NP 241c transfer case leak

paulmj

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#1
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MAKE:Chevy
MODEL:K1500
YEAR:1996
MILES:
ENGINE
:5.7
DESCRIBE ISSUE....Chronic leak transfer case at yoke/driveshaft. Leaks when driving or sitting still and slings AT fluid under vehicle. Changed output shaft seal and did not fix leak. No significant play with driveshaft. Small fluid soft ball sized stain overnight seems to come from yoke where it exits rubber seal. Any help is appreciated.
 

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billr

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#2
That is a very odd-looking seal there, I'll have to do some searching to see if I can find a picture of just the seal.
 
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#3
Got a lift kit causing quick seal failure? Is the seal the wrong one...oversize where the inner seal lip contacts the slip yoke? Has the tension spring gotten knocked off the inner seal? Do you have the trans in Neutral when checking for "significant play" due to worn yoke or bushing sleeve? Is most of the leak actually from the center of the yoke next to the u-joint?
 

paulmj

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#4
I'm not sure about the lift kit question. I wondered about the lift effecting the drive shaft angle and causing vibration and eventually causing the leak. I bought the seal at advance after looking up correct replacement so I think it is correct size. I never checked the tension spring at inner seal. I do not have the trans in neutral it has been in park but I will check in neutral as soon as I finish with my other repair (it is on jackstands with both front wheels off). Most of the leak comes from yoke itself near the seal and not near the u-joint. That's why I thought changing the seal would be a simple fix.
 
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billr

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#5
I finally looked at some diagrams of the NP241C. What I am seeing in the picture posted is that the tail-shaft bushing, that the yoke rides in, has slipped out a lot and no sign of the seal being there! You said you had replaced the seal, can you give me a picture of it or a link to one? I hope I'm missing something here...
 
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#6
billr, the seal has a large black rubber 'wiper' attached on it. Perhaps that is what you are seeing?
 

billr

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#9
Sorry about the bogus reply above. The auto-inclusion of the previous post in a new reply is annoying me more-and-more...

No, that is not what I am seeing in the photo posted earlier. Does nobody else see a sharp-edged object with a hole in the side protruding from the tail housing?

Edit: If you haven't blown-up that photo for a good look, do so now...
 
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#10
Bill, I see a drop of reddish fluid hanging "at the center" of the dust cover part of the seal. It matches the drop of reddish fluid hanging on the yoke by the u-joint bearing cup. Camera seems to shooting nearly vertical. (up)
 

paulmj

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#11
Maybe it is a reflection from the light I was using. I could try to take a better pic tomorrow.


Sent from my iPhone using Tapatalk
 

billr

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#12
Don't bother, I think I can see it now. I can believe that "hole" is an oil drop, and I think I can see a bit of taper along the length of the seal boot. With a little bit more imagination I can see the metal flange of the press-in cup and a hollow between that and the rubber boot. Thanks for bearing with me, folks!
 

nickb2

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#14
My Gf wanted for me to post a pic. I said no.

Me with jonny walker and a yellow fender and a cig hanging out of my mouth. "Not really the shyte I want posted all over the planet."!!

I think the photos had one of my balls hanging out. I cracked the phone and threw it in the garbage.