The Stovebolt Site Forums The Side Lot Old Dominion Stovebolt Society (MD, VA, West VA, DC, DE and PA) 47 Dually - Started......

Brethren, knowing my grandfather's truck would take a fair amount of time and energy to rebuild I have been searching for an interim stovebolt to keep me interested. I searched and found a 1947 1-ton dually EXACTLY the same as my grandfathers, or so I thought. The owner sold it to me "as-is" and said it doesn't run, "froze up". Northern alliance brethren, 53-green 1-ton coached me through obtaining spark a week or two ago. It sure wasn't froze up. Yesterday, Jim showed up in the 53, tore down my carb, remounted it, and we got it to fire. I still need to hook up a fuel tank to get it to run continuously, but it fires strong and runs OK with gas poured down the carb !!! So last night, John showed up, the chef from the Feb. dismantling meeting. We pull out the transmission. And here is where I diverge from a standard 1-ton. This enormous transmission not like my grandfathers SM-420 is installed. It has a 216 with a different bellhousing than mine. This transmission also has a different thickness shifter handle, and an offset handbrake. My sm-420 handbrake just goes straight up. Could this be a transmission from a 2-ton? I welcome comments. Is it a 420? Pictures to follow, when I remember to bring a camera to the shop. Best - Joe

Joe -- Does it have a lock out switch for reverse on the shifter handle? You probably have the non-synchro tranny that was put in the '47's (carried over from the Art Deco's). SM-420's didn't go into the ADs until '48.

Congrats on the new truck
John

I sickness continues to infect. I was once reminded, "just 4 bolts away from..." Let us know when we should come up for the tune up party.

And look at you now -- getting all kinds of kudos and thumbs up larking about in that magnificent machine of yours (sorry -- been watching Brit TV again ...). If I may say so myself, I think you've done rather well by that bit of advice.

You're very welcome, Hamilton. Very welcome indeed. If Uncle Joe does half as well as you, he will have rather a respectable lorry on his hands.

Not sure whether to take those comments as a bit of praise or a I told you so? Either way I have my infection under control for now. I won't say it too loudly, but the advice was good and appreciated under the circumstances. Hopefully no one is reading. Joe, on the other hand, needs therapy.

You guys are funny!

More than one person has told me I need therapy. My reply is "this IS my therapy".

Having said that, Joe still may need therapy.

John - the tranny we pulled in the winter has the lock-out lever to get into reverse. This transmission has no lockout lever and has a bigger diameter shift rod. I HAVE to get you guys some pictures and maybe find some numbers.

Could be a Clark 5 speed, as they came with the GM bolt pattern sometimes... If so it could be overdrive, look for something like 205VO on the tag, the "O" would indicate Overdrive if it has it.

Thanks Grigg, I cleaned it off yesterday and found these numbers:

On a very rusted tag between two flathead screws "1308"

On another rusty tag "CON1/5" (numbers hardly legible)

On another rusty tag "1278"

Stamped GM3 591568 (Top of transmission)

Stamped 3 GM 591665 (side of transmission)

This transmission does have what looks to be a removable sideplate for a power take-off. What is the shift pattern on a 5-speed? I can try running through the gears to confirm?

I'll look to download and send photos when I get near my computer. I'm working off handheld

Thanks gents

A little googling shows you have a plain old GM SM420, the common 4 speed that your truck should have, or no surprise that it does have.
https://www.novak-adapt.com/knowledge/sm420.htm
They say 591665 indicates a 1947-1953 model

Thanks Grigg. What throws me is that my other (grandfather's) truck has a much smaller transmission with a reverse lockout lever to get you down and over to the left for reverse.

That truck, also a 47, built in NY, has a transmission with a code: 5 GM 690474 and top markings 590511. This transmission is much smaller/lighter and has a different bellhousing bolt pattern than the 420 you reference above. So much to learn. I will try and google it to see what's up. I do know that my grandfather's truck is an early 47. Maybe the other truck is a later 47.

Either way - is there a way to add a transmission brake to my SM-420 or should I hunt one down that has it already? Those 1-ton cables are a bear to find off the z-bar linkage arrangement though I like the look.

So your Grandfather's truck has the older non synchronized with reverse lockout lever on shifter; sort of left over transmission from the previous model.
The new truck has the SM420, which is very common in AD trucks, could be a little later 47 model or could have been swapped in at any point in the past 65 or so years.

To add the transmission mounted parking brake to an SM420 that didn't have one your best bet is to find a transmission that does have it and swap parts or whole transmission. I believe the tail housing is different as well as you'd need a lot of the miscellaneous pieces and parts. A good used SM420 with brake should cost less than $150, likely around $75 to free if in the right place right time.

If you do keep the wheel mounted parking brakes my understanding is the folks at Inline Tube have the cables already or can custom make whatever you'd need. I see they list 3/4 ton and I think they'd be real close if not perfect, or may need them to adjust overall length.
They also offer them in Stainless, and not much more expensive either.
http://inlinetube.com/Brake%20Cables/brake%20cable%20listings/bcables7.htm

Grigg

Joe, I have a SM420 that I pulled out of my 41. It has the mounting bracket for the brake, but I don't have any of the other hardware for the brake. You're welcome to it if it helps you.

I also have a 5 speed that came out of a 59 2 ton truck, 2 spd. axle. That will probably fit, but I'm checking to see if it has the brake on it.

Thanks Victor - I may take you up on that. Eventually I am going to have to find a bellhousing as well. The crashbox on the "old" 47 has a different bolt pattern than the SM-420 on the newer truck. I will need one that fits a 235 or 261 motor when I uncover one.....