The Ford Barn

RalphG · 04-30-2026, 09:42 AM

After some searching I am not coming up with any info on the correct procedure to check the oil in the Merc/Fordomatic transmission in my 52 Merc. Online manuals do not mention it. I'm assuming it is checked hot, idling in park. Or is it neutral? Mine works ok with the oil very low on the dipstick but I don't want to over fill it using the wrong method to check.

corvette8n · 05-01-2026, 08:11 AM

I remember my dad checking his ‘53 Mercury idling in neutral after it was warmed up, not sure if that was correct. That car filled with 6 people pulled a boat almost every weekend on a 75 mile round trip.

JayChicago · 05-01-2026, 10:54 AM

Don't know diddly about automatic transmissions, but I think when in Park it is also in Neutral. So, either way, same thing. Only difference, Park inserts a mechanical lock on the output shaft.

RalphG · 05-01-2026, 11:03 AM

Thanks for the replies. It sounds logical that the flluid level should be the same in park or neutral. Maybe its just a safety precaution when they recommend park on some. Either way I think I will add some.

rotorwrench · 05-01-2026, 01:13 PM

For those that don't know, It should have a little floor plate on the passenger side (right) for access to the little filler stand pipe & dip stick. In 53, they changed to a dip stick tube in the engine compartment.

Just check on a level surface and fill to the full mark appropriate to the cold engine or hot engine just like the later cars. There is more info in the Merc-O-Matic manual than in the maintenance manual . I don't have a 1952 owner's manual but it may be in there. My 51 cars are both R10 overdrive models so I've never had to worry about it.

PS I went back to the M-O-M manual and it states to run the car in neutral for 4-minutes at idle then run through the gear selections to insure function and fluid distribution with the brake applied of course. Put the selector in park with the E-brake applied & engine in low idle and then check the fluid level. Fill to full mark an that's pretty much it. What confuses some about the 1P and later single range Ford-O's is that they start in Neutral and that low gear is manually selected. Low was for pulling when the car was heavy, otherwise the car could be operated in 2nd and high only.

RalphG · 05-01-2026, 01:47 PM

Sponsored Links (Register now to hide all advertisements)

Its true some think the Merc/Fordomatic have only two speeds but of course they have three. If you start in drive you are in second gear which is fine most of the time unless pulling a trailer or in soft ground.
Yes one of the few differences between 52 and 53 Mercs was the dipstick on the transmission. Mine is missing the original floor door and has a home made piece of sheet metal covering the hole.
Thanks for the info on how to check the trans. level. Its hard to read as the oil is so clean on that shiny dipstick.

paul2748 · 05-01-2026, 07:17 PM

What may confuse people on the 2 vs 3 speed FOM's is after 58 they went to a FOM with a 2 speed (I believe they called it a FOM)Then is 64 or so they went to the C4 which was a 3 speed.

rotorwrench · 05-02-2026, 12:08 PM

The F-O-M 2-speed had an aluminum case to tell it from the older cast iron case transmissions. The little 2-speed was designed for the little 144 6-cylinder and small block V8s before 1964. My Pop purchased a 1960 Comet that was supposed to be for the Edsel line of cars but ended up sort of being an "only" attached to the Mercury line at the halt of the Edsel that year. It was a dog. He traded it for a new 62 Meteor in late 1961. He couldn't wait to unload that Comet. It had the alien eyes for tail lights. It was basically an upscale with the Falcon's suspension and drive train.

04-30-2026, 09:42 AM	#1
RalphG Senior Member Join Date: Sep 2014 Location: Sask. Canada Posts: 2,619	Mercomatic Fluid Check After some searching I am not coming up with any info on the correct procedure to check the oil in the Merc/Fordomatic transmission in my 52 Merc. Online manuals do not mention it. I'm assuming it is checked hot, idling in park. Or is it neutral? Mine works ok with the oil very low on the dipstick but I don't want to over fill it using the wrong method to check. __________________ https://www.youtube.com/user/roosty6/videos

05-01-2026, 08:11 AM	#2
corvette8n Senior Member Join Date: Jul 2010 Location: 36 miles north of Albany NY Posts: 3,323	Re: Mercomatic Fluid Check I remember my dad checking his ‘53 Mercury idling in neutral after it was warmed up, not sure if that was correct. That car filled with 6 people pulled a boat almost every weekend on a 75 mile round trip.

05-01-2026, 10:54 AM	#3
JayChicago Senior Member Join Date: Jan 2019 Location: Chicago Posts: 1,028	Re: Mercomatic Fluid Check Don't know diddly about automatic transmissions, but I think when in Park it is also in Neutral. So, either way, same thing. Only difference, Park inserts a mechanical lock on the output shaft.

05-01-2026, 11:03 AM	#4
RalphG Senior Member Join Date: Sep 2014 Location: Sask. Canada Posts: 2,619	Re: Mercomatic Fluid Check Thanks for the replies. It sounds logical that the flluid level should be the same in park or neutral. Maybe its just a safety precaution when they recommend park on some. Either way I think I will add some. __________________ https://www.youtube.com/user/roosty6/videos

05-01-2026, 01:13 PM	#5
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 18,006	Re: Mercomatic Fluid Check For those that don't know, It should have a little floor plate on the passenger side (right) for access to the little filler stand pipe & dip stick. In 53, they changed to a dip stick tube in the engine compartment. Just check on a level surface and fill to the full mark appropriate to the cold engine or hot engine just like the later cars. There is more info in the Merc-O-Matic manual than in the maintenance manual . I don't have a 1952 owner's manual but it may be in there. My 51 cars are both R10 overdrive models so I've never had to worry about it. PS I went back to the M-O-M manual and it states to run the car in neutral for 4-minutes at idle then run through the gear selections to insure function and fluid distribution with the brake applied of course. Put the selector in park with the E-brake applied & engine in low idle and then check the fluid level. Fill to full mark an that's pretty much it. What confuses some about the 1P and later single range Ford-O's is that they start in Neutral and that low gear is manually selected. Low was for pulling when the car was heavy, otherwise the car could be operated in 2nd and high only. Last edited by rotorwrench; 05-01-2026 at 01:40 PM.

05-01-2026, 01:47 PM	#6
RalphG Senior Member Join Date: Sep 2014 Location: Sask. Canada Posts: 2,619	Re: Mercomatic Fluid Check Sponsored Links (Register now to hide all advertisements) Its true some think the Merc/Fordomatic have only two speeds but of course they have three. If you start in drive you are in second gear which is fine most of the time unless pulling a trailer or in soft ground. Yes one of the few differences between 52 and 53 Mercs was the dipstick on the transmission. Mine is missing the original floor door and has a home made piece of sheet metal covering the hole. Thanks for the info on how to check the trans. level. Its hard to read as the oil is so clean on that shiny dipstick. __________________ https://www.youtube.com/user/roosty6/videos

05-01-2026, 07:17 PM	#7
paul2748 Senior Member Join Date: May 2010 Location: Midland Park, NJ Posts: 4,406	Re: Mercomatic Fluid Check What may confuse people on the 2 vs 3 speed FOM's is after 58 they went to a FOM with a 2 speed (I believe they called it a FOM)Then is 64 or so they went to the C4 which was a 3 speed. __________________ 48 Ford Conv 56 Tbird 54 Ford Victoria

05-02-2026, 12:08 PM	#8
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 18,006	Re: Mercomatic Fluid Check The F-O-M 2-speed had an aluminum case to tell it from the older cast iron case transmissions. The little 2-speed was designed for the little 144 6-cylinder and small block V8s before 1964. My Pop purchased a 1960 Comet that was supposed to be for the Edsel line of cars but ended up sort of being an "only" attached to the Mercury line at the halt of the Edsel that year. It was a dog. He traded it for a new 62 Meteor in late 1961. He couldn't wait to unload that Comet. It had the alien eyes for tail lights. It was basically an upscale with the Falcon's suspension and drive train.