CV Shaft popped out

[mason10198]

Yep! driving through some muddy trails yesterday and all of sudden felt like I lost my 4wd... sure enough, the passenger side cv shaft actually came disengaged/out of the disconnect on its own. The disconnect and shaft are both new, less than 3 months old. I had replaced my old 4wd disconnect with an AWD unit from US Powertrain after hearing good things from a few users here. I will admit, I knew there was too much vertical play in the shaft when I checked and wiggled it a week or two ago, but I put off tearing into it to replace bearings. After all, why on earth did the bearings get SO bad that the shaft popped out in 2 months?? The things brand new! I can only assume that after spinning around with a loose shaft like that, that the internals of the disco are presumably jacked and i'm going to need to just replace the entire unit.

Could there be a deeper problem around the intermediate shaft or the front diff causing my brand new disco/cv shaft to screw up like this? I'm going to tear into it today and actually get a look at everything. I'm talking solely off of assumptions and opinions right now... will post pics too.

[DirtyBacon04]

I had an issue with US Powertrain too. The awd sleeve itself exploded after about 6 months of use. Bearings and case were fine though. 90 day warranty only. They may not be as high quality as we were all hoping. I've installed my rebuilt ATP one with a GM sleeve and it's been holding up great.
hmmmmmm

[bljis123]

Damn, I just bought the US power train with actuator. Had good reviews and a ton sold. Damn it!!

Tell me this, did you replace the CV axle when you did the disconnect? Could the splines have been worn a bit from a bad diso?

EDIT: Oh how were the splines on the intermediate shaft?

[mason10198]

Okay, I pulled everything apart. What I found:

Disco side CV shaft has worn ridges from riding incorrectly in the disco
USPowertrain disconnect is full of water, virtually no seal whatsoever between the two halves (sealing you see in the pic is 100% unaltered and right when I opened it), grease is clumpy and hard, parts look okay except for screwed up bearings from the shaft riding incorrectly.
Intermediate shaft is rusty and appears to have ridges on it as well, might have been there before as this is the first time I've really looked at it.

So as far as I can tell, I need a new CV shaft, new/rebuilt disco, AND possibly a new intermediate shaft?? Does that even come out without removing the front diff? I still dont see where the problem came from in the first place anyways. All of the bearings are in good condition wear-wise, it just looks like the shaft was riding lower than its supposed to, and wore into them. Like something about the disconnect maybe isn't aligned properly? Or is it more likely something to do with the intermediate shaft instead? I guess another possible explanation is simply that the shaft never got fully inserted into the disconnect when I installed it... but I doubt it.

[mason10198]

Damn, I just bought the US power train with actuator. Had good reviews and a ton sold. Damn it!!

Tell me this, did you replace the CV axle when you did the disconnect? Could the splines have been worn a bit from a bad diso?

EDIT: Oh how were the splines on the intermediate shaft?

Yes, I replaced the shaft with the disconnect. I did not pay any attention to the intermediate shaft, so I don't know exactly what condition it was in at that time.

[bljis123]

How long ago was install? just curious based on how it looks inside...

Great pics!!! Yeah not good that all that mud and water got in and you can see the wear of it not sitting right. With a brand new disco and CV that makes no sense that it did not go in super tight and you have to play with it to get splines perfect to slide in. hhhmmmmm this concerns me with my part coming in next week.

WOW!!! The intermediate shaft looks awful. I believe the shaft has a Cir clip IIRC...

[mason10198]

Put the new shaft and disco on less than 3 months ago, probably somewhere around 8-10k miles I guess. Yeah, I guess my intermediate shaft doesn't too great, but does that just come out and pop a new one in? I'm guessing its NOT a cheap part. I'm looking right now and can't even find anything yet.

[bljis123]

It does come out. I am trying to find the thread where someone said it has cir clip holding it in. Looking.....

[bljis123]

It does come out. I am trying to find the thread where someone said it has cir clip holding it in. Looking.....

[mason10198]

I found a couple on trailvoy saying either grab it with vise grips and pry it out from the disco side, or beat it out from the disco side, but I cant see a way to do that as the carrier in the diff is in the way.

[bljis123]

Found it on this site:

10. Remove intermediate shaft. I bought a slide hammer for this purpose and expected a fight. I didn't need it. I screwed one of the bolts that holds the PCM into the hole in the shaft and pulled. The shaft came right out. My inner seal was worn and leaking. The new seal had a bit more grab to it, and I needed the slide hammer to get it back out.

[navigator]

I think I have a spare shaft lying around if you need it. You can have it for the cost of shipping.

[larryk]

No circlip on intermediate shaft....just splined on both ends.

Unreal how rusty yours is. I've seen tons of these in the boneyard and none are rusted like that

[mason10198]

I just pulled the thing out with no effort at all... just grabbed it with my hand and it slid out. I'm about to grab a brush and clean it up to see better, but here are some initial pics.

[mason10198]

I think I have a spare shaft lying around if you need it. You can have it for the cost of shipping.

CV shaft or intermediate??

