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See lots about 4.89 gears for the M-37 regards a few more MPH etc .... where would one start regards purchasing a set of gears of a complete package to swap out? Thank you.

Hi Mk,

Vintage Power Wagons (VPW) had the gears made and started selling them in late summer 2014, I believe. If you want someone to install them in your diffs there are a few folks still around who can do that. I believe Charles could help you out, and Adirondack Dodge could too. I don't know if VPW installs the gears or not, but a quick phone call would answer that one.

later,
bob

Vintage Power Wagons is the only source for 4.89 gear set purchase.

We have all the other parts for complete rebuilding in stock, we also offer complete rebuild service and set up if you need it.

Thank you for the information, I'll look into it.

A nicely made set of American gears at VPW ... have way more time than money and am fairly handy with a wrench, how difficult it if it switch out the ring and pinion gears? Looks like it's just a matter of pulling the axles, pumpkin and swapping out the components if all the other goodies are in good order. Am I being a bit naive here. Have never done a differential before, but have my manuals. Anyone out there been in a similar situation.

mkoloc wrote:A nicely made set of American gears at VPW ... have way more time than money and am fairly handy with a wrench, how difficult it if it switch out the ring and pinion gears? Looks like it's just a matter of pulling the axles, pumpkin and swapping out the components if all the other goodies are in good order. Am I being a bit naive here. Have never done a differential before, but have my manuals. Anyone out there been in a similar situation.

Having done many differential set ups myself; IMHO, yes you are certainly being naive about it. It takes special tooling to do the job right, some of which is precision tooling. I don't know what you may be thinking; but this job is far from just unbolting the old and bolting in the new. I've seen very few differentials that didn't need a full rebuild, (especially a spider gear kit) along with the gear set installation. At $500 + for a set of gears; it isn't something you need to short cut on other needed repairs to the unit, or the proper workmanship required for precise set up. We have had several sent to us here that had obviously failed because set up was not done correctly in combination with reusing some parts that should have been replaced. The truth is this is the highest cost gear box on an M37 to rebuild. That really makes the job high risk if #1, you don't have the correct tooling, or #2, you do not have the experience and expertise to tackle this project. Something else you will learn quickly is this; the info provided in the military manual is basically for a "can't do any better field type repair." It does not even cover the set up procedure as far as obtaining a correct tooth contact pattern and numerous other issues you need to know and fully understand. If you plan to tackle this job using a military manual, without access to all precision tooling that is required, etc.; you will without a doubt come up short in the end.

Appreciate your frank response Charles, after all I did ask and you seem to be in that business and as someone who owns a successful watch and clock restoration business I certainly understand precision especially the type of precision needed to restore century old watches (micro-machining) ... If I get to the point of switching out one of my M-37's, you may be hearing from me in the future or because I enjoy a challenge I may try to muddle thru it on my own using one of those old Army manuals. I'm kinda partial to Army manuals as I retired in 2011 after 33 years of service.

There is no magic to setting up a differential and plenty of good manuals on the procedures. It is not, however, a just bolt it in and done type job. There are many steps to a correct job and often, you have to do it several times to get it correct. Assemble, measure, dismantle, reshim, assemble, measure, repeat.
Not something easy to do without someone to mentor you through the first time or two.