Archived Transfer case Problem

[Todd G]

I posted in the 12 valve forum but haven't got a response. Anyone out there know about the internals of the NP241 transfer case. I need help ASAP. I am stuck.

 

[aramsey]

I have a lot of experience with older NP units. I may be able to help. What's up.

 

[Todd G]

I've had the transfer case to the dealer twice in the last year to fix a broken snap-ring on the output shaft. This time I got a grinding noise when shifting into 4wd so I pulled the back half of the case off and found a 4" snap-ring and a small rectangular metal piece stuck to the magnet in the bottom of the case. Upon further disassembly, the gears and all the other parts seem to be in good shape. It looks to me like the snap-ring holds three of the rectangular metal thingees to a floating gear that engages 4wd. Two of the three were still attached to the floating gear. I can't figure out how the metal thingees are held to the gear or what their purpose is. I'm pretty sure that's all that is wrong with the case. All I need to do is put it together now. Any help would be appreciated.

 

[B.G. Smith]

Transfer case

The thingies are synchronizer struts and are held in place by the ring. Does the ring have a bent ear on one end? The ear goes inside one of the struts and the remainder just goes behind the end of the other two struts. I am looking at a manual and it looks like you will have to remove the gear and make sure the inside ring is in place. Also looks like the shifter hub will need to be on the gear to keep the struts from falling out, I have used wheel bearing grease in similar cases to hold small pieces in place while assembling. Like I said, I am looking at a manual, if someone has better info, please reply. bg

 

[Todd G]

Thanks for the info. There are two 4" snap rings so I assume on goes on either side of the gear. I will attemp to piece things back together now.



Thanks again.

 

[JTroiano]

I think GM uses the same transfer case and they had a problem with the rear snap ring popping off or braking due to the inside radius (sp?) of the bearing being to large and you just had to replace the bearing and snap ring to fix the problem. The three pieces you found also need to be re-installed. They fall out because everything slides back when the snap ring fails. Hope this helps.

Jon T

 

[Extreme1]

If the strut tension rings popped out, you either need new ones or you need to bend them open a little. If they do not put enough preload on the struts, they'll fall out again.



The rings should have a tab on one or both ends, I don't recall.



While you're in there, make sure the plastic (YES, PLASTIC!) wear parts on the shift forks are OK, now is the time to replace them.



The pump is a lot of fun to get back in. There is a trick to it.