Stumped

[car crazy]

Does anyone have any idea what this canister is that is next to the transmission in my 1941 Plymouth Special DeLuxe, 3 speed manual transmission? Just a little stumped!  

[Steve_Mack_CT]

No but how about a pic or two of topsides?  First antique, any car for me was a 41 Ply 2 door P11.  I learned a ton, but do not recall a cannister like that.  Understand that was over 40 years ago though...

[JayG]

It looks like it has the Fluid Drive assist that was offered starting in 39

[The 55er]

Plymouths never had Fluid Drive like the Chryslers, DeSotos & Dodges had back in the day. It might be a canister for the optional vacuum-assisted Powermatic Shifting Mechanism that was first offered on 1941 Plymouths. It allowed Plymouths to be driven most of the time in second & high gear. 

Edited August 22, 2022 by The 55er
misspelled a word (see edit history)

[Scooter Guy]

If this article is accurate, it sounds like it is the "semi automatic" transmission mentioned here:

 

https://www.allpar.com/threads/the-chrysler-plymouth-dodge-desoto-fluid-drive.229898/

 

Scroll about 1/3 of the way down the page. 

 

 

[61polara]

I believe that it is the optional vacuum shift (like Chevrolet) that Chrysler offered in 1941.  I've never seen one, but it's in the parts manual.

[John_S_in_Penna]

1 hour ago, The 55er said:

It might be a canister for the optional vacuum-assisted Powermatic Shifting Mechanism that was first offered on 1941 Plymouths. It allowed Plymouths to be driven most of the time in second & high gear. 

Mr. 55er, I respect your Chrysler product knowledge

in this and many other topics.  It's clear you're an

experienced Mopar owner or researcher.

[car crazy]

Thanks to everyone for all the info.

[Steve_Mack_CT]

I never knew this was available in 41.  I later had a 47 Chevy with that arrangement and thought they were first with it.

[61polara]

12 hours ago, Steve_Mack_CT said:

I never knew this was available in 41.  I later had a 47 Chevy with that arrangement and thought they were first with it.

Chevrolet introduced the vacuum shift in 1938 as an option and made it standard in 1940-1948. Chrysler only offered it in 1941 on the Dodge and Plymouth lines which did not have the semi-automatic transmission available.  With the Chevrolet vacuum shift, the distance the gear shift leaver moved was greatly reduced and the vacuum assist made the shifting light enough that one finger could move the gear shift leaver.  I assume that the Chrysler unit also shortened the shift leaver throw.  This unit is a vacuum assist unit that only assists in the effort to move the gear shift leaver.

 

16 hours ago, The 55er said:

It allowed Plymouths to be driven most of the time in second & high gear. 

You are thinking of the action of the fluid coupling (Fluid Drive) that was available on Dodge, DeSoto and Chrysler that would allow you to stay in third gear (or second), come to a stop without using the clutch and then pull off in the same gear.  The fluid coupling was never offered on Plymouth.  You still needed to manually shift the gears.  No shifting was done by the Fluid Drive unit without the semi-automatic transmission.  The prewar Fluid Drive semi-automatic transmissions were vacuum shifted, but that unit is on the top side of the transmission and is different from this unit.

[The 55er]

This is the information I found on the 1941 Plymouth Powermatic Shifting mechanism, maybe I misunderstood something. The third picture is from the actual magazine ad. 

Edited August 23, 2022 by The 55er (see edit history)

[61polara]

2 hours ago, The 55er said:

This is the information I found on the 1941 Plymouth Powermatic Shifting mechanism, maybe I misunderstood something. The third picture is from the actual magazine ad. 

I see where the confusion is coming from.  The wording of the article is confusing and is actually discussing two different things.  1) Plymouth offered the vacuum assisted gear shift in 1941 as a $6.50 option. 2) The author of the article should have started a new paragraph for the next sentence, because he is now stating that for 1941, all Plymouth cars had a lower second gear ratio and a lower rear end ratio, unrelated to the "Powermatic" vacuum assisted gear shift.  The lower second gear and rear end gear would permit the driver to start in second gear more often but limited highway speed.  The Powermatic vacuum assist gear shift did nothing automatic but only gave a light touch to moving the gearshift leaver when shifting.  You still needed to manually shift between gears.

 

Hope this clears up things.