james weber

What year transmissions and rear ends will bolt into a L37 4 door touring sedan? Thank you.

47 Convertible

1. You need a reprint 16th Edition of Hollanders Interchange Manual available for $45. https://hollanderinterchange.net/cat...x.php?cPath=21 It is the top one on the first page.

2. Your 1937 Olds uses what Hollander refers to as a #253 transmission. It was apparently used on all 6 and 8 cylinder Oldsmobiles in 1937. All 1937 Pontiacs also used the 253 trans. According to Hollander the #259 transmission will interchange and the 259 was used on 1938 Oldsmobiles and all 38 Pontiacs.

3. Your rear end carrier assembly is what Hollander calls a #320. It is for 37 and 38 Oldsmobiles, both 6 and 8 cyl. 37 and 38 Pontiacs also use it. It does not appear that earlier and later Oldsmobiles used it.

The Hollander has a lot of other informational jewels in its pages including both mechanical and sheetmetal interchanges. I don't get a thing out of recommending it but it is the best $45 you will spend on car stuff. It covers all makes and models from the 20s to 1948.

Jerry

47 Convertible

More information on L37 trans and rear end interchange:
It appears your rear end will interchange, with some bearing size changes with 39-48 Olds #360 carrier assembly. The Hollander goes into some detail on how this can be done but it is too much for me to transcribe here. Again, get that 16th Edition Hollander.
Jerry

james weber

Thank you. I have that Hollander book. I was thinking that maybe something newer would work. Would the newer books overlap enough to work? Thank you.

47 Convertible

I haven't a clue on that. As you know the older Hollander ends at 1948 and Old's use of flathead engines ends at 1950 (?). I only have the older Hollander. It doesn't seem like there would be much benefit in going to the next newer Hollanders but You could contact the Hollander people and ask them how much overlap there is.

If you are upgrading but want to leave it looking stock why not go for the whole power train from a 46-48. You get a very similar flathead 8, 3 spd and rear end. Fewer worries about interchange. At worst you might have to go to the newer motor and transmission mounts and do a little work on clutch linkage but I would think those things would be quite similar to your current L37 power train. Sale of that would get you some of the money back from purchase of the newer power train. Just my nickel's worth.
Jerry

citcapp

James,

What kind of results are you looking? Do you have the original running gear or is it missing and you want to upgrade and basically keep everything stock looking. Or do you want a more modern driver?

james weber

I would like a fully synchronized 3 speed plus any thing but the 4:33 gears I have now. I would like to go 65 mph with out blowing it up!

47 Convertible

I saw a reference to an Oldsmobile AST (automatic safety transmission) that was different than the regular 3 speed. It apparently was offered in the late 30s before the hydramatic came out.

The AST acted kind of like Mopar's Fluid Drive and apparently had a numerically lower rear end ratio that was made possible by virtue of the fact the AST low range had two gears and the high range had two gears. You might want to do some research along that line or maybe you are way ahead of me on that.

Other than that suggestion, I'm out of ideas.

citcapp

I would suggest that you check around in your area to find some one with a 46-48 Olds and check out the drive train to see if you could swap out engine to rear end complete. You might be able to find a complete setup as these are quite often turned into hot rods and they sell the whole works. Other the moving up to a complete Olds V8, modern transmission and rear end I am out of ideas