I have a spare Sm420 that I would like to play with, learn some and maybe rebuilt if required/desired. Has a brake which I will remove and replace with a back plate suitable for my stock drive shaft. 283 engine. Can someone ID this transmission? What back plate am I looking for? What am I asking/looking for? Are the input and output shaft splines correct or do I need to fuss with shafts as well, which might be the deal closer. Thanks for any help to get me started.
~ HB 1966 Chevrolet K-10 | Ghost: formerly Flappy Fenders | In the Stovebolt Gallery 1962 Chevrolet C10 1962 Suburban
Your trans was casted on April 6th 1962 and was setup for big truck with handbrake/drum mounted on the transmission. You only need to remove the rear bearing cover and replace it with the standard duty cover from 1948 on up to 1966 like this one attached part number 591701, Type in that part number in ebay and one is for sale now.
Input and output shafts are compatible and correct, in actuality, once the drum is removed it (your existing bearing cover)doesn't even need to be removed, it will accept the standard driveshaft yoke but it would clean it up nicely otherwise.
Steve
Last edited by sstock; 03/08/20197:53 PM.
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
No the parking brake drum is removed only, exposing the rear bearing cover
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
Is there any reason to remove the parking brake drum system? I have done it, but after fighting the cable system on my 52, I am considering putting one on so as to not have to deal with the misery of the cables
No, actually it is a better parking brake system IMHO, designed for heavy vehicles fully laden.
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
I have been told that there is damage to the brake bracket in my pictured transmission. I believe in pix 3, on the left side, the arm (?) that holds something against the drum is busted. I have been told this renders the brake/back plate useless and on no value to anyone.
~ HB 1966 Chevrolet K-10 | Ghost: formerly Flappy Fenders | In the Stovebolt Gallery 1962 Chevrolet C10 1962 Suburban
Yes, I see that now, sorry for not catching that. Still if you wanted to save a few bucks and do a little work, you could cut the existing bracket in these locations and use it after replacing the rear seal of course. Steve
Last edited by sstock; 03/09/20192:25 PM.
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
I have been told that there is damage to the brake bracket in my pictured transmission. I believe in pix 3, on the left side, the arm (?) that holds something against the drum is busted. I have been told this renders the brake/back plate useless and on no value to anyone.
Yes, the band brake support shank is broken off of your Retainer Plate. The only thing that plate is good for now is for a 1/2 ton truck that doesn't use a propeller shaft parking brake system...they uses cables to the rear axle drums like a car.
Mike B
Mike Boteler
1956 Chevy 3100 Resto Rod 1952 Willys M38 Army Jeep 1983 Jeep CJ7 Laredo 1984 Jeep CJ7 +++++ Silver Spring, MD
