James_Douglas Posted January 5, 2016 Report Posted January 5, 2016 Hi All, I wanted to connect with anyone with a Dodge D34 with an M6 trans. What I want to know is if you know if there is any difference in the internals of the M6 as used in the Dodge D34 versus the Chrysler and Desoto's. Thanks, James Quote
Dodgeb4ya Posted January 5, 2016 Report Posted January 5, 2016 1950 Dodge, DeSoto and Chrysler M-6 transmissions internal gears/ratio's ect are all the same. The side shift covers can be different also the rear E-brake drums because of the U-joint design differences between car lines. 1950 has an early and late M-6 transmission design... Early 1950 models use an external brake band around the E-Brake drum Late 1950 models use the E-brake drum with two internal brake shoes. Extension housing are different because of this change... internal parts are still the same. Several update changes in 1951-53. Quote
James_Douglas Posted January 10, 2016 Author Report Posted January 10, 2016 Hi All, Years ago I know a guy who swapped in a M6 for a bad one. It worked fine, but the guy said the car felt like it was accelerating different and RPM was climbing faster sometimes and could not understand why. That comment stuck in the back of my head. Turns out my little voice was correct. Something was different. I just received an original hand typed two page note from Chrysler Engineering. It explains that when they came out with the Fluid-Torque-Drive that they CHANGED the gear ratios in first and third gear. It is not clear if they just changed the M6 on those cars that came with a V8 or all the Fluid-Torque-Drive cars. The document is very early in 1950 just as the V8 was coming out. So, if one is playing swap games with M6 transmissions, know that there are internal differences. James. Quote
Dodgeb4ya Posted January 11, 2016 Report Posted January 11, 2016 (edited) The Fluid Torque Drive M-6 trans has a completely different input shaft and gear ratio's just like the Hy-Drive Plymouths. A FTD transmission and matching "Torque converter" is a whole different much more complicated ball game than the common FD with the standard M-6. Just looking at one (FTD M-6 ) you can see it's a different transmission externally. So James.....did I help you at all with the info I supplied trying to answer your question... Or did I fail at it? Bob Edited January 11, 2016 by Dodgeb4ya Quote
James_Douglas Posted January 16, 2016 Author Report Posted January 16, 2016 The Fluid Torque Drive M-6 trans has a completely different input shaft and gear ratio's just like the Hy-Drive Plymouths. A FTD transmission and matching "Torque converter" is a whole different much more complicated ball game than the common FD with the standard M-6. Just looking at one (FTD M-6 ) you can see it's a different transmission externally. So James.....did I help you at all with the info I supplied trying to answer your question... Or did I fail at it? Bob Bob, What I was looking for was is there any differences in the "inside". The input shafts were different if you had an M6 or a 3-speed with a fluid coupling and they also used a different input shaft for the torque converter. However, what the document turned up was that they changed the gearing in side the main housing. Common wisdom was that the gearing was all the same save for the change from the plate type to the pin type syncro. I will dig out my scanner at some point and post the tech note. James. Quote
Dodgeb4ya Posted January 17, 2016 Report Posted January 17, 2016 I also have acquired hundreds of chrysler corp. service bulletins on all phases of service repairs. They have helped me on service work on the old Mopars over the years. Quote
countrytravler Posted January 17, 2016 Report Posted January 17, 2016 I would love to see the service bulletins on these trans. Quote
Dodgeb4ya Posted January 17, 2016 Report Posted January 17, 2016 (edited) Some pics Dave... Edited January 17, 2016 by Dodgeb4ya 1 Quote
dpollo Posted January 17, 2016 Report Posted January 17, 2016 To the best of my knowledge, they are the same. Quote
James_Douglas Posted January 17, 2016 Author Report Posted January 17, 2016 Attached is the document that talks about the changes in the main case of the M6. In particular there was a change of 1st and 3rd gear. Since the gears and the like are interchangeable, within respect of the plate vs. pin syncro's, one could change the ratio of 1st and or 3rd gear. I suspect that the guy that some years ago swapped his M6 in a flathead six used one from a "converter" car and just swapped the input shaft. Just as I did when I went to the 3-speed from an M6 in my big Desoto. Best, James. 1 Quote
James_Douglas Posted January 17, 2016 Author Report Posted January 17, 2016 I also have acquired hundreds of chrysler corp. service bulletins on all phases of service repairs. They have helped me on service work on the old Mopars over the years. I have a big pile of them as well from an old service department. The binder is like 6 inches thick! Scanning would take me a solid month! James. 1 Quote
Dodgeb4ya Posted January 17, 2016 Report Posted January 17, 2016 (edited) Absolutely amazing collection James!. With that huge collection of factory service bulletins you should quickly be able to find good answers to all the problems you are having with your cars. Those bulletins have the correct info unlike some info you find online. Read them...study them... soon enough your'e DeSoto issues will be solved....................Hopefully! Edited January 17, 2016 by Dodgeb4ya Quote
countrytravler Posted January 18, 2016 Report Posted January 18, 2016 (edited) I have a big pile of them as well from an old service department. The binder is like 6 inches thick! Scanning would take me a solid month! James. We have the same. Have 3 binders of service bulletins from 1933 to the 50s. About 1000 plus pages. Saw nothing of what you posted. Would be cool to check each other but a big time hog to do that. Are you still working or retired? I'm still working 7-18 with a retail store of old Mopar parts and repair. Also haul cars locally so my time is very little. Would be cool to combined these books. Also have the Dodge binders on the equipment to install on the Dodge cab and chassis 1932 to 1940. Has the specs and pricing on that and a bunch of accessories. Edited January 18, 2016 by countrytravler Quote
James_Douglas Posted January 19, 2016 Author Report Posted January 19, 2016 We have the same. Have 3 binders of service bulletins from 1933 to the 50s. About 1000 plus pages. Saw nothing of what you posted. Would be cool to check each other but a big time hog to do that. Are you still working or retired? I'm still working 7-18 with a retail store of old Mopar parts and repair. Also haul cars locally so my time is very little. Would be cool to combined these books. Also have the Dodge binders on the equipment to install on the Dodge cab and chassis 1932 to 1940. Has the specs and pricing on that and a bunch of accessories. The bulletins I have run from about 1948 to 1957. All Chrysler. I have some Desoto ones from 1946 to 1949 here and there. I may check around and see how much it would cost to have a professional high speed scanner company scan the stuff. Then everyone can use it. I am retired from my Job as a Chief Information Officer. I just cannot put up with Corporate America any more. I do some projects now and then if they are really interesting. I am also restoring some cars for folks as a 1/2 hobby and 1/2 side gig. Mostly for the fun of it. One thing I am on the hunt for is a good set of old mechanical front end alignment tools. Basically, a set of plates, a toe bar, and the hanf on the wheel camber/caster/kingpin gauges. If you run across a good set let me know. James. Quote
Dodgeb4ya Posted January 19, 2016 Report Posted January 19, 2016 You can find good alignment tools on E-bay easily... if you have enough money to buy them and knowledge on how to use them.... The turn tables are huge $$$$. You gotta pay to play. Quote
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