So my u-joints have been on their way out for the past year, and I'm finally getting around to take care of them now that the rears took a digger.

First of all, this is my second u-joint in the rear I've done, its always been greased when I do it and supposedly the oil change has been doing it. Once again, my rear most u-joint has 3 posts instead of 4, have any of you guys experienced this?

Secondly, have any of you with the 3 piece drive shaft ever experienced the slip yoke rusting together despite being greased about 3K miles ago? Not even to mention getting the old u-joints out. They come out of the shaft just fine but getting them suckers out of the joint that bolts to the diff... jesus. The BFH isn't effective even with a torch.

Lastly, what is the deal with the basket on the transfer case end of the front drive shaft? It appears to have 2 u-joints in it, neither one of them seem bad with the drive shaft installed but that whole basket seems to move about 1/4 to 1/2 inch. I figure this means both of them joints are shot, but wth is this setup? Is there an easy way to remove it? Anyone ever had that casting break before?

Thanks in advance, just kinda frustrated... but at least this time my truck isn't some strange anomaly, need an exorcist, or intermittent phenomena... just that damn iron moss this time

 

Now, don't shoot me if I am wrong (I am 7000+ miles away from my truck and can't look) but AFAIK what you are looking at is called a Cardan joint, not a U-joint.

Looks like this?

 

Yup, that be the gizmo

 

i believe its correctly referred to as a double cardan,but maybe i'm mistaken. as far as the 3 trunnion ujoints, i would suspect either it didn't get enough grease or a needle falling down during install. third possibility damaged seal during install. i like to spread about 1 shot of grease around the inside of the cup before i install it. using a press or vise also reduces the jarring that can make needles fall out of place. the double cardan is a cheap form of constant velocity joint which tolerates the angles of the short front shaft. the angle of the shaft to joint should be equal and opposite at the transfer case and rear diff. its not possible to do this to front and rear shafts at the same time, so the double is how they deal with it

 

So does it come apart easily? Can I change the joints out of it the same way I would the drive shaft? I just don't know how to handle this and my manual doesnt even mention it.

 

it comes apart pretty much the same. the exception i found on the superduty is that the ujoint nearest the flange must be disassembled first to make enough movement to get the second one apart. I'm referring to the flange that bolts onto the transfer case. i can't recall for certain and I'm not near to the truck for quite some time but as a whole unit some movement might be normal. I would try to isolate one from the other and see if there is actual movement. reassembly can be a little fiddly, the link in the middle should be greased when you reassemble it and then it wants to fight you kind of like trying to push a slipjoint together that was greased while it was extended. some naughty words may be required

 

Thanks! I found the rear drive shaft to be the same way. I'm certain those u-joints are bad because when i'm in 4x4 they howl like no tomorrow, and I was able to get them to squeak just rotating the drive shaft by hand.

Also, funny you mention the slip joint... mine in the rear was rusted together. All the nylon coating had been scraped off and the yoke rusted to the shaft... it took many of swears, penetrating oil, and 'persuasion' for my buddy and I to get it off. I caked that thing full of so much grease hopefully it wont do that again!

 

kind of strange for the slip joint to seize, could put a strain on the transfer case output, and the differential input. once you got it free and clean was it still fairly snug. if its not reasonably snug the shaft won't be fully lined up. or was it just a dirt ridge it had to slide over to come apart. it should move though every time the diff moves up or down over a bump so for it seize??????

 

Well it definitely is snug, with grease in it the only way to really move it is to tap it with a hammer then it slides pretty good... the rust inside the outer slip portion is horrible. Funny thing is though now that I got it all cleaned up and put back together the truck pops when I hit the gas like there isn't sufficient lube in there?