CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

NP241 vent

Justin Fleming

1/2 ton status
 Premium
Joined
Aug 24, 2005
Posts
924
Reaction score
48
Location
Oxford MI
On the top of the NP241 there is a little swiveling barb fitting which I beleive woudl be the breather. Where shoudl this be hooked up to and or where should it be routed?

thanks
 
Probably no farther than that. I believe you'd have a plastic thing there which acts as a breather cap.

If it's just a hose barb, stick a short section of hose on it with an axle breather, call it good.

Or if you plan on playing U-Boat command and doing water crossings, run a hose to a real vent up above whatever water line you intend to handle.

-- A
 
On my 89 blazer the vent house from the NP241 goes up to the radiator support and almost to the hood line along with the diff and trans vent lines.
 
so on my test run today, for some reason when I got back to the hose I noticed a bunch of trans fuild on my nicely cleaned and painted tcase. So after looking around it looks like it was blowing out that hose barb. What would cause this? The tcase was not over filled.

Now I am pissed as I have a oil messing again..... back to the cleaning....
 
If the input seal on the t-case goes bad it will allow trans fluid to enter the t-case and overfill it and then it will start blowing oil out the vent tube of the t-case. Easy check is to have the vehicle on level ground and pull the fill plug (if oil comes pouring out the input shaft seal is bad).
 
If the input seal on the t-case goes bad it will allow trans fluid to enter the t-case and overfill it and then it will start blowing oil out the vent tube of the t-case. Easy check is to have the vehicle on level ground and pull the fill plug (if oil comes pouring out the input shaft seal is bad).


I did check this when it was hot and nothing came pooring out. Tcase was just resealed....
 
I did check this when it was hot and nothing came pooring out. Tcase was just resealed....

Well did you check it or reseal it? There is a double wide double lip seal on the input and it is very hard to find so there is the option to install 2 smaller (thinner) seal back to back opposite of each other to achieve the same results. If a new seal was used and only 1 "thin" seal this is your problem.
 
Well did you check it or reseal it? There is a double wide double lip seal on the input and it is very hard to find so there is the option to install 2 smaller (thinner) seal back to back opposite of each other to achieve the same results. If a new seal was used and only 1 "thin" seal this is your problem.

I will have to take this info to the guy who resealed the unit....
 
Well did you check it or reseal it? There is a double wide double lip seal on the input and it is very hard to find so there is the option to install 2 smaller (thinner) seal back to back opposite of each other to achieve the same results. If a new seal was used and only 1 "thin" seal this is your problem.

If the seal was the issue wouldnt I find the transfer case to be over full? If so than the seal is not the issue as the level is just below the top sight hole....
 
Top Bottom