ww2dodge.com Forum

I am chasing a synchro or semi-synchro gearbox to suit a flat six in a WC12.
I think the M37 box fits but there must be numerous civilian boxes up to 1960 that would do the job.

Restoring the truck to do a long international trip.

Lang
Brisbane

the only one that bolts in is the M37 box. the other dodge trucks that went synchro in the 50s used a different bolt pattern.

What Kaegi said is true. I just went through all of this on my 55 civilian flat fender.

Look for a M37 B1 tranny. It is the last M37 tranny and is said to be the best of breed. It is synchro only in 3rd and 4th gears. It has the same bolt pattern with the early (pre 55) civilian flat fender trucks as well as the WC's. Not sure when the M37 B1 came out? The civilian NP420 came out in late 55/early 56 and has a different bolt pattern. I sourced a B1 tranny and it bolted right up to my bell housing. I did have to get a late civilian tranny cover, passenger floor board, and e-brake bracket, but everything bolted right up and looks stock. Not sure what you would have to do to the floors on your WC12?

Another fact for you to consider is the civilian np420 guts will interchange with the B1 np420 (same gears, bearings, races, seals, etc.). The cases are the only thing that's different. Furthermore, not sure which one would be better for your application, the civilian np420 shift tower will interchange with the B1 np420 shift tower giving you a couple of options on shift tower location.

I rebuilt mine and I love it. Much more fun/less stressful than the crashbox.

Just to be clear, I started with the original 230 motor and drive train.

Good luck!
Clark

Thanks for that. I am on the track of an M37 box at the moment. Probably only about half a dozen M37 in Australia so not common.

Lang

Got an M37 box with power takeoff today. Hope to open it for a look in the next few days.

Lang

well that was quick. if you need parts they are not hard to find. I have found the synchros are usually within spec. but they are out there if needed

Will let you know the result of inspection.

Lang