fluid drive transmission

[Guest Brady]

I have a 49 dodge wayfarer, with the fluid drive transmission. It hasn't been driven since the late '70s. The torque converter has red fluid filled about 1/2 way to full. It looks like modern transmission fluid. I have read 10w oil should be in the transmission, filled to just below the filler hole. What should the torque converter have in it and how much?

thanks

Brady

[Guest DeSoto Frank]

Hi Brady,

Couple of quick tips regarding your Wayfarer...

1) Find a shop manual as soon as you can, reprints are available from Roberts MOtor PARts, among others.

2) Fluid Drive, and it's Chrysler / De Soto / Dodge variations is NOT in anyway an "automatic transmission", as has been used by auto makers since 1955. In the case of your '49 Dodge, it consists of a "fluid coupling" (not a true "torque converter"), regular single-disc clutch & pressure plate, and a three-speed manual gearbox, with column shift.

3) Fluid Coupling holds about 3 pints of oil, preferably ISO 32 "tractor hydraulic fluid", or in a pinch SAE 10 no-detergent motor oil. DO NOT USE ATF - IT CAN WRECK THE SEALS !

There is an access cover in the floor-pan on the upper right side of the tranny hump; once that cover is removed, there is a cover plug in the bell housing. Once that plug is out, you should be looking at the fluid coupling. Bump the starter or have a helper turn the engine over by hand, until the filler plug of the fluid coupling lines-up with the access holes. Wipe / blow-away any dirt from around the plug.

Remove the plug with a MAGNETIC socket (use a six-point socket, to lessen chances of rounding the corners on the plug). If you drop the plug inside the bell-housing, you will have quite a bit of work to remove the lower casing to retrieve it.

The fluid level should come to the filler plug or high-enough that you can see it on a screwdriver inserted through the hole.

4) Transmission uses SAE 90 gear lube, about 3 pints. Lube should be up to the level of the upper plug on the passenger-side of the gear case.

Get the factory shop manual or at least a MoToR's Manual covering 1940-1954, and read-up on your Dodge.

A very good on-line resource is the '46-'48 Dodge & Plymouth site:

"www.P15-D24.com" , those guys eat, sleep, and breathe flathead MoPar.

Can't stress enough that the Fluid Drive tranny system in your Wayfarer is NOT related to automatic tranmissions; many well-meaning gearheads who are not old enough to know differently may lead you down a wrong-path with well-intended advice.

Good luck with your Dodge !

[Guest elmo39]

frank i,m not trying to belittle what you said , i have owned chrysler product cars from approx 1970, although i have never had a fluid drive , but i have a freind that has owned a 42 dodge with fluid drive for the last 30 odd years, it was restored in 1989, i know because i resprayed it for him , i have been on two long trips in the car with him , both were over 1000, miles, all he has run in the trans is ATF, and untill the first gear decided to expire ,which has nothing to do whith the fluid drive , he has had no problems whith he trans

[Guest Brady]

Frank, thanks for taking the time with such a complete answer. It was just what I was looking for. Right now the tranny is out of the car getting a complete cleaning and painting, the body is off the frame, and the engine is being rebuilt. My engine man is 65 years old, retired, just does engines on the side at his home. He was telling me about working on those fluid drives in his early years, but was mad that he couldn't remember what it needed.

By the way, he told me he hadn't worked on the dodge 230 flat head six in 30 years, but my engine made two he has rebuilt in the last 6 weeks.

Thanks

Brady

[skip1954]

I just had my 1941 Chrysler Royal converted from 6 volts to 12 volts, and I wish I had not listen to the mechanic, because now I can't get the transmission to shift up. I was told that the govenor burned out, using a voltage reducer, can anyone tell me what I can do to resolve this problem. Did they make a 12 volt govenor for the fluid drive in a newer model ?. Any advice I can get will be appricated

[Rusty_OToole]

You need a new mechanic. See if you can figure out what he buggered up and change it back. Or, at least get a 6 volt power source for all the 6 volt stuff he has not ruined. Hot rod shops sell power reducers or you could take a 6 volt tap off the center of the battery. By the way all 12 volt systems are negative ground and your car is supposed to be positive ground. Don't know what all that will bugger up. Go back to your so called mechanic and get all your 6 volt parts back quick. it could cost you hundreds of $$$ to buy new ones.

