So I'm making a repair on my truck and I notice the ujoint on the front shaft at the front housing is pretty bad . I buy 2 ujoints and after I get the shaft out I see there are 3. So I just sent the wife to autozone. Now as I'm taking these ujoints off the shaft , I see in between the to rear ujoints that attach to the transfer case , thier is some kind of bearing?

What is this , and I'm assuming I should also replace this? It came apart into 2 peices after removing the furthest rear ujoint.

 

Centering ball, keeps the double cardian centered. There is a spring behind it, and it is serviceable, not all parts stores carry it. I just recently got a whole new rebuilt shaft for $250 ish at rockauto, wasn't much more then 3 joints and centering ball kit.

Fwiw I have had zero luck with any Autozone ujoint for after a year. Napa was a little better but the factory spicer non greaseables keep on going. Still have a few of the OE joints on rear shaft at 273k on my 98.

 

Cool thx!

 

Second what gorms said....I got spicer non zerks from the local driveline guy...my Napa guy would've told you about the whole mess and saved you a trip....he actually sent me to the driveline guy so it would save me time and money.

 

Given how it sounds like this is the first time you've seen a double cardan joint, I HIGHLY suggest taking it to a driveline shop. The DC joint can be complicated and its nothing you want to get wrong. Especially since you have an '02 which means that most likely your truck is a non-CAD axle which then means that the front driveshaft spins full time. If that DC grenades then it takes out everything around it. Ask me how I know.

 

I posted a question on "the other" forum that I'll repeat here.

With all the controversy about difficulty in lubing the Cardan joint, how often do they actually fail?

Can ANYONE share their experience of one actually failing due to lack of proper lubrication?

 

Get rid of your center disconnect and keep your front end live. Your u-joints and splines will thank you for it.

 

That would be more dependent on whether or not its a full time 4wd or part time 4wd. Because on a part time system the front driveshaft hardly spins, even while driving along the freeway. But on a full time system in 2wd the front driveshaft is always spinning at road speeds along with the rear driveshaft.

I personally prefer a part time system.

So therefore it would be obvious to say that a double cardan joint would wear out faster on a full time 4wd system. But.....that said, if quality non-greaseable joints are used and good quality synthetic grease is used upon assembly then the odds are that even on a full time 4wd system you'll only have to look at the front u-joints about as often as the rear u-joints. Which can be quite a long time.

So in point, even though people LOVE the ability to squirt grease in the u-joint, dont get greaseable u-joints and dont get cheap ones either. Spicer is the best. And lastly, even if you can grease the u-joints you cant grease the center ball.

 

" And lastly, even if you can grease the u-joints you cant grease the center ball."

Ah. but that again points to my question. The lube point on our front axle Cardan joints does lube the center ball, but not the needles in the u-joints. My truck now has over 116K miles and, though I've tried to lube it a number of times I think grease actually got into the joint only a few times. It has a full time system so the shaft is constantly spinning when the truck is moving. So far, knock wood, there hasn't been any indication of undue wear on front , or rear joints.
You suggest that yours failed. Was it the DC itself, or the u joints?

 

As long as your '06 isnt lifted you'll most likely never have any reason for concerns. There is sooooo much misunderstanding of what a u-joint needs in order to last, and greaseable u-joints are high on that list. They simply dont need that kind of constant attention and in reality the non-greaseable u-joints have far better sealing caps which will not only keep the grease inside doing its job but those triple lip seals will keep water and debris out as well. Greaseable u-joints have weak single seals in order to allow greasing them and therefore those weak seals allow contaminates to easily enter.

Front u-joints are fine spinning at road speeds. Whether or not they should usually comes down to fuel mileage from drag or if there's a lift involved. Because the steeper the running angles of the u-joints, the faster they wear out, and they can vibrate.

To answer your question about my experience with a failed DC joint..... Well as the story goes, it was a long time ago and I had just purchased a used "lifted" 4wd truck from someone. I had no idea how shot the front u-joints and DC joint ball were either. They were dry and totally worn out and the lift had the DC housing tabs touching as it rotated. Since it had greaseable joints, I'm sure the reason the joints were so bad was because of a combination of cap grease escaping over time and water intrusion. Nonetheless, while cruising down the freeway at about 60 mph, without warning the driveline began to violently vibrate. Before I could come to a stop the DC joint exploded, which of course caused the front differential pinion to continue turning the driveshaft which had it whipping around under there, beating dents in the frame, hammering the underneath of the cab, knocking the exhaust off, and cracking the transmission. It was all bad..... But what it did do was put me in the position of learning a tremendous amount about drivelines and how to build one for a lifted high HP 4wd truck. That was back before internet was such a useful tool too.

 

Both my trucks have a grease fitting for the center ball.
The reason I keep the front end live, is to stop premature wear. Either from condensing water or constant pounding. I have paid the price for letting the front end sit idle. Both in driveshaft repairs including the splines and having to rebuild the front differential because of a lack of lubrication and water intrusion. The solution was to let it run, keep things moving and lubed. Centrifugal force counter most of the abuse placed on an otherwise idle driveshaft. Even though your front end is now live, it is still disconnected through the transfer case when in 2wd.

 

My apologies as I misspoke. I intentionally built mine without any grease zerk's and wasn't thinking when I said you cant grease the ball.

As for an "idle" driveshaft, I cant imaging that being an issue since they do turn. Just really really slowly while cruising down the road. I've never had to deal with any of those issues you mentioned on a part time system. But I guess there's always different scenarios.