[Trail X]

Strange that it affected your intermediate shaft. I've never seen one of those worn. The only guess there is that your needle bearings went bad - normally due to improper grease or water incursion. You ever submerged that disconnect? Something like that would do it, and cause your intermediate shaft to rust like that.

Its very possible that your CV shaft didn't fully seat. Sometimes they can be a pain to get fully seated - and they give you a false sense of being seated. Normally, I tamp mine in using the plunge joint of the CV shaft. You'll hear a tonal change when you get it fully seated - but I normally give mine a good 4 or 5 more taps. Did you grease the splines before inserting the CV?

[larryk]

That shaft is toast, and based on the wear, it looks like the output bearing on your differential is bad too. I hate to be the bearer of bad news, but if this was my truck, I'd be pulling that diff to rebuild it. Did you check the fluid in it to see if there is any water in it? It's not right it just slid out too...

[mason10198]

Strange that it affected your intermediate shaft. I've never seen one of those worn. The only guess there is that your needle bearings went bad - normally due to improper grease or water incursion. You ever submerged that disconnect? Something like that would do it, and cause your intermediate shaft to rust like that.

Its very possible that your CV shaft didn't fully seat. Sometimes they can be a pain to get fully seated - and they give you a false sense of being seated. Normally, I tamp mine in using the plunge joint of the CV shaft. You'll hear a tonal change when you get it fully seated - but I normally give mine a good 4 or 5 more taps. Did you grease the splines before inserting the CV?

Never completely submerged it, but I can tell you it's been that rusty since the first time I ever got in there and saw it. I just now cleaned it up with a wire brush and it was pretty much all surface rust, only a few tiny pits in the surface. Masked the splines and threw a thin coat of rattle can on it just to slow that down. I guess you're right, I didn't do anything to get that CV shaft in except shove it in by hand and call it good. I'll be doing a better job of that from now on.

That shaft is toast, and based on the wear, it looks like the output bearing on your differential is bad too. I hate to be the bearer of bad news, but if this was my truck, I'd be pulling that diff to rebuild it. Did you check the fluid in it to see if there is any water in it? It's not right it just slid out too...

The pictures make both ends of the intermediate shaft look bad, but there is only physical wear on the disco end of it. The diff end is fine, and I can confirm there is no water in the diff fluid. The fluid in it is also relatively new, within the past 8 months. I slid the intermediate in and out a few times and there were no pops or engagements of any kind, it came out just as easy every time.

[larryk]

So that shiny band on the diff end, where the bearings ride, isnt worn? I guess if there is nothing you can feel with your fingernail, just give it a quick cleanup with a scotchbrite pad, and you would be good to go. Somewhat concerned that you can insert and remove the shaft that easily though. Literally every intermediate shaft I have ever dealt with on these trucks is a tight fit in the diff....where you need at least a bolt in the end of the shaft and a pair of vice grips to pull it out.

Was your truck, perhaps, a flood salvage vehicle at some time? That's about the only way I can see that shaft getting so rusty.....as, while it isnt in a sealed cavity, the crossover tube in the pan is a fairly tight fit to the disco and tne diff.....so water incursion through normal use would be rare? Even going through a stream axle deep wouldnt necessarily get moisture in there sufficient to cause that much rust?

[mason10198]

So that shiny band on the diff end, where the bearings ride, isnt worn? I guess if there is nothing you can feel with your fingernail, just give it a quick cleanup with a scotchbrite pad, and you would be good to go. Somewhat concerned that you can insert and remove the shaft that easily though. Literally every intermediate shaft I have ever dealt with on these trucks is a tight fit in the diff....where you need at least a bolt in the end of the shaft and a pair of vice grips to pull it out.

Was your truck, perhaps, a flood salvage vehicle at some time? That's about the only way I can see that shaft getting so rusty.....as, while it isnt in a sealed cavity, the crossover tube in the pan is a fairly tight fit to the disco and tne diff.....so water incursion through normal use would be rare? Even going through a stream axle deep wouldnt necessarily get moisture in there sufficient to cause that much rust?

Yeah, I can't feel anything on that end, it just LOOKS like there should be wear there. I'm not terribly concerned about it going in and out easy, considering once you bolt the disco on the other side of it, it's not going to move. I'm also not too worried because I'm going to regear at some point once I have a rear axle, gears, locker(s), and some rear suspension components.

We thoroughly checked out all the history paperwork before we bought it and there's nothing about salvaged or damaged on there. I'm not sure how it got so rusty either, but as far as I can tell, moisture hasn't caused any major problems. If it's getting in through the diff side, I'll rebuild it later with the gear change. I'm running 33's and I've never put it through water more than an inch or two higher than the center of the wheel. Granted, I do have a little too much fun with the throttle when I plow through stuff like that, but that shouldn't really make a difference.

Last night I ordered bearings and seals to rebuild the disco, and an outer CV seal for the diff. Should be here saturday. I'll get that all put together with a new CV shaft and it should be good to go. I would put in a new intermediate shaft, but the cheapest one I can find is $200 bucks used on ebay. I DO have a 100k mile 4wd TB in the backyard that I bought recently for parts, I could pull it apart (all ive broken into so far is interior), if its worth all the work to get the shaft out. Should I break in there and get it or will this shaft be good enough?