And here: www.discovery2.co.uk/Factory Diff Lock

 

I agree 50k seems awfully short for a shaft to fail, but I wouldn't risk it.

2001 was the last year with a CDL. So unless the transfer case has been replaced in your truck you do not have one in your '02.

If you haven't rebuilt a drive shaft before, I wouldn't learn on this one. I've previously rebuilt several to include one aftermarket D2 front shaft, and the factory shaft on mine was pretty damn difficult. It's not the u-joints so much as the centering ball, which is a royal pain to extract.

Short of rebuilding it yourself, probly the cheapest way to go is pull the shaft yourself, take it to a drive shaft shop for a rebuild. Like I said, triple check they know to replace the centering ball. I'd guess that will save you a good $100 off the cost of buying an aftermarket shaft.

 

So my '02 does not have the diff lock on the hi/low selector; i'll have to search for the nipple tomorrow.

So if i don't have the nipple, which means i don't have a locking diff, does that mean i should NOT drive it / can't drive it without the front drive shaft in?

 

If that's the case you cannot drive it without both shafts.

 

ok, i'll look for the nipple in the morning.
hopefully it does, and i can figure out how to ensure it does engage (and isn't frozen from years of non-use)...
or i hope my local NAPA has one in stock and i spend $450 on a new one cause it's my only quick option...

Thanks again all for your knowledge and thoughts.

 

So after feeling around on top of the transfer case for the bolt, i'm coming up with nothing...

So a little last piece of help/advise would be appreciated just for clarification. The nipple should be almost at the very front of the tranny case, where the drive shaft bolts in like in these two pics, correct?




if that's the case, i'm 99% certain i'm SOL there - as mine is completely flat...


so the next questions would be, what am i looking for as visual evidence when i'm inspecting my drive shaft to confirm it is the failure point? here are a few pics of the U joints, two rear and two front. My novice eye doesn't see anything that screams "failing"...

Front drive shaft rear U joint:
https://drive.google.com/file/d/0B0n...it?usp=sharing
https://drive.google.com/file/d/0B0n...it?usp=sharing

Front drive shaft forward U joint:
https://drive.google.com/file/d/0B0n...it?usp=sharing
https://drive.google.com/file/d/0B0n...it?usp=sharing


Thanks again for all of the help and advice!

 

"History and additional details:
i had the drive shaft replaced (with OEM) about 4-5 years ago, and probably have about 50K miles on it since it was replaced."

So it sounds like you got a non greasable stock shaft so it has not been regreased in any way. I'll bet on that as your problem. One needs to remember that for every mile you drive these shafts spin very fast and when you couple that with the heat of the Cat and other conditions those roller bearings can fail faster then you think.

 

This is close to pure guess work, but based on those pictures, I think your centering ball is failing.

The way these shafts work is that back joint is called a double cardan. A double cardan joint uses a spring loaded device between the two ujoints to effectively put an arc in the shaft. So, when you have the shaft out of the truck, it holds a constant bend just like it does in the truck.

To my eye, yours looks like it's too straight, so I suspect the centering ball has failed and is allowing the cardan joint to flop around. In time, this will shred one of the back ujoints and possibly damage the shaft itself until the assembly comes apart and smashes your tranny.

The way you'd check is pull the shaft and move the assembly around feeling for looseness in the joints themselves and checking to make sure the cardon joint maintains a constant angle. It'll flop around, but it'll flop back into the same angle and if you try to straighten the shaft it'll put itself back at that angle.

 

IF you never have greased your new drive shaft in 50K miles than this may be a sign.

I would at least grease it now and see if that helps.

But Dr Mordo is right.
Quit driving it.
Thump means failure is impending and it will cost you a lot more to deal
with damage from a dropped drive shaft when you are on the freeway.

 

so after an hour of laying on my back and only getting 1 nut removed, i've determined i need some new tools to remove these (what is accurately described as "lead soft") nuts. A socket and breaker bar only fits on like 2 of the 8 due to clearance, and reaching with two standard box wrenches seems a little difficult too.

Any suggestions on best tool(s) for the job given the tight space? I'm thinking a short and long ratcheting 6pt wrench, but if there are better options, i'm open to them too... this is going to be a painful few hours just to remove these bolts without stripping them...

again, thanks for the advice!