Transmission

barriefield-brian · #1 13-10-11, 02:36

I have an old tranny here that I have no idea what its out of or how old. I would rather see someone use it than send it to the scrap. Marking on top is GM 691568 and on the side is 00N5 8 L181 591907. Has a long shifter making me think its from a truck. If you can use it give me a shout, Im in kingston, Ontario. Cheers Brian

Bob Carriere · #2 13-10-11, 03:30

Late 58/59 GM 4 speed...... rear bracket looks like it could hold a emergency drum brake arrangement..... looks similar to what I had attached to a 261 1959 5 ton fuel delivery truck that donated my engine...

someone will search the numbers and get it right on......

Note..... Although mine was a nice fully synchro tranny it could not be installed in a 15 cwt Chev as the overall length would not leave enough room for the short driveshaft to the transfer case....

Grant..... what do these numbers say...?

Bob

Grant Bowker · #3 13-10-11, 12:13

My first guess is a SM420 from 1951 based on the web.
Casting # 591907 is linked to several sources to the SM420. One source lists the same casting number for both 3 and 4 speed transmissions which seems unlikely but I guess anything is possible.
L181 looks like a date code. December 18 for a year ending in 1 (1951, 1961 etc. and based on a Stovebolt post more likely 1951). The same Stovebolt post has a link to a brochure on rebuilding the transmission.
http://www.stovebolt.com/ubbthreads/...51932&page=all

Phil Waterman · #4 13-10-11, 18:38

I have a pair of transmissions that look the same which came with the 235 and 261 engines I bought a couple of years back.

But take a look at the 2nd picture is the pilot shaft that fits into the bearing in the flywheel missing hard to tell in the picture.

Cheers Phil

barriefield-brian · #5 27-10-11, 03:03

Safe to say no-one can use this so it can hit the scrap heap? Cheers Brian