2nd Gen Non-Engine/Transmission Greaseable vs non greasable u-joints / when & how to grease them / life expectancy.

[Dan_69GTX]

Do you prefer greaseable or nongreaseable u-joints? Why?



When greaseing u-joints (provided they are greaseable). Do you add grease until you see grease coming from all 4 trunions or do you grease until you feel slight pressure (before grease shows anywhere) and stop?



What life have you gotten from greaseable vs nongreaseable joints?



Thanks!

Dan

 

[propuller]

Dan it depends on what you do with your truck. If your on the road alot & not beating your truck i would say get the greasable ones. If your into sled pulling or drag racing get the solid cross or non greasable ones. The reason is that the greasable joints have a hollow cross & they are weaker than the solid non greasable joints. I run the brute force non greasable solid u joints in my truck but i beat the crap out of it to. The spicer non greasables are excellant also just a little more $ than the brute force joints.



Kurt

 

[JJW_ND]

Non Greaseable....

I changed my factory orginal joints at 210,000. Not becuase they were makeing noise or causing problems while having the rear shaft balanced (chasing a vibration issue).



Lots of heavy pulling (ate tires on the rears like crazy), some off road and gravel driving in those 200K miles.



The joints were good enough to be reused.



The driveline shop I used likes greaseable joints (even though I asked for Spicer (factory original). After 30K miles I now have a nice grease ring near each joint location on the fuel tank, frame etc. I grease every 6K, wipe excess off... .



If I ever do it again, I will go with non-greasable.



jjw

ND

 

[jeepit]

You want to gease until the same color grease that goes in comes out all trunions. This way you flushing out any particles of dirt and moisture.

 

[Joseph Donnelly]

Most failures are from lack of grease, so greasable is good. Be sure to load the zerk hole under compression. Envision one pair of trunnions being turned and the others resisting that motion. You can see that two possible positions (between trunnions) are being "stretched" and the other two are being compressed. For ultimate strength in competition, the solid joints may be a little stronger, but brand, metallurgy, also matter--a lot.

 

[barepa]

I like greasable, the flushing idea, but I have only replace one of them in about 400,000 miles. its a road truck. I check them often.

 

[drrhoades]

When you install greaseable joints be sure to install so the zerk hole is under compression like Joe said and when you grease them be sure to use Extreme Pressure grease, not chassis grease or whatever is in the gun, and make sure that new grease comes out of each bearing cap. I would use the Spicer joints.

 

[rrausch]

Another vote here for greasable U-joints. I replaced mine after one went bad at about 135,000 miles. I grease them every other oil change, or 10,000 miles.

 

[DSiemens]

My vote is for grease-able U-joints. I only apply grease until the u-joint snaps or crackles. At every oil change, u-joints are greased.

 

[Diesel Gunner]

IMHO if one greases a u-joint until grease comes out you have successfully blown the seals. Now water and grit will have a much easier time getting inside. It would be very interesting to hear from a u-joint manufacturer about the proper procedure for lubricating a joint.



In my early years as a mechanic, I was trained to apply lube slowly until the seals began to move, expel air, and/or slight resistance was felt in the hand operated grease gun. Keep in mind that the lube inside the cross trunnion will be forced out into the bearing caps by the rotational forces of the rotating shaft.



In a recent technical seminar that I attended I was suprised to learn that bearing manufacturers consider a bearing that is 1/3 filled with lubricant to be "Full". Any amount of lubricant beyond this amount is considered excessive and can even cause bearing temps to go up. I am willing to bet that most all of us who have "hand packed" bearings, pack them full, apply grease to the cup, and then add a dab more before closing things up. The SKF Rep assured all of us that that was wasted lubricant.



Keep in mind that the grease on the outside is only protecting the outside. It is doing nothing for those more inportant parts on the inside. Just my $. 02

 

[jeepit]

The Jeep I take off road gets caked with mud and water. Not only is it a pain in the a. . to clean, I also have the underside to worry about. IMHO if I don't force the water and dirt out I will just have moisture and dirt eating away at the needle bearings under the caps.

 

[cmills]

question

Sorry if this is a dumb question, but what do you mean when you say make sure the zerk is under compression?





Cory

 

[QRTRHRS]

I was also taught to not overgrease U-joints. Is there a difference in the way the seals are manufactured these days as opposed to 30-40 years ago?

 

[Rman]

Originally posted by Diesel Gunner

IMHO if one greases a u-joint until grease comes out you have successfully blown the seals. Now water and grit will have a much easier time getting inside. It would be very interesting to hear from a u-joint manufacturer about the proper procedure for lubricating a joint.



