The Stovebolt Site Forums The Parking Lot Big Bolts Tranny replacement for '46 2 ton bigbolt

My sons and I are in the process of a slow restoration of a 1946 2 ton bigbolt with a flatbed dump. We are limited in our budget, but would like to finish this correctly the first time so it will last. We have a farm and vineyard in Maryland; and along with using the truck for various parades, we would like to make use of the dump bed for various tasks along our several driveways and perhaps hauling grapes to the wineries at harvest.
At the risk of offending purists on true restorations, I have expressed that I am interested in making truck look as original as possble, but would very much like to make it as user friendly as possible as well so that we can use it semi-regularly. Responding to that, the gentleman guiding us in our restoration process suggested the possibility of replacing the tranny (w/ PTO) with a newer one that would be synchronized and allow us to use the truck without the struggle of double clutching and grinding gears. I am interested in any thoughts from those with more years of Bigbolt wisdom than I.

I agree to update but if your trans & PTO still work ok use it then pick up what you need as you find it. I've seen enuff newer trans in the older trucks to know it is a common upgrade. I'm willing to bet you will know all you need to about it from this thread-there is an uncanny amount of knowledge here. Study the info you get for any thing you might have to buy twice if you don't upgrade as you restore to help you decide. Steve

If you don't need any more speed (doesn't sound like it) then just a newer model 4 speed would be good.

Look for an SM465 because PTO's will be more available.
Or the older (but newer than yours) SM420, but PTO's are a little harder to find, used is about your only option.

Investigate how the newer transmission will bolt to your bellhousing. I'm thinking the large hole in the bellhousing might need to be enlarged depending on which transmission you use...

Before making a dump bed check with your insurance company. Many flat out won't cover a dump truck, and most charge a higher price if they do.

Grigg

Thanks "Emptyoilcan" and "Grigg" for such quick responses. All info is helpful. We are looking only for minimal highway speed and not sure if the original would get us there. Some of the wineries are a couple of hours by car.
The truck already has the dump hoist so it is what it is and that is part of what attracted us to it. Unloading a pick up truck full of mulch or gravel is exhausting with a shovel. Very interesting comment reqarding the insurance on the dumps. We will definately look into that.

Also, if you are looking to go farther and faster, don't forget that you will also need to pay some attention to the steering and brakes.

If you make it to the Homecoming next month (over here on the Western Shore ) Go here to see details on the Stovebolt Homecoming Weekend , there will be quite a few 'Bolters in attendence who can offer tips -- even Grigg might show up ... Bring that truck!

Regards,
John

Thanks for letting me know of the Homecoming. We will definately try to make it. I also see a "Leonardtown" show. Is that Leonardtown, MD? We took about 6 1/2 tons of Chardonnay grapes to the new "Port of Leonardtown Winery" at our last harvest. They are doing a great job.

As for going farther and faster, we have replaced all of the wheel cylinders and have to look at the master cylinder as well. We have not yet done anything with the steering, but I will put it on the list.
Again thank you for your kind response.
Chip

With a load and the original engine I doubt you can or want to go any faster than it will already go.
It was a new truck once, and built to safely handle the designed load, although not as fast as we are accustomed to today.

So after checking and rebuilding the brakes and adjusting the steering gearbox if necessary that's about all there is to do other than use it.

If you want to go faster you'll need more power and then better or more reliable brakes, it can be a slippery slope of modifications.... before you know it you'll have a diesel engine and who knows what else...

Grigg

What kind of dump is it? Is it a gravel bucket or is it a field truck? If it is a field truck, call it a restored farm truck and take some good pictures of it that just happen to not show the hoist. I have a 53 GMC insured with JC Taylor that has a hoist. They never asked if it had a hoist and I didn't volunteer any information. If its a gravel bucket, the only way that I know to insure it is commercial insurance which costs at least $1500 a year.

this is how i did my 46 gmc 1.5 ton
trim cross member
by a altered bellhouseing got mine from jim carter this is so you can keep brake clutch pedels
i had to shorten driveline 1 in
i have pictures of crossmember i dont know how post pics but i can email them
sure makes shifting nice
ps i own a winery in calif punch in graton ridge.com

good luck art444

Art, you forgot to mention what model transmission you used...

dang not sure but i think it came out 53 chev pu i dont know numbers of tranies
i do have tranie oout of 59 gmc 2 ton looks the same
art

Should be an SM420 4 speed.

I don't want to be judgmental. But, I have a 46 two-ton flat bed dump and I find it no problem at all to change gears. It is only a little difficult at first until you learn the "personality" of the transmission and the sound of the engine so that you can synchronize the transmission by ear. Before spending the money, time and effort to change the transmission I would strongly advise driving it a while and discovering the pleasure in working the clutch and the gears so as to slide the gears into place withour grinding.

If for some reason the old one is bad I'd upgrade to the newer, it's not that much trouble or money.

I also agree that learning to drive what you have is a superb idea, and it really isn't all that bad either.

But I might not be one to take advice from... I removed the synchronized transmission in my truck and swapped for a completely non synchronized one...

Grigg

If you have the sliding gear transmission now, a later model transmission you will have to use a later clutch housing. The bolt pattern on the sliding gear 4 speed and the SM420 and SM465 is different. A later clutch housing will bolt to your engine, but there is something else that needs to be modified. Possibly the starter or clutch linkage. If there is nothing wrong with the sliding gear transmission, I'm not sure its worth replacing it with a later transmission. I agree that learning what to drive what you have is not a bad idea.

what part of the eastern shore are you on? Quite a few winerys popping up. A couple below the line in Virginia and a few above Salisbury. Have a spare SM420 if you wanted to measure and check bolt pattern. keeping it around as don't know what I'll break next.Located Pocomoke.Also check the difference in pedal mounting bell housing etc. compare to yours.

Seems to me a lot less work and more fun to learn how to shift the old 4 speed. Once you get the hang of it you hardly need to use the clutch some of the time.
I'd keep it original or if you want it modern then update everything from the engine back.