I'm am going to start replaceing seals and gaskets on my "New Process" # 205 transfer case on my 1972 K-20 with an 350 automatic.I am puzzled to find that it is leaking red transmission fluid. I always thought that it should have had 90 weight in it. I had the transmission rebuilt back in 1986. I don't know if the guy did anything with the transfer case or not. Can someone advise me what this transfer case should have in it. Thanks, Bud
I have this question too. I am rebuilding my entore truck and had the trans and transfer rebuilt by a shop. Mine also started dripping red fluid out of the speedometer housing while it was laying on the floor. The service guy told me he put a mix of 80/90 and ATF. He swears that is the best thing to do for them. I would like osme opinions on this too.
Your NP205 should have 90 weight in it. I have never heard of mixing ATF with 90 weight. As one is fluid and the other is oil. I would think that the fluid would wash down the oil and cause wear. Vince
I have a gear drive so I am putting 80-90 in mine also. Most of the ATF already ran out the speedo adaptor anyway, they definitely didnt mix. thanks vince. Jay
I learned something yesterday, I contacted the guys at the "High Impact" site from the web. The guy I talked to said that the cast iron NP205 always gets 90w, but that some of the aluminum (newer) case models will take tranny-fluid. He also mentioned that if the rear seal on my 350 tranny was leaking that could be how the tranny fluid got into the transfer case. The way to check that is to remove the "fill" plug from the transfer case, if fluid shoots out then its coming from the tranny. Hope this helps those who need to know.
old post for sure but. I put a NP205 in mine last summer (2014) and after a lot of research I found that GM did use tranny fluid in the transfer case on the later trucks for the less resistance and better fuel mileage. sure glad I did or I would have totally screwed my NEW transmission. there is a seal inside the adapter that I didn't know about and all my transmission fluid dumped into the transfer case. And of course vice versa. All I'm suggesting is check into the fluid type a little farther. Might be surprised https://www.google.com/search?q=NP2...microsoft:en-US:IE-Address&ie=&oe=&gws_rd=ssl
