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Sealing T-Case/Clocking Ring/Tranny adapter

skidog1us

skidog1us

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Long story short is I swapped out my NP208 for a NP241 with JB SYE and DIY4X ckocking ring. I used the gasket that came with the NP241 rebuild kit and applied Black RTV to both sides of it and sandwhiched it between the ring and tranny adapter. Now I have a very slow leak, more of a drip, between the ring and adapter.

Has anyone else used a gasket in this application or just RTV both inner and outter flanges of the tranny adapter? Guidance is appreciated.
 
RTV is all I use.

On top of that, I've had success stopping leaks like that without bothering to take everything apart. First, make sure you know where it's leaking from. Spray brake cleaner to remove the oil that has leaked and quickly wipe everything down with a paper towel. Then apply some RTV to the joint.

It's not as pretty looking but if it doesn't leak I don't care, just one more thing to think about.
 
Make sure your mounting studs have not worked through farther than they should be. They will keep the ring from seating flat. If that's the case, it'll never seal.

That being said, I recommend a gasket for that spot for guys that have trouble with it. RTV will do the job by itself but a gasket will do it better. Make sure things are getting torqued evenly when you put the ring on.
 
I would probly change out the rear output seal on the trans and the input seal on the T-case.....
 
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The gasket is very thin. I may have to look into the mounting studs depth. I don't recall instructions or torque spec being included with the clocking ring. Would it be possinble for you to email them to me?
 
There shouldnt be any fluid leaking from the seals. Its $20 bucks and about 1.5 hours to replace the seals.
The 700 and 241 are sealed unit's. No fluid should be between the 2. Thats why there is a weep hole.....to indicate a bad seal.
 
Are you sure about that? After reading several posts about clocking a NP208/241 several others have mentioned ATF coming out when removing the T-case from a 700R4/4L80E. Both T-case & Tranny recently rebuilt.
 
The adapter area between the back of the trans and t-case is supposed to be a dry area, no fluid, just a spinning shaft. The trans and the t-case do not share fluid, even though sometimes they use the same fluids. If you have fluid in there, there is a bad seal somewhere.
 
496truck said:
The adapter area between the back of the trans and t-case is supposed to be a dry area, no fluid, just a spinning shaft. The trans and the t-case do not share fluid, even though sometimes they use the same fluids. If you have fluid in there, there is a bad seal somewhere.
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Correct. Either the rear output of the trans, or the front output of the tcase. I would replace both. Like I said, thats why there is a weep hole. To indicate a bad seal.... dont just plug it up with rtv.
 
I have the same problem but my set up is 400/clocked 208. I sealed the $hit out of it last time I put it all back together and it still leaks. With my set up should it be a "dry area" or does fluid slosh around in there?
 
More specifically, replace the trans output shaft seal and the t-case input shaft seal.
 
Ok, not to doubt your guy's knowlegde but I just stopped by the shop next to mine and he has been a transmission rebuilder for 20 years or so and he says the 400 isn't dry where it meets with the transfer case. That is why when the input seal goes bad on the the transfercase fluid starts coming out of the vent on the transfer case. (which happened on my last transfer case because it had a bad input shaft seal). Can anybody verify one way or another?
 
I stand corrected, just removed my 208 to reseal the case halves. The trans does not have a shaft seal and will allow fluid into the adapter area. Designed that way to lubricate speedo gears (in a 2wd app) and gov valve gears. The t-case does have a seal to keep the fluids from mixing.

I hate it when I'm so sure of something, but I've worked on so many things at all kinda melds together, and I end up being wrong. Oh well, at least I'll man up and admit it when I'm wrong. :D
 
496truck said:
I stand corrected, just removed my 208 to reseal the case halves. The trans does not have a shaft seal and will allow fluid into the adapter area. Designed that way to lubricate speedo gears (in a 2wd app) and gov valve gears. The t-case does have a seal to keep the fluids from mixing.

I hate it when I'm so sure of something, but I've worked on so many things at all kinda melds together, and I end up being wrong. Oh well, at least I'll man up and admit it when I'm wrong. :D
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I am the same way, I rarely am wrong but when I am and I realize it, I admit it.
And I was getting ready to say that about the tranny when I saw your last post.
Yes the Tcase should be sealed but you still will have fluid in the adapter area.
The best way I found for sealing the adapter was to use the gasket with a very thin layer of RTV on both sides, put it together but do not tighten too much just snug fit, then wait a few hours then tighten to spec.
It will allow the RTV to dry up when still a little thick so when it is tightened it has some flexibility and seals better.
 
I don't think any 4x4 chevrolet transmission is dry between it and the transfercase. I know for sure that the 700r4 has an actual port in the rear tail area that allows fluid to move from the pan to tail area. If you tilted one back nearly all the fluid from the pan would come out that port.
 
FastMaxx said:
I don't think any 4x4 chevrolet transmission is dry between it and the transfercase. I know for sure that the 700r4 has an actual port in the rear tail area that allows fluid to move from the pan to tail area. If you tilted one back nearly all the fluid from the pan would come out that port.
Click to expand...

As stated above, this fluid is needed for oiling the speado gears in 2wd models and the couplers in 4wd models.
 
Thank you 496truck, Iceman & FastMaxx.

I kinda thought so since the tranny was recently rebuild...Np208 that I removed was rebuild less than 2000 miles ago and a lot of fluid came out of the adapter when I seperated the two. The NP241 I rebuilt didn't leak while sitting on the bench for two months either. I'll pull it back out, check the stud depths & torque on the clocking ring, clean adapter and clocking ring mating surfaces, let RTV set some and reinstall per Iceman's suggestion.

The brotherhood helps again!!!
 
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