I've noticed since installing the 4:1 gears in my NP231 that I'm getting quite a bit of fluid loss.

My findings so far: It's very hard to pinpoint exactly where the fluid is coming from, but it is NOT coming from a leak in the case halves or on the tailcone. The case only blows fluid when the t-case is engaged. In other words, driving on the street in 2H doesn't produce fluid loss.

My suspicion is the vent tube. Anyone else having this problem? I really don't want to pull this case again. My idea is to extend the vent tube and put some sort of filter on the end to store the blown fluid, allowing it to drain back into the case via gravity.

Thoughts? Solutions?
Dion

I have responded to several people concerning fluid purging from a np231 with a Tera 4-1. Most of the time you have fluid purging out of the vent it is when you are in 2wd high. It has to do with the case building up too much pressure and Tera does not have a deflecter piece of metal by the vent hole like the factory case does. Tera will supply a piece of tubing that will deflect the fluid from the hole, but you have to pull the case apart to install it. They say they have this problem with a small amount of cases. I have used there quick fix and I have put a clear fuel filter in line and I still use a bottle as an over flow. I suspect the when you are in 4 wheel drive the fluid is being flung over the vent hole in the case and it is pushed out because of the pressure. I would also check the o-ring on the speedo assembly because they are known to leak. If it wasn't such a PITA I would have exchanged the 4-1 a long time ago.

My Jeep leaks some ATF from time to time. I thought my problem was in the T-case after installing the Tera-Low but the t-case isnt low on fluid. The Automatic tranny is the one that gets low on fluid so im figuring its the trans. oil pan gasket. Maybe one of these days I'll actually fix it and stop talking about fixing it :D

Yep. The Teralow loves to blow ATF through the breather hose. To solve the issue, go get a fuel filter and about 4' of hose. Run the breather up the firewall and pop the fuel filter on the end of it. If it blows past the long hose, it'll collect in the filter and drain when it cools.

Tera MFG swears its normal. I had that problem for the 20k miles I had it. Now I got atlas and no more blow by.

I have the same problem w/ my Atlas - coming out the vent tube (attached to the rear of the engine head). I called AA and they indicated that TJ vent tube has a tendency to kink...restricting the release of pressure...allowing a build up and fluid loss. Not sure if that's related to your problem, but i'm in the process of replacing the stock vent tube...so we'll see.

Thanks all for the input. Seth: I'm going to try your option first (that's what I was thinking of doing) and see what happens.

Thanks again.
Dion