Posted by Fred Coldwell on September 30, 2000 at 15:41:26:
In Reply to: Next question and to answer the post below "why?" posted by Brian in Oregon on September 30, 2000 at 14:22:57:
Brian:
WDX/WM-300 rear axles are offset like the M-37 rear axle. Centered WC 3/4 ton rear axles is preferred, as both rear axles shafts are of equal length and strength. Early WC 3/4 ton axles used third members with 8-3/4" ring & pinon, mid- and late war ones used third member with 9-5/8" r&p (stronger).
M-37 third member uses 9-5/8 ring & pinon and 7/16" mounting studs, and will not bolt into a WC 1/2 ton axle without modification, which was built to use third members with 8-3/4" r&p and 3/8" mounting studs.
WC 1/2 ton axle shafts are slightly smaller in diameter than WC 3/4 ton and M-37 axles shafts (from foggy memory, 1-1/16" vs. 1-1/8"), so will not mate up correctly without swapping out the female spline receivers in each side of the third member.
WC 3/4 ton centered rear axle is probably same strength as M-37 but axle shafts may break less often due to equal length axle shafts vs. short and long rear axle shafts on M-37. Also, you'll only need to carry only 1 spare rear axle shaft, not two different lenngth ones, unless you expect a very hard day.
For further information on this topic, I recommend John Zentmyer's excellent 1981 book "Power Train and Interchanges: Military/Civilian Trucks 1941 to 1971 (Dodge)" [TM9-1808C] available from the MVPA or VPW. I re-read it every year and understand more on each reading.