Not the way to start the week

[deminimis]

Drive shaft length is not stock. However, the u-joints are. Some enterprising young man started a parts thread in the 4x4 section with the u-joints listed. Not sure of your year, but you probably have a Spicer 1350 U-joint. Very comon.

Now, if you need better quality U-Joints and/or drive shaft work, the guy in Ogden Utah does some nice stuff and is reasonably priced. http://www.4xshaft.com/index.html

I bought my replacement u-joints from http://www.arizonadrivelines.com/ Good products, but slow on the shipping.

[BroncoHauler]

Well...looks like this may be all out of my pocket (no warranty), but more importantly, likely all my fault.

Heber at SMBw returned my call and left me a message. It seems that my t/c output yoke is one that had been replaced while the previous owners had owned the SMB. It appears that some of the earlier Atlas output yokes for SMB were machined slightly out of tolerance and allowed some u-joint cap movement, which could lead to losing a u-joint cap and more.

Heber did mention that the driveshaft u-joints are greaseable, which definitely escaped my notice and attention. He also mentioned they should be greased every 5000 miles. Since I don't have the SMB at home, I can't verify the u-joints are greaseable, but I will ask for the old parts back when I get my SMB back. I had not greased my u-joints in the 10,000 miles or so that we've owned the SMB. I do know there are 1350 series u-joints available in greaseable and "permanently" greased versions. The greaseable versions have a zerk fitting in one of the crotches of the u-joint.

I don't have all the facts yet, but I want to raise the issue of inspecting & greasing your driveshaft u-joints on a regular basis to prevent a costly and potentially dangerous failure. I guess it's time to refamiliarize myself with the SMB maintenance schedule.


Herb

[adventureduo]

Yep, greasable.. always grease them along with steering and the front shaft. Oh well, live and learn. Like we all said man, at least you or any of your family wasn't hurt. Get a grease gun for those zerks!

[deminimis]

My rear u-joints were the sealed type (no zirks). The sealed type are fine for the family minivan, in my opinion. However, we demand more of our rigs and they are often in environments that can compromise the seal/u-joint. Once a contaminate finds its way into a sealed u-joint, its just a matter of time. With greasable joints, you have to take care of them, but you push out the garbage that gets into them when you grease them. Definately the way to go in my opinion. Its nice that the really good ones are relatively cheap ($25/ea or so), unlike just about everything else. My preference for grease is Redline CV-2 (red moly). It doesn't play well with others, so keep that in mind if you use it (make sure you push out the other grease). I'd recommend you only use it if you do your own maintenence. They won't have it at your local Wal-Mart if you get your oil changed there and not worth running the risk of incompatability. That reminds me, I need to order some to have on hand.

[jage]

Are you supposed to push the old grease out? I'd always heard that overfilling with grease until it came out the seals would weaken the seals or leave them open to more contamination. True or not?

[deminimis]

The only way to get the crud out is to push the grease out. You fill until you see the grease escaping. The seals are made to allow this. At least that's what I've always been told and have done for the past 25 years. If you don't push the grease out, then there would be no way on knowing its full of grease and not dry. Damnit, now I'm gonna have to go and check on this.

[deminimis]

Here's the first thing I saw on a search (Driveshaft Specialties in Texas):

"Seals in a greaseable U-Joint are designed to let grease out as new grease is added."

[adventureduo]

Originally Posted by jage

Are you supposed to push the old grease out? I'd always heard that overfilling with grease until it came out the seals would weaken the seals or leave them open to more contamination. True or not?

If your doing proper maintenance, just a couple pumps with the grease gun will work. No need to inject so much as to have the old grease come out and expand the seals. I usually just add enough to where i see a slight bit of grease and then stop.

[BroncoHauler]

Originally Posted by jage

Are you supposed to push the old grease out? I'd always heard that overfilling with grease until it came out the seals would weaken the seals or leave them open to more contamination. True or not?

I've heard this when dealing with the rubber boot seals on vehicle front ends (tie rods, drag links,...).


Herb

[myriadmyriad]

Its best not to break the seal. The grease that hangs out can pick up sand etc. As they get older its hard not to push grease out, if you do, wipe it off.
Once the seal is broken I would grease every 3000 miles.



Jeff