Question abou the 1947 4 speed tranny

[Zach B]

About 3 years ago my dad and great uncle gave me this 47 chevy short bed that they had owned since before a was born. They had not touched the truck in all that time with the exeption of a seat. All the truck had was the frame, axles, transmission, the cab, and everything forward on the body. I'm wanting to go original with it but I have recently learned I may have a snag. I have yet to open the housing and see what kind of shape the gears are in but I'm worried about them being broken. If they are I don't know where I would go for replacement gears because of the fully unsyncronized part of it. Do any of you know where I would find a kit for it and still have a fully unsyncronized transmission if it does turn out to need repairs?
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[mechanixman]

You shouldn't need to worry about the trans being that busted. Only first and reverse are unsynchronized. There are a few places to get kits, but as Orrie and Ogre have suggested, go buy a trans from one of the other board members. I found an extra one on craigslist for $10.

[mr48chev]

Rebuild kits with new bearings and small parts are readily available from the normal vintage truck goodie vendors. As Mechanicsman said, decent used transmissions especially compound four speeds are quite inexpensive most of the time and pretty easy to find.

I'd get the manual out and study it for a while before taking the trans apart. as far as transmissions go they are pretty simple and you don't need a bunch of special tools or serious skills to work on them. I would suggest a bare clean work bench or table to work on so you can keep track of all of the small pieces with maybe some containers to put small parts in and a sharpie to label them.

I'm thinking but not positive that the 47 Fourspeed is the early version of the Muncie SM420 transmission. You would have to do a bit more research there to make sure.
There is parts list on this site.
http://www.drivetrain.com/parts_cata...rhaul_kit.html

[_Ogre]

those transmissions are bullet proof, unless it has been run dry or terribly abused i wouldn't worry about it.
they will run/pull/shift fine with chipped teeth and bad syncros
unless your towing with it, you will never use first gear

[Zach B]

Thanks for the info on it. My transmission is diferent from all years latter I know. To engage reverse I have to pull a lever and shift between 1st and 2nd then pull down. I have never Sean this in any transmission made after that. From what I have found it's the 1940-47 transmission that had that.
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[dwcsr]

You'll be surprised what's still available for those. Figure out what you need and I'm sure someone here can help you find it. Or over on Stovebolt.com

[Zach B]

I knew a lot of things were still available and probably more available now than 3 years ago it's just a matter of going to the right corners to find it.
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[Zach B]

i forgot to take picks but this is one of those incidences the transmission is on the edge of my trust because of some chipped gears. probably fine but better safe than sorry will take it to a guy who is familiar with these.

[mknittle]

Here for one.

http://hermtheoverdriveguy.com/?page_id=1478

[Zach B]

That's for an sm-420. Mine is before sm-420.
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[_Ogre]

Originally Posted by _Ogre

those transmissions are bullet proof, unless it has been run dry or terribly abused i wouldn't worry about it.
they will run/pull/shift fine with chipped teeth and bad syncros
unless your towing with it, you will never use first gear

i'm going with my original post.
i don't think you have a problem.
post some pictures of how bad the gears are.

[Zach B]

I still have not taken pics but I found chips in all gears the one toward the back of the housing being my main concern. About 1/4 of every other tooth is gone. Also that gear that you can see in the back of the tranny without opening it has half a tooth missing. It's bad enough that you can tell whoever drove it in the past did not know how to avoid grinding gears.
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[tttuba]

I have the same 47 gmc with the same transmission with the reverse lockout....This guy has a rebuild kit and may be able to get you what you need or give you info.
http://www.nwtparts.com/policies.html