In my early years as a mechanic, I was trained to apply lube slowly until the seals began to move, expel air, and/or slight resistance was felt in the hand operated grease gun. Keep in mind that the lube inside the cross trunnion will be forced out into the bearing caps by the rotational forces of the rotating shaft.



In a recent technical seminar that I attended I was suprised to learn that bearing manufacturers consider a bearing that is 1/3 filled with lubricant to be "Full". Any amount of lubricant beyond this amount is considered excessive and can even cause bearing temps to go up. I am willing to bet that most all of us who have "hand packed" bearings, pack them full, apply grease to the cup, and then add a dab more before closing things up. The SKF Rep assured all of us that that was wasted lubricant.



Keep in mind that the grease on the outside is only protecting the outside. It is doing nothing for those more inportant parts on the inside. Just my $. 02

This is 100% correct and the reason I always use sealed joints. They're easy to replace, I carry 4 of them with me when I go wheeling. Zerk fitted ones are weak and prone to premature failure because of blown seals... . I've had a joint blow doing 65 mph... it was a scary thing. I replace them at least once a year now on my trail rig. I haven't set a pattern for the pickup yet, I'm waiting to see how they hold up.

 

[drrhoades]

Dana/Spicer days that you are supposed to grease the u-joints until all of the seals purge the same color of grease. This is Spicers recommendations. http://www.spicerdriveshaft.com/literature/pdfs/lubrication.pdf

You purge all of the seals so that any contaminats that are in there are removed then you wipe all of the excess grease off as best as possible. Now if you are working with non greaseable u-joints then you must be very careful to not purge the seals because then contaminants can get in there very easily. If the greaseable ones are lube properly they will last along time.



Doug

 

[jeepit]

Ya hey, that's what I thought. The seals are made to release one way; to allow dirty grease out and not flex the other direction to try and keep clean grease in and contaminants out.

 

[Dan_69GTX]

Well, I finally got ahold of someone at Spicer/Dana and can answer the questions I posed.



I spoke to 2 people, Joe and Rick.



Spicer recommends a greasable joint be greased until new grease comes out all 4 seals.



Due to their new seal design a choice between an older greasable joint and a new non greaseable - a non greasable would be prefered.



Non greasable are much stronger.



Make sure the grease is compatible and must be NLGI 2 and EP (extreme pressure).



Properly taken care of (no major shocks, etc) and greased at recommended intervals a greasable will last longer than nongreasable. Problem is most people don't properly maintain.



Much literature is at:

http://www.spicerdriveshaft.com/literature



Dan

 

[Boomer II]

Originally posted by cmills

Sorry if this is a dumb question, but what do you mean when you say make sure the zerk is under compression?





Cory

Yeah, what Cory said.

 

[SS]

Good question!

Originally posted by cmills

Sorry if this is a dumb question, but what do you mean when you say make sure the zerk is under compression?





Cory

A typical greaseable U-joint has the zerk at a 45 degree angle to the cross (between 2 of the legs on the cross).



Try this - imagine placing your thumb and forefinger from each hand on top of the U-joint caps. Now rotate one hand until your fingers and thumbs touch. That's where you want to place the grease zerk - as if it were being compressed between your fingers. Same thing on your driveshaft and axle yoke - you want it in the compression position as they rotate when the vehicle moves forward. The cross can withstand the torque of forcing the threads on the zerk together better than pulling them apart. Hope that helps to visualize it... .

 

[Diesel Gunner]

drhoades and Dan_69GTX,



Ok, I will defer to Spicer. I read the lubrication literature at their site and still have a few questions. I completely agree that if a different lubricant is used than what is currently in the joint it should be purged. However, purging may not be the answer as it is not possible to remove 100% of the old lubricant in this manner. Disassembly, cleaning, relubricating, and reassembly is the only sure way to accomplish this. One heck of a lot of work, for sure. If the different lubricants are incompatible the purge method may not be sufficient. Incompatibility would lead to early failure. Who would be willing to go through this much work to change lubricants? I would run the joint till it needs replacement and then change lubricants.



My second question is that the literature refers to aluminum steering shaft yokes. It the same procedure recommended for drive shaft yokes?



Finally, and I will still defer to Spicer (if the procedure is the same for driveline yokes), if a u-joint is lubricated properly and at a regular schedule(determined by the type of use), it should have sufficient lubricant in it to keep the seals seated. This would be accomplished by the grease being forced into the bearing caps by rotational force and keeping them seated. With the seals seated properly, dirt and moisture intrusion would be minimalized, and the grease should be retained within the bearing caps. I have seen many u-joints that will expel water and air when lubricated. I had always thought that it was caused by someone before me "purging" the joint and causing the seals to lose their ability to "seal".



Interesting discussion.