I put a Cummins in my '79 F250. I used an Advance Adapter kit to marry the NV4500 to my Ford NP205 transfer case. Last fall I found out the hard way the Ford seal keeps the oil inside the case, but won't keep the oil OUT. My transmission oil went to the transfer case and ruined my transmission. Naturally I didn't find this problem till after I had replaced the transmission.

Does anyone have a part number for a seal that will fit the Ford transfer case that has a double lip like Dodge uses?

 

I talked with Advanced adapters after receiving 1 paper type seal for use on my nv4500 to np273 project. the tech guy i talked with told me to use Toyota sealant to seal both sides of the adapter. I was concerned since the instructions said to remove the seal inside the rear section of the tranny.

I have used the toyota sealant on projects before and it is very good.