Hi, my truck is stored for winter. I need to rebuilt my trans. this spring cause last autumn I had a leaking problem at the inspection cover. The trans. shift Ok but in O.D I felt a little slippage .   I was thinking of an oil pump seal or maybe the converter????   If someone can help.   47re transmission. just been rebuild 2 years ago by me but had a problem with a hose to the cooler. It disconnect and lost all the oil. After that the trans. run fine for about 1 month until I work on adjusting TPS and got this leaking at the cover!!!  the shift become more strong like 1-2.  like a shift kit after TPS adjust and before the leaking problem .. .    I install a transgo diesel kit  in my rebuild 2 years ago!!

What you think???                  Sorry for my text and my english, I'm not so good..   Try my best

Thanks  Francis

And new single disc converter at same time than the rebuild

Is it engine oil or trans fluid?

Trans. fluid

 

The seal on the front of the trans between the tc input and the trans can tear. 

 

could also be the pump seal.  

 

only way to know is to tear it apart.

No matter how you want to slice this you going to pull the transmission down and inspect the seal and replace it. But I will make mention of the possibly of input shaft bearing issues can do this too. What will happen is you'll replace the seal and get just a few days to maybe a week and the seal will leak again. So this is another possible problem too.

Thanks guys!!  I'll need to check it and rebuild it this spring...  Only thing I don't understand is why it's slipping in O.D.?   Cause I lost a little pressure and the OD clutches slips..     I remember that I had a little lost of line pressure.  It was around 110 cruising when OK but now around 100 psi

I'm skeptical of single disc torque converters. I don't think they can handle the torque from a cummins, there just isn't enough friction material/surface area. If your line pressures check out/valve body is good, and your overdrive unit was recently rebuilt, I would bet on your TC for the slipping issue. 

Yea OD is when the TC is working the hardest.  

 

However if the pump seal is leaking and you are bleeding pressure you might notice slipping.

Yeah was thinking of pump seal or TC cause in OD its supposed to be lock. By my remembers the TC lock but little slipping in OD ....    Don't know what can cause the TC to leak..   if it's the problem!!