There were no 3.90's made for the 3/4 ton Eaton axle. There were a very, very few models that had a 4.11. Been lookin' for over a year and haven't had one single bite.
Where there is a demand there should be a supplier. I can't for the life of me figure out why one of the gear grinders hasn't set up for one that will fit the 3600 AD's. I don't know anyone that has a 3/4 ton that doesn't want to go with a higher gear than the 4.57. Oh, maybe there are a couple but that would be 1 out of 10,000.
Good luck!
Denny Graham
Sandwich, IL



Denny G
Sandwich, IL