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Old 11-22-2020, 03:29 PM   #1
RPBurris
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NP203 Square ring to adaptor plate Question

I posted this yesterday on the 4x4 forum section. Hoping to get some more input. Basically want to verify the proper location of the square O ring. On the adaptor or in the trans? For the record it was in the trans on disassembly as shown.

So quite a few years ago I ordered the new square ring that goes between the transmission and adaptor plate. Like many things by the time I got around to installing it (after it had been apart for a while) the thing leaked like a submarine with a screen door. That was many years ago. A few less years ago I removed the T-case and attempted to fix the leak again. It was better for a while. So today I finally bit the bullet and pulled the t-case back off since I wanted to do it while I had the hump off and before I finished the interior. Below are some photos. I had a thin layer of orange RTV between the adaptor and transmission and grey RTV between the adaptor and t-case. It was definitely leaking ATF and not the 40 weight oil from the t-case. So before I attempt this one last time I figure I would ask the experts here to get some pointers. I would really like to not leak ATF...Below are some photos from the disassembly today. The first 3 photos are exactly as I removed everything after it was cleaned up. The last photo is more of a question mark on if that is the correct way to install the square ring? Thanks for the help!
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Old 11-22-2020, 03:51 PM   #2
kwmech
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Re: NP203 Square ring to adaptor plate Question

Put the ring on the adapter--the other way may cause the ring to roll out of place. I always put a thin film of ulta-black sealer on the ring before bolting it down
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Old 11-22-2020, 04:58 PM   #3
RPBurris
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Re: NP203 Square ring to adaptor plate Question

Quote:
Originally Posted by kwmech View Post
Put the ring on the adapter--the other way may cause the ring to roll out of place. I always put a thin film of ulta-black sealer on the ring before bolting it down
So the last picture is the correct way?
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Old 11-22-2020, 08:17 PM   #4
AussieinNC
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Re: NP203 Square ring to adaptor plate Question

Yes...

If that square ring was inside the case as shown in your top pic, you have found your problem...the ring is supposed to fit into the small lip depression cut into the outside bolt flange....

Your last pic with the ring on the housing is as I install them...a little run of sealant around the ring just before its installed will aid the seal....

Also, it also helps to have sealant under the bolts that secure the casting to the trans output flange....

BTW...I would grab a brand new square ring,,,it may have shrunk sitting around....

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