N241 Transfer Case Fix

[StephenA]

In trying to diagnose the clunk I get after an abrupt shift, I ran across an upgrade for the "factory snap ring on the output shaft that is prone to failure". According to the manufacturer, "This common failure generally is not noticeable at first allowing the main shaft to move back and forth eventually causing major damage and expensive repairs to the transfer case. With a broken rear shaft snap ring the main shaft is allowed to move and the oil pump can malfunctions causing improper or no lubrication."
I don't know if this is the source of my clunk, but the upgrade part is a two piece heavy duty collar that bolts on in place of the snap ring and runs about $40, so it might not be a bad idea to install it anyway, if it works as stated.
Is anyone familiar with this product? It's made by Gilly's and is called thr Transfer Case Saver.
If it's a really useful upgrade, maybe the guy will advertise with TDP.
Also, I'm wondering if the clunk I am getting could be a warn out chain in the case. I think my oil "using" problem stems from the forward seal leaking oil into the tranny...
Does anybody know -is it time for a rebuild, or (if my chain is ok) can this seal be replaced without rebuilding? Before removing & opening the case, is there any way I can verify the condition of the chain or other parts that may need rebuilding?
And regarding rebuilt kits, who has the best at the right $? (The guy that sells the snap ring upgrade also sells a rebuild kit with chain for about $300, with expolded views & instruction manual.)
Is this a pretty straight forward job or a tricky one to get right? Just want to know what I'm getting into...
Thanks guys,
Stephen :cool:

Upgrade website:
http://www.drivetrain.com/gillies/Tcasesaver.html

[StephenA]

If someone can correct my topic heading, I meant to type NP241, not N241...
-S

[bnmccoy]

I had the output shaft 'snap' ring snap about 2 or 3 years ago. I first became aware of a problem when I heard a loud ratcheting sound when first taking off from a stop; which would go away once my speed got up above 20-25 MPH. The noise would not occur at all if the truck were in 4-wheel drive.

I removed the transfer case and tore it apart. The large retaining ring on the output shaft had broke allowing the shaft to slide and change position in such a way it was bringing the gear on the output shaft against the synchronizer - this was the noise. A spring had come loose that held three 'things' (don't recall proper name) as part of the synchronizer gear assembly.

I spent less than $20 on parts, just a lot of work for one person and a floor jack.

The rest of the transfer case looked excellent.

I also decided if it ever broke again I would have a split Collar machined to replace it; however, I later found the same device available on the Internet as you did.

Hopefully it will not break again.

I always wondered if I had stressed mine as about six months before it failed I had inadvertently left my truck in 4WD for about 50 miles on dry pavement pulling a 24-foot travel trailer. I use to always put it in 4WD at least once a month when I went down my father-in-laws dirt drive; which is where the travel trailer was stored. I forgot about having it in 4WD. I towed the TT home; loaded; hit the road and did not realize it until well on our way down the turnpike. I guess the normal 'protest' of driving in 4WD on dry pavement went unnoticed since pulling a TT exerts its own stresses.....

Good luck....

Bob

[StephenA]

Thanks Bob. I think the collar is worth it. I did the same 4x4 pavement trip twice without towing & finally decided to rig a 12v idiot light on the dash connected to the 4x4 light below... Did you have to remove the cross member to pull the t case, or did you just back it up & jack it down? The chain was tight after all that?
Stephen

[bnmccoy]

I can't remember for sure if I removed the cross member; but, I'm pretty sure I did. I actually had to stab the xfer case twice as I didn't initially realize that the gasket between the xfer case and tranny was not reversible! I think that gasket was my most expensive part too!

The inside of the transfer case looked good; chain looked fine.

Truck now has 188K miles

[StephenA]

Thanks agaian, Bob. I'm putting mine on the rack tomorrow for a thorough inspection. Say, where did you get your dual t stat cross over? Is there any advantage to it without the HO pump?
Stephen