salans7 Posted September 8, 2019 Share Posted September 8, 2019 On another subject. While removing the transfer case, I noticed near the fill hole its embossed "ATF Only". Its an NP208. So, I pull the drain plug expecting ATF, and gear oil comes out. I remove the tcase from the transmission and there is nothing, no seals separating the tcase fluid from the tranny fluid. Of course, the 4 speed uses 80-90. So I assumed Id fill everything back up with 80-90. Why would the tcase say ATF only? There is no way you are going to keep ATF out of the transmission case if you fill the tcase with ATF. There should be a seal around the output shaft of the transmission, keeping gear oil in. There should be a seal on the input shaft of the transfer case, that keeps the ATF in. The extension housing that connects the two should stay dry. However if both seals fail, I guess the possibility is there for the fluid to mix. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 8, 2019 Share Posted September 8, 2019 There should be a seal around the output shaft of the transmission, keeping gear oil in. There should be a seal on the input shaft of the transfer case, that keeps the ATF in. The extension housing that connects the two should stay dry. However if both seals fail, I guess the possibility is there for the fluid to mix. Ray - Shaun is right. 80/90 in the tranny and ATF in the t-case, and never the twain should meet. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted September 8, 2019 Share Posted September 8, 2019 Bill, Shaun, Jim and Gary, Thanks for the advice and opinions. Gary, I think I will follow the factory advice as you have. Jim, thanks for calling me out and keeping me on my toes. Im not a degreed engineer. Two year CAD degree, but I do work circles around some "degreed" engineers. The clutch was replaced in 2004 by the previous owner. I am assuming the throw out bearing was replaced then. The pilot bearing was in good shape, but I replaced it and the RMS anyway. I dont think I want to debate on throw out bearing longevity, and how to maximize it. Im going to do what the factory suggests. Ray, I absolutely agree, you should follow the FSM. :nabble_anim_rules:RTFM!!! So, the bearing is 15 years old... Just like the pilot bearing and RMS it's WAY too much labor to get in there for the $20 you'd save not replacing them. And, like many other things, it's only new once. Link to comment Share on other sites More sharing options...
Ray Cecil Posted September 8, 2019 Author Share Posted September 8, 2019 There should be a seal around the output shaft of the transmission, keeping gear oil in. There should be a seal on the input shaft of the transfer case, that keeps the ATF in. The extension housing that connects the two should stay dry. However if both seals fail, I guess the possibility is there for the fluid to mix. Shaun, I guess that is what threw me off. When I removed the tcase, gear oil came out of the housing between the tranny and tcase. Then, when I removed the trans, gear oil kept coming out the rear. I assumed it was all the same. So, I have a bad transmission output shaft seal leaking gear oil into the tcase......oh well.....I guess im leaving the gear oil in there for now. It works fine. Its chain driven, no clutches I believe. Should be aight. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 9, 2019 Share Posted September 9, 2019 Shaun, I guess that is what threw me off. When I removed the tcase, gear oil came out of the housing between the tranny and tcase. Then, when I removed the trans, gear oil kept coming out the rear. I assumed it was all the same. So, I have a bad transmission output shaft seal leaking gear oil into the tcase......oh well.....I guess im leaving the gear oil in there for now. It works fine. Its chain driven, no clutches I believe. Should be aight. Yes, gear oil usually gets past the seal in the tranny and into the space between the tranny and the t-case. But, not into the t-case. Did you drain the t-case? Did it have just ATF in it? Link to comment Share on other sites More sharing options...
Ray Cecil Posted September 9, 2019 Author Share Posted September 9, 2019 Yes, gear oil usually gets past the seal in the tranny and into the space between the tranny and the t-case. But, not into the t-case. Did you drain the t-case? Did it have just ATF in it? The tcase was FULL of gear oil. Not a drop of ATF came out of it. Link to comment Share on other sites More sharing options...
Ray Cecil Posted September 9, 2019 Author Share Posted September 9, 2019 Yes, gear oil usually gets past the seal in the tranny and into the space between the tranny and the t-case. But, not into the t-case. Did you drain the t-case? Did it have just ATF in it? The tcase was FULL of gear oil. Not a drop of ATF came out of it. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 9, 2019 Share Posted September 9, 2019 Yes, gear oil usually gets past the seal in the tranny and into the space between the tranny and the t-case. But, not into the t-case. Did you drain the t-case? Did it have just ATF in it? The tcase was FULL of gear oil. Not a drop of ATF came out of it. Then someone put gear oil in instead of ATF. Wrong stuff. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 9, 2019 Share Posted September 9, 2019 Looks like the clutch works. Link to comment Share on other sites More sharing options...
Rembrant Posted September 9, 2019 Share Posted September 9, 2019 Lookin' good Ray! Link to comment Share on other sites More sharing options...
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