I posted this in the trans/enging forum but thought someone here might have some information on it. Can someone identify this transmission. I got it with some 3600 truck parts and I've never seen one with a secondary output shaft like this one. Here's some numbers I got off it if it helps. 591568 Gm4 D200 Conv5 591885
looks like a Gm Muncie sm420 with a pto. should be synchronized from 2nd through 4th made from 47 to 67 if that helps
Transmission It would be great if you could post some more photos of the tranny.It would be easyer to tell you what brand and model it is. Thanks Martinius.
Tranny Identification Update HOtrod53: Thanksfor the info. I also found a site that has some of the numbers so now I know it's a SM420 4 speed Muncie trans that has a PTO. Now if I can find out what a PTo was used for on a 3/4 ton truck I'll have the mystery solved. Blueflame: I only had the one picture that my son sent me since the parts are at his place. I'll post some more if I can get him to use that smartass phone Thanks Guys for the help.
that tranny was used on everything from a 1/2 ton up to a 2 ton truck most likely was on a dump truck
SM 420. 1/2 & 3/4 ton only. Since it has the enclosed U-joint provision on the rear... would only have been used on the 1/2 & 3/4 ton trucks . The 1 ton & up trucks had an open U-joint provision.
More likely someone with a busted SM420 tranny in their 3600 replaced it with a SM420 w/ PTO from a bigger truck.
Can't be from a bigger truck Bill as it has the rear provision for an enclosed U-Joint & those were only used on the 1/2 & 3/4 ton trucks
Serial Numbers Your casting # was the next generation 4-speed, first used in 1948 thru late 1951. To better identify it, post the Serial Numbers. Located on the .... Rear, Right hand side, of the Case.
