| |
Click on image for the lowdown. 
====
| | | Forums66 Topics128,132 Posts1,056,383 Members48,441 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Sep 2007 Posts: 393 'Bolter | | 'Bolter Joined: Sep 2007 Posts: 393 | I have come across an SM420 transmission with the driveshaft braking system attached. I realize that these systems were used in the bigger bolts. Is the parking/e brake system able to be removed? Would I be able to use this transmission in a 1/2 ton (if the brake is able to be removed?
It's a small world, but I wouldn't want to paint it.
| | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Yes, the parking brake parts can be removed.
Yes, but you might need a different rear cover on the transmission in order to connect to an enclosed driveshaft, depending on the year of the SM420 and year of the 1/2 ton truck. | | | | | Joined: Sep 2007 Posts: 393 'Bolter | | 'Bolter Joined: Sep 2007 Posts: 393 | Thanks, Tim. From what I can gather, it's a 1948-1957 SM 420.(Casting number 591953 Code above casting number is D 215) I have a torque tube rear end which I plan to transplant into my '47 with the SM 420 if I can figure out what I need for the rear side of the transmission. (I can't find any numbers on the rear end but it's 6 lug and has Bendix brakes..)
It's a small world, but I wouldn't want to paint it.
| | | | | Joined: Apr 2012 Posts: 124 Shop Shark | | Shop Shark Joined: Apr 2012 Posts: 124 | If you can get the floor section from the bigger truck it will probably fit right in your half ton. I swapped it all out in my '59 and use the brake just like it was in the bigger truck. It probably isn't the best parking brake though.
Gene
1959 Apache
| | | | | Joined: Mar 2004 Posts: 6,214 'Bolter | | 'Bolter Joined: Mar 2004 Posts: 6,214 | Gene, If I understand Rusty correctly he need to remove the transmission parking brake on the SM-420 so he can convert it to a torque tube type rear...you can't have both! The transmission brake is a great brake for your pickup, if it will hold a 20,000 pound big truck it should have no problem holding a 3,500 pound pickup! Mike B  | | | | | Joined: Apr 2012 Posts: 124 Shop Shark | | Shop Shark Joined: Apr 2012 Posts: 124 | Gene, If I understand Rusty correctly he need to remove the transmission parking brake on the SM-420 so he can convert it to a torque tube type rear...you can't have both! The transmission brake is a great brake for your pickup, if it will hold a 20,000 pound big truck it should have no problem holding a 3,500 pound pickup! Mike B I see what you mean. I didn't think about the closed in drive line. I was just thinking about the extra hole in the floor for the parking brake. I should have just kept quiet as I know nothing about torque tube set-ups. Never mind.
Gene
1959 Apache
| | |
|
|
| |
