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I am getting ready to rebuild the rear brakes on my M38. She's a bit of a mutt; the rear axle is a dana 23-2 from a GPW with M38A1 style brakes. This much I am sure of. I would like to put the original style brakes (to the 23-2) back on. I have a couple of dana 41s from late 40s CJ2as. I would like to use the backing plates off a civilian dana 41 to rebuild the dana 23-2 as it appears they would bolt right up. My question is two fold.

Are there any differences, however small, in backing plates used on the dana 23-2, 41, and 44 (either civilian or military) from 1941-1953?

Also, are the 53' and later M38A1 style brakes superior to the earlier M38/CJ3a style brakes? (stopping power?, adjustability?)

Thanks in advance for any advice. I just want to be sure before I go and pull hubs, etc.

Brakes on the Willys jeeps were adequate in the beginning and had only one direction to go and that was up towards better. If you are running the 23-2 on a M38A1 then stay with the A1 brakes.

The MB/GPW/M38 all use 1 3/4" wide fixed anchor shoes with 9" drums and the same 4 eccentric adjustment setup. The A1 uses a floating 1 3/4" shoe, 9" drum and a 2 eccentric adjusting setup. The M38 back plates and drums have a better sealing fit that keeps out dirt and moisture to a greater degree.


Are you sure the 23-2 came from a GPW? The MB/GPW 23-2 had 4:88-1 gears and the early CJ2A 23-2 was 5:38-1. M38 and M38A1 25's, 41's and 44's used 5:38-1 gears.

Wes:

Thanks as always.........

The rear axle in question has script F markings on the axle shaft flanges that bolt to the hub. This fact combined with the castings on the housing webs (I have them written down at home, GPA 4025...?) led me to believe it was a GPW axle. Regardless, axle ratios don't help me out as i have 4.55 gears (41/9).

Just to clarify, there should be no clearance issues when you mix early or late style brakes (all 1-3/4 shoe, 9" drum) with 53 and prior dana 23-2s, 41s, or 44s?

Right now I can't think of any so long as you use all the parts Backing plates, everything mounted on the backing plates and drums that belong together.

Maybe I misunderstood which axle you are using on your A1. I understood you were using the 23-2 on your A1 and the 23-2 already had A1 back plates and brakes?

I mention the gear ratios because the front and rear axles must match ratios.

The M38A1 brakes are superior to all preceding Willys brakes.

MB/GPW back plates were Willys # A450 which was superseded by Bendix # 47054

M38 back plates were Willys #800747 which was superseded by Willys # 641917

M38A1 Back plates were Willys # 807375

CJ2A and CJ3A backing plates were Willys # 641917.