[Guest hiyudon]

My 42 dodge has the fluid drive tranny. That said, it appears to have ATF in it also. It has a slight leak which drips back to the shaft ebrake. Do any of those on the shelf additives to seal seals work? It's not worth dropping the tranny to fix this as I will only put about 1000 miles a year on the car. I will drain the ATF and replace with factory spec fluid or replacement.

Also, any ideas on how to deflect the fluid from migrating to the ebrake? I want to get this brake operable as this setup does not render it parkable on any type of slant, however minute...

[buick man]

Dropping the transmission is no big deal in these cars. I had a 1950 Wayfarer in high school and had to change the clutch, pressure plate and throw out bearing. Used a couple tube jacks and blocks of wood. Took about a full day to do the R&R. The transmission was not all that heavy. Of course I was lifting weights back then and nothing hurt. If I remember right, the fluid drive has an extended bell housing and inside in front of the clutch/psi plate assembly is the free floating torque converter coupling

[Guest hiyudon]

Thank you. Replaced a few tranny's myself in my day. Will get to this one someday, but not until the leak gets a lot worse...

[NTX5467]

Thank you. Replaced a few tranny's myself in my day. Will get to this one someday, but not until the leak gets a lot worse...

It could well be that if you drain the suspected ATF and put the correct fluid back in it, the leak might stop. That's been my experiences when getting ATF-filled power steering units filled with the correct Chrysler or GM power steering fluid. Something about the additive packages and such, even for similar viscosity of fluid.

Regards,

NTX5467

[NTX5467]

Weren't there different variations of the Fluid Drive? All had the fluid coupling and normal clutch, but didn't some have an "automatic shift", with the upshift orchestrated by a vacuum actuator when the throttle was let up on during acceleration?

Just curious . . .

NTX5467

[Guest hiyudon]

Yes, some did have the vacuum actuated shift. One of my questions is, what is the proper fluid replacement. I've had various suggestions, but can't seem to nail down a direct replacement which everyone agrees upon.

Thanks,

Don

[Guest Bob Call]

Consulted Chilton's Auto Repair Manual 1940 - 1953. For the Chrysler Corportion M-6 transmission with fluid drive it says "The Chryaler Corp. recommends that a top quality 10-W engine oil be used for operation down to zero tempature. Below zero tempature Chrysler Corp. recommends that 10% kerosene be added to 10-W engine oil for sub-zero operation ." Fill the fluid coupling and transmission to the bottom edge of the filler hole.

[Guest hiyudon]

Thank you Bob! All I could find was "Chrysler Fluid Drive Fluid" I'll put this in my maint check off list... Need to get that manual also.

Don

[NTX5467]

One thing to remember about the various non-motor/manual transmission/rear axle fluids used in those earlier times . . . they had to be something that was reasonably commonly available. Hence, brake fluid for convertible tops and what Bob's mentioned about 10W motor oil in the fluid coupling. From there, as long as the viscosity was agreeable, they could formulate the seals to match the fluid. Kerosene was also reasonably available back then, too, at many service stations.

No doubt, there were some other "non-approved" fluids which could be used, of the same general viscosity, but something that people had ready access too, as the hydraulic oil (probably from an agricultural or tractor's hydraulic system main use). Getting something to work, in a pinch, was more important, in their short-term situation, than exactly correct fluid . . . thinned or otherwise. Not unlike, as the Mopar police car book notes, the CHP's then-new maintenance supervisor started using 20W motor oil in their automatic transmissions, rather than ATF. Only rule was that after they got into a high speed pursuit, they'd bring the car in for a trans oil change. Seems that the TorqueFlites tolerated it OK, but the GM and Ford transmmissions didn't seem to like it as much. This was in the 1962+ time frame.

Just some thoughts,

NTX5467

[Guest Juan A. Cervantes]

Since this conversation is about the Fluid Drive Transmission, my 1949 Chrysler Royal's transmission is slipping when it's going up hill. Does any one have any advice on how to fix this problem? Or can any one give me any advice on rebuilding the trany? Any advice would be much appreciated. Thanks.

[Guest Bob Call]

Juan

Slipping is not a problem in the transmission as it is a regular 3 speed manual transmission that is electrically shifted. the slipping is a problem with either the fluid coupler or the clutch.

First, check the oil level in the fluid coupler. There is an inspection plate on the right side of the transmission hump of the floorboard. Remove this plate and you can turn the engine by hand or gently bumping the starter until the filler plug lines up in the inspection hole in the bellhousing. Pack rags between the bellhousing opening and the fluid coupler beore removing the plug. This is to keep from dropping the plug and having it go to the bottom of the bellousing. Remove the plug. The oil level should be at the bottom of the plug hole. If not, top off with 10W non-detergent motor oil. Most Walmarts have this oil and some parts stores. If this does not stop the slipping it is probably the clutch. Start by checking the adjustment of the clutch linkage. If the linkage adjustment is OK, my guess is that the clutch will have to be replaced.

[c49er]

What is a Fluid Drive transmission?

[Guest Juan A. Cervantes]

Juan

Slipping is not a problem in the transmission as it is a regular 3 speed manual transmission that is electrically shifted. the slipping is a problem with either the fluid coupler or the clutch.

First, check the oil level in the fluid coupler. There is an inspection plate on the right side of the transmission hump of the floorboard. Remove this plate and you can turn the engine by hand or gently bumping the starter until the filler plug lines up in the inspection hole in the bellhousing. Pack rags between the bellhousing opening and the fluid coupler beore removing the plug. This is to keep from dropping the plug and having it go to the bottom of the bellousing. Remove the plug. The oil level should be at the bottom of the plug hole. If not, top off with 10W non-detergent motor oil. Most Walmarts have this oil and some parts stores. If this does not stop the slipping it is probably the clutch. Start by checking the adjustment of the clutch linkage. If the linkage adjustment is OK, my guess is that the clutch will have to be replaced.

Bob, thanks for replying. Much appreciated. I'll start by telling you that I already had my experience with the filler plug falling into the bottom of the bell housing. It was a bear trying to get it out. I will check the oil level again and clutch linkage first but lets say that the clutch has to be replaced, can these clutches be bought at a clutch parts store? Or is it a hard part to find for these cars?

[Guest Bob Call]

You should be able to find a clutch assembly at any clutch and brake supply and probably NAPA. If all else fails you can get it from Andy Bernbaum at oldmoparts.com.

[Guest Commodore]

What is a Fluid Drive transmission?

See this link for a description of Chrysler Fluid Drive transmissions.

The Fluid Drive torque converter

[Rusty_OToole]

The Fluid Drive is supposed to slip to a certain extent. The manual says slippage goes down as revs build up also it will slip more under load as when climbing a hill. So if it is going up hill and not revving very fast you may notice some slippage.

At highway speed on level ground you still have 3% slippage.

Check the Fluid Drive oil level. It should be filled to the correct level with ISO32 or ISO22, TDH tractor fluid or 10W motor oil. It must be a thin oil to work right. Thicker oil has too much drag.

If the friction clutch is worn and covered in oil it could slip. In that case the engine could rev up quickly when climbing at full power. The clutch is not very big. It is an ordinary dry plate clutch like any manual trans car, but rather small. It can be replaced in the usual way after removing the transmission.

[Guest Juan A. Cervantes]

The Fluid Drive is supposed to slip to a certain extent. The manual says slippage goes down as revs build up also it will slip more under load as when climbing a hill. So if it is going up hill and not revving very fast you may notice some slippage.

At highway speed on level ground you still have 3% slippage.

Check the Fluid Drive oil level. It should be filled to the correct level with ISO32 or ISO22, TDH tractor fluid or 10W motor oil. It must be a thin oil to work right. Thicker oil has too much drag.

If the friction clutch is worn and covered in oil it could slip. In that case the engine could rev up quickly when climbing at full power. The clutch is not very big. It is an ordinary dry plate clutch like any manual trans car, but rather small. It can be replaced in the usual way after removing the transmission.

Thanks a lot Bob, Commodore and Rusty. I really appreciate your input. As far as the ISO-32 tractor fluid, I could not find it at Wal-Mart or at some of the auto part stores. What I did find is a fluid that is called Heavy Duty Tractor Hydraulic & Transmission Oil. It did not say anything about being an ISO 32 or 10W motor oil. Would this fluid be the same? Thanks.

[Guest Bob Call]

Juan

If your local Walmart or parts store doesn't have 10W oil, go to a Tractor Supply Company or Atwood's store to get ISO32 or ISO22 TDH fluid.

The fluid you found may be the same but you can't be sure if it doesn't say ISO32 of ISO22 somewhere on the container.

[Guest Juan A. Cervantes]

Juan

If your local Walmart or parts store doesn't have 10W oil, go to a Tractor Supply Company or Atwood's store to get ISO32 or ISO22 TDH fluid.

The fluid you found may be the same but you can't be sure if it doesn't say ISO32 of ISO22 somewhere on the container.

Thankyou Bob, I will do that. There's a tractor store near by. I will go there tomorrow. I appreciate the info, it's been of great help.

[Guest Juan A. Cervantes]

Bob, thanks for replying. Much appreciated. I'll start by telling you that I already had my experience with the filler plug falling into the bottom of the bell housing. It was a bear trying to get it out. I will check the oil level again and clutch linkage first but lets say that the clutch has to be replaced, can these clutches be bought at a clutch parts store? Or is it a hard part to find for these cars?

Bob, thanks for all the information that you provided me with. It was very helpful. After doing everything that you suggested, I took the clutch out to check it out and sure thing, it was the clutch. I took it to Clutch Masters and they rebuilt it for me. Now the car is driving very well. While I had the tranny out, I also took the hand brake to get it realigned. Thanks for the time you took to answer my questions.

[Rusty_OToole]

You probably know 10W motor oil is the same thickness as 10W30 at room temperature. ISO 22 is a little thinner, ISO 32 a little thicker. If the tractor fluid is like thin oil it should be OK. There must be some marking on the container, such as 10W or ISO32 or some other indication of what is in there.

[Guest Juan A. Cervantes]

The Fluid Drive is supposed to slip to a certain extent. The manual says slippage goes down as revs build up also it will slip more under load as when climbing a hill. So if it is going up hill and not revving very fast you may notice some slippage.

At highway speed on level ground you still have 3% slippage.

Check the Fluid Drive oil level. It should be filled to the correct level with ISO32 or ISO22, TDH tractor fluid or 10W motor oil. It must be a thin oil to work right. Thicker oil has too much drag.

If the friction clutch is worn and covered in oil it could slip. In that case the engine could rev up quickly when climbing at full power. The clutch is not very big. It is an ordinary dry plate clutch like any manual trans car, but rather small. It can be replaced in the usual way after removing the transmission.

Hello again Rusty. Rusty I followed yours and Bob Calls Advice about checking the slippage on my 1949 Chrysler Royals clutch. It was the clutch. I replaced it and now the car works fine (for its age, considering it's still all original). Thanks for yours and Bobs help on this. Much appreciated. Rusty, do you by any chance know where the stop light brake switch is at on these cars? My lights turn on but they do not flash when I step on the brake. Thanks again for your help. Juan

[Rusty_OToole]

The brake light switch is on the master cylinder or near it. It works by pressure from the hydraulic system. They are prone to failure when they get old and the Chinese replacements you get these days are not long lived.

Your local auto parts store should be able to get one for you, they are not expensive. If they do not have them in their system ask for one for a 1976 VW beetle, they are the same.

[c49er]

Brake light switch is behind the left rear tire on the inside of the frame.

Bob

[Guest Juan A. Cervantes]

Brake light switch is behind the left rear tire on the inside of the frame.

Bob

Bob, thanks again for all your help. I changed the clutch on my 49 Chrysler and the car is working great. Now the clutch doesn't slip any more. When I step on the gas the clutch grabs really good. I just took it to a car show that was about 45 minutes away from home and the car worked great. Thanks for all the information that you shared with me.

Juan.

[c49er]

What is a Fluid Drive transmission?

Old post...I know.....

I asked the question to see if some one would realize there is no actual "Fluid Drive Transmission"

 

But There is a.... 3 speed transmission thats used with the Fluid Drive couplings...

                            Vaca-Matic  Transmission      "                                          "

                            Simpli-Matic  transmission      "                                          "

                            Truck-O-Matic   transmission  "                                         "

                            Hydrauically Operated  transmission "                              "

                            Gyro-Matic  transmission        "                                         "

                            Presto-Matic transmission       "                                         "

                            Tip-Toe Shift transmission       "                                         "

                            Fluid-Matic transmission         "                                          "

 

And maybe a couple more I forgot..

I skipped over the Torque Converter cars from late 1951 -53

Bob.

[Rusty_OToole]

There is a Fluid Drive unit, and there is a transmission, they are 2 different things. This is too deep for a lot of newbies but I know the difference and observe it in my posts.

 

I might also note that you are NOT supposed to slip the clutch in a Fluid Drive equipped car. Release the clutch fully and drive it like an automatic. This is the reason so many clutches wear out prematurely. If you are used to driving a manual trans car you can slip the clutch and slip the clutch and it feels like it is doing nothing. But it is the Fluid Drive that is slipping as it is supposed to. So, don't drive like a manual trans, drive like an automatic and use the clutch as little as possible.

Edited April 7, 2016 by Rusty_OToole (see edit history)

[Guest jeffarch]

My 1947 CHRYSLER WINDSOR had a FACTORY METAL TAG on the side of the transmission that " SPECIFICALLY" calls for 10W Motor oil in the transmission gear Box. Being 1947 there was NO detergent motor oil, So that's EXACTLY what I would use in the gear box NOTHING ELSE, it might take a little doing to find it but it is out there.

[Guest Jack Harrington]

I have a 49 DeSoto that will not upshift. It was recommended that I start with changing the fluids on both the tranny and fluid drive unit. I recently drained the tranny and added fresh 10w oil. I have also purchased hydraulic ISO 32 "tractor hydraulic fluid" for the fluid drive unit but have no clue as how to drain and replace the fluid. Any recommendations would be greatly appreciated.

[Rusty_OToole]

Chrysler made no recommendation of changing Fluid Drive oil because it is a sealed unit. But I don't think they expected them still to be in service 60 years later.

 

There should be a removable plate on the bottom of the bellhousing. Take it off and bump the starter until the plug is at the bottom. Remove and let the Fluid Drive unit drain. Replace the plug, turn engine until the plug is in view in the access hole under the dash board on the right side of the transmission tunnel.

 

I like to stuff a rag around the hole so the plug can't fall in. Remove the plug and fill with 10W oil or TDH tractor fluid ISO22 or ISO32 grade. There must be an air space, they located the filler at the correct angle so you can't overfill.  Replace the screw in plug, kknockout plug, access plate and carpet. Go under the car and put the plate back on. Now you are ready to get in and go someplace.

[Guest Andyjon100]

Hello everyone!

I hope I'm putting this newbie q in the right place...

Can anyone tell me what Fluid Drive trannies were offered with O.D.? I'm in the (delicate) process of trying to buy a '49 first series Dodge Deluxe from a guy that restored it in the '80s. It's a VERY nice driver. He has 3 deuces, high compression head, mild cam, and a header on a rebuilt 230. Here's the issue. about 12 years ago, he decided it screamed way too much at highway speed, so he bought a supposedly rebuilt O.D. tranny . It turned out to have no reverse, so he put it away, and it's sat ever since. Now I have a good chance at buying it dirt cheap, as he needs money, but it's tough for him because he's had it since he was 18 years old.... I am trying to get some info on the trans and what the issue might be. I know I will need to purge the fuel system, go through the brakes, etc. and probably put the original trans back in temporarily if need be, but I want to run with the O.D.eventually instead of changing rear end gears... Any thoughts/opinions?

Thanks very much!

[Spinneyhill]

If O.Ds of that vintage still had freewheeling, it will have "no reverse" if the o.d. knob is IN, i.e. OD is engaged.

[Guest Andyjon100]

I'm not sure what vintage the trans he installed is....whether it's older or newer, however, That's giong to be the first thing I try after I get it running, and before I condemn the tranny.....Thanks ALOT! I've been trying to buy this car going on 3 years now, and It's close to happening. I even tried to get him to let me help him get it up and going for himself to drive just so it isn't just sitting there rotting away from the inside out, but drinking has gotten the better of him. He's now at the point he needs money and has been talking more about selling it. ( He's also got a '70 Dart GTS 340 sitting there in the same predicament).

[Guest Jack Harrington]

Thank you Rusty_OToole! This is just what I was looking for.