' is not greased for use till the installer adds some.
LG
 
The front driveshaft on the Transfer Case side must have the zerk facing the drive shaft so when you reach in from the front with the skid plate in place you can get the grease gun fitting on it.
 
LG - Didn't say that you shouldn't add grease. Argue your point all you need to, didn't really say you were wrong, but I do know and do remember correctly what a jeep parts man and mechanic for 45 years said about u-joints.

Doesn't matter, I only mentioned that as side information, the PO already bought his u-joints and I would have done the same as he did. I also didn't know there was a right and wrong way to install a zerk fitted U-joint.
 
LG - Didn't say that you shouldn't add grease. Argue your point all you need to, didn't really say you were wrong, but I do know and do remember correctly what a jeep parts man and mechanic for 45 years said about u-joints.

Doesn't matter, I only mentioned that as side information, the PO already bought his u-joints and I would have done the same as he did. I also didn't know there was a right and wrong way to install a zerk fitted U-joint.

The biggest issue is when folk think all u-joints are the same and try to save a few bucks with China made JUNK.
BTW-Zerk fitted u-joints were OEM for the Jeeps, for many years. That's smart.
Install the zerk to the inside of the DS. That way it's away from the torque load.
LG
 
Replacing, fixing & making DL`s, most of the time it was lack of lubrication. Either from not having a zerk or not greasing them, never had a Spicer (the original encased u-joint since 1904) break at the zerk. So the theory of a weak zerk does not hold water with me, unless we are talking improper install or Chinese or the lesser u-joints, which I have broke just from installing them. If you do not like zerks (since maintenance free products have more sales appeal to the masses) then by all means every 3 months disassemble them and lube. We can not go back to Chinese gimbals or Cardano`s Joint, it has to be enclosed and be able to lube.
If a nipple hits then replace with a needle or with a capped nipple.

If you do not believe me!
Here is a link I will call U-Joint 101.
Driveline Lubrication

For further reading study Clarence W. Spicer.
 
There seems to be a belief that a u-joint without a grease fitting is a cheap or inferior part. Not so, Rob at Willys Works hates most everything made in China and he won't stock or sell cheap parts. He was passing on information drawn from his many years of jeeping experience. Please don't pile me in the No grease fitting on u-joints crowd. I have never broken a u-joint, I have warn out and replaced a bunch of them.

and

I use Champion spark plugs, but my CJ has a V8 in it.
 
I've always believed "no maintenance" hard parts like zerk free U-joints was nothing more than a marketing ploy designed to guarantee the sale of replacement parts. Probably not so, but I tend to be negative anyway, sometimes :D.

I like being able to grease anything possible by hookin' a grease gun to it. I regularly ford streams and find comfort in the ability to push water out of trapping places (like U-joints) with a few pumps of the G-gun. I feel it cuts down on the R&R frequency.
 
It is all good guys, it is still not as bad as brown bottle breakage. Or that the Deer is the most dangerous animal in North America.
 
Warn industries tested several 297 series u joints both greasable and non greasable. I used to have the complete testing results on my old ipad. ( death by concrete slab) I did however find a partial on another website...https://www.ringpinion.com/Content/Book/Front-Axle-U-Joints-101.pdf

We have found That greasable joints, installed correctly with the zerk in the correct direction of applied torque (LG)are stronger or at least they break less frequently. Probably because they can be purged of dirt and water .As a side note not all spicer joints are created equally either, some of there joints are actually weaker than other brands.
 
Also full circle clips are a must if you are pushing the joint harder than recommended I.e. V8 /Dana 30
 

Jeep-CJ Donation Drive

Help support Jeep-CJ.com by making a contribution.

Help support Jeep-CJ.com by making a contribution.
Goal
$200.00
Earned
$0.00
This donation drive ends in
0 hours, 0 minutes, 0 seconds
  0.0%
Back
Top Bottom