Hey all, I have a really unusual probably right now. 2000 7.3 Excursion 4x4 with a ZF6 swap in it, brand new transmission, clutch, everything. As of lately i've noticed a slight leak coming from the rear housing of the transfercase, nothing extreme but it slides on down to the bottom of the transfercase enough to be obvious. About two weeks ago I checked the fluid and it was about a qt low so naturally I filled it up to the hole when I couldn't fill it anymore. I put about 200 miles on it maybe a little more and the leak was still present. So today I decided to check the fluid level once again in the transfercase to fill it up before I take it to this ship tommorow and to my surprise as soon as I removed the fill plug probably a 1/3 or a 1/2 of a qt came out real quick. Before hand I had started the truck to let it idle for about 5 minutes after installing some sound proofing mats but never moved the truck itself. I've done a little research and have noticed people saying its the output seal on the back of the transmission but I find it insanely hard to believe thats my case being that the transmission is a freshly rebuilt ZF6. Any and all help is appreciated, thank you.

 

Did you check the fluid in the ZF6? If the seal is leaking, the fluid level in the ZF6 might be low. This would indicate seal problem.

 

I'm going to in a bit once it's all cooled off, does it seem bizarre for that to happen with a transmission that doesn't have but maybe 5000 miles on it?

 

The transmission itself was good to go and full. I can't possibly fathom how theres extra transmission fluid in the t-case when the input shaft going into the trans is sealed off.