Does anybody know if the pinion and ring gear and carrier from a 40 pick can be installed in a 37 rear (both 1/2 ton)?
At first gland the internal sizing looks compatible. The 40 has a thicker shaft and bigger caps for the internal axle bearing, but the bearing appear to be the same size. I did not get the 37 pinion out yet.
I was going to switch rears to allow a 3.55 gear. I have the u joint covered. The 40 rear tube is 1.5 inches longer that the 37. I either have to 1) cut the tube, 2) change the guts between the two (if possible), or 3) mount the rear axle 1.5 inches back of center on the leaf spring (which is more centered than original in the fender).
Any direction would be helpful.
Mike J
Last edited by Mike J 37 GMC; 08/12/2013 12:28 PM.
