54 transmission swap std to auto

E

Earl Bancroft

New member
Gentlemen your thoughts and experience please. I have been asked by an owner of a 54 Ford to swap out the 3 speed standard transmission installing a 55 Merc automatic. Anyone care to weigh in?
 
You will need a steering column, replace all of the shift and clutch linkage, remove clutch pedal assembly and replace with a spacer, install starter lock out switch which may or may not be attached to the steering column, wire up the lock out switch, (intercept the wire that goes to the "S" post on the solenoid) change the brake pedal pad, The rear gear ratio is different on A/T from std. Std shift ratio is 3.55 to 4.11 depending on motor and trans; A/T ratio is 3.30. Note that the lock out switch also has provision for back up lights, don't let the 4 poles confuse you. the 2 bladed ones are the back up lights and the 2 round ones are for the starter interrupt. (I may have this backward)

Ford column is different from Merc. Do not attempt to use the std shift column as there is no feature to "hold" the shift arm in Park. What you really need is a donor car or you could spend a fortune buying all of the parts as you can see.

As you can see, it is a bit of work but the drive-ability will be much improved. Caution, now the wife can drive it!!! LOL
 
I did a similar swap in my '71 F100. Was originally 3-speed + OD. Went to a C6. Actually used the 3-speed column for several years until I acquired the correct column. Just left the clutch pedal on the floor until I got the correct pedal set for the AT. I learned to count the clicks to determine what gear it was in. No problem with it not staying in Park. Didn't change the rear end gears either, just made it pull a trailer like a champ.
 
Thanks to all replies. That's a lot of helpful ideas quick. What about the auto trans fit to engine block and what type of flex plate would be needed?
Any insight as to length and the need to modify the drive shaft. Thanks Earl.
 
On my '71 F100, I did an engine change at the same time. The engine and ****** came to me as a set, so no interface problems there. 360+3spdOD out; 429+C6 in. Did have to shorten the jack shaft a couple inches.
 
Earl Bancroft said:
..... I have been asked by an owner of a 54 Ford to swap out the 3 speed standard transmission installing a 55 Merc automatic. Anyone care to weigh in?
Click