NP208 Rear Housing Issues

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usar17

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So I had to take the rear output housing off my T-Case to swap the speedo gear on the shaft. While I had it off I installed a new rear shaft seal.

Reassemble brought new problems. Wiped it clean, ran a line of RTV around where the housing meets the main case, and bolted it back on. Let it sit for an hour then went to slide the slip-yoke back in and to fill the case...but....Had a hard time getting the slip yoke back in.

Mistake #1: As a man i just used a hammer to get it in lol then filled the case. After an hour I noticed it was leaking around the lower half of where the Rear Housing meets the main assembly. So I took it back off and tried again. Same problem

So questions are:
1. Thought that could have made it so hard to get the slip-yoke in? It passes through the new seal fine then seems to stick.

2. Leak Cause? Not enough curing time for the RTV? or bc of the slipyoke issue?

:help:
 

crazy4offroad

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Is the bolt pattern of the tailshaft cover symmetrical or asymmetrical? If symmetrical pay attention to the oil galleys/ports and make sure they are all aligned. Also did the tailshaft assembly slip out (rearward) any? If so, some roller bearings may have slipped out from where they belong causing the slip yoke to not go in like it should.
 

usar17

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It only bolts on one way. The housing slides off to the rear leaving the output shaft showing. When I get Time this week i was planning on looking at the bearings and the bushing(?? ring between seal and bearing). IDK if something may have shifted or bent that is causing the slip yoke to no longer slide easy.
 

usar17

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attatched are a few photos of the tail housing. I bend the rear seal being stupid just now :crazy:

The rear ouput shaft is suppose to be a little loose when the housing is off correct? I'm assuming the bearing in the housing is what lines it up for the slip yoke.

All i can see is some minor rubbiung on the collar just behind the rear seal. Thoughts?
 

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usar17

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...also found a hole on the top of the housing on a fluid valley. Just above where the speedo attaches. Should a vent tube be there???
 

crazy4offroad

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With the tail housing off, try sliding the slip yoke onto the output shaft and see if it hangs up at all. If not, try to slide it into the tail housing and see if it hangs up. That would help track down which part it is having trouble going onto/through. As for the hole in the housing, if there's no other vent tube on the t-case that is more than likely going to be where your vent tube goes. Also I noticed your speedo gears on the output shaft, do you think that could have been interfering with the tail housing going on? Did you remove the speedo adapter before putting the tail housing on? Just throwing ideas out.
 

usar17

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Slip yoke fits in housing fine. Slip yoke fits on output shaft fine. It seems to be that when the housing is on the shaft is only when the slip yoke is tight to get on. I wanna try without removing the speedo drive gear from the shaft.
 

dirtroadoutlaw

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Something didn't go back in correctly. That slinger/pump dealeo might be backwards or misaligned. That's the likely culprit. It all has to go in just so as you lift the shaft to line it up. That stuff only goes one way. Also, you have to clean the hell out of the bolts & threads then use sealer on them too. PAY ATTENTION to the type of sealer you use because the fluid will dissolve regular rtv and cause you problems. Read your labels. I can make a short video demonstration of how to do this if you need me to. I have one on the floor at my shop waiting to get built.

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MrMarty51

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Something didn't go back in correctly. That slinger/pump dealeo might be backwards or misaligned. That's the likely culprit. It all has to go in just so as you lift the shaft to line it up. That stuff only goes one way. Also, you have to clean the hell out of the bolts & threads then use sealer on them too. PAY ATTENTION to the type of sealer you use because the fluid will dissolve regular rtv and cause you problems. Read your labels. I can make a short video demonstration of how to do this if you need me to. I have one on the floor at my shop waiting to get built.

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I find that no. 1 Permatex,in the squeeze tube,works best for sealing threads on just about everything I`ve ever worked on.Works real good to coat the outsides of steel shelled seals too.
I replaced the rear output shaft on My 93 GMC 1500,it leaked,around the outside of the seal,pulled the seal,discovered that I had scored the housing when removing the old seal,dressed it up a bit with emory,coated it liberally with the no.1 Permatex,coated the seal,no more leakey.
 

Beendown1

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Speedo gear

Make sure the speedo gear isn't refersed. The flat side goes toward the transfer case. Having it reversed will cause a small gap
 

Maaac1789

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This is a 4-1/2 year old thread, but did you ever figure this out? I'm having the same problem
 

usar17

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I ended up getting a newer one when i swapped my whole driveline out. Make sure youre tightening the bolts in a cross pattern. Only thought i ever came up with was that tcases need assembled on a desk where driveshafts and trans output shafts arent effecting the tcase shaft angles. Lol idk. Isnt too hard to pull the transfer case and rebuild it. Few small parts, seals, and should be good. Best of luck

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