np241...what the(*(*&))(*$$##

[94bluehd]

New SM FW, Clutch and rebuilt the NV4500, read about that mess here:

http://www.thedieselpageforums.com/tdpforum/showthread.php?t=34301

30mi after tranny rebuild and SM/clutch install the TC started popping into neutral.

I pulled the NP241 apart and this is what I found:

broken spring retainer

worn range shifting fork-worn through the plastic retainers and into the aluminum and had just started hitting the planetary.
Planetary looks great, like new.

a retainer/snap ring was out of it's groove on the outer side of the output.

What do you suppose was the cause? did the snap ring move and allow movement of the shafts to the point of the fork wear and broken retainer? Did the FW/Tranny work have any affect on this? If this was just a coincidence that it happened now, I wish it would have happened 40 miles ago as I was getting ready to do the clutch and found the other mess!!

[Robyn]

Hard to say for sure

There is a very good likelyhood that it was the luck of the draW though.

There should be no real connection between doing the clutch/FW and the T case failing.

Just clean it up good and replace the bad pieces and it should be fine.

Best

Robyn

[trbankii]

Unless you severely manhandled the t-case to the point that the spring clip popped loose from the abuse, I'd agree with Robyn that it was coincidence. I would also say that looks like more than 30 miles of damage, though, and likely had been going on for awhile before you got around to the R&R on the clutch.

[94bluehd]

Thanks for the replies, parts are in the mail. Should have it together this weekend. I am going to be very articulate when i put it back together.

[tanman_2006]

My family has a truck just like yours (Blue, 94, 1ton, srw, 6.5, NV4500, 4x4) not that that matters much, but it did have the same problem with the tcase at around 320k miles, that coulda had something to do with it :D. We put new forks, and other parts can't quite remember, in it after it sat for around a year, works just fine again.

[chickenhunterbob]

Happens occasionally, some talk of it on the off road forums. Some have replaced the snap ring with "Gilly's T-case saver", do a google search...

It's a two piece collar that you cinch on the shaft with allen screws and replaces or eliminates the snap ring, supposed to be a better fix.

[94bluehd]

I put in a TC saver the last time I rebuilt it. The snap ring was interior of that, on the other side of of the output bearing.

[chickenhunterbob]

I put in a TC saver the last time I rebuilt it. The snap ring was interior of that, on the other side of of the output bearing.

So is it that the T-case saver acts as sort of a back up, in the event the snap ring was to fail?

[94bluehd]

No the TC saver replaced the rear snap ring. My problem was a snap ring inside the case. I think it was inside the rear housing on the inner side of the output bearing??? At any rate, it allowed the shaft(s) to move and destroyed the range fork and then the synchro springs.

[94bluehd]

If it weren't for bad luck, I would have no luck at all....

Got it all back together and drove it around town. Pulled the truck back into the shop to fix a loose exhaust and saw the TC leaking along the midline (must have had a space in the gasket material??).

I pulled the TC out again and when I pulled it apart, there were needle bearings floating around?????after only 4 mi!!!!!!!!!!!!

One of the needles got into the oil pump and ruined it but that was it. Turns out the pilot bearing for the mainshaft was either defective and/or I messed it up? Got it all back together tonight with a new pilot and oil pump. Wish me luck everyone, I need it.