Dana 44 Pinion Seal Issues

As said, first two pictures show the seal in backwards. The spring goes toward the oil. Are you driving the seal all the way to the bottom of the stepped bore? If not then that is probably your issue. Is the yoke in the first picture new? Looks like the wrong dust shield. Looks like one more designed for a transfer case. I've had to remove them on occasion due to seal to dust shield problems. Especially on new yokes. I don't like to do it, but sometimes necessary.

Fwiw Dana 25, 27. 30, and 44 all use the same pinion seal.

 

SKF 15788 & National 5887V seem to work without issue. All other seals rub or have interference to varying extent. YMMV... Also, the front pinion seal is on a Dana 25, tried the Walcks seal which will work but does rub a bit. Yes I did go through a bunch of seals. Now I know.

 

Glad you got it sorted out!

BTW there is no National 5887V, but there is a 5878V and a 5878 which apply to these axles. The "V" is a Viton seal, and the 5878 is made of nitrile ruber aka Buna-N. Both materials are used for things like seals and o-rings, but National sells the Viton part as a superior alternative, and it shows in the price. The 5878V has a different steel structure too, which may be important in this application where interference is a problem.

Viton seal - More Information for NATIONAL 5778V
Buna N seal - More Information for NATIONAL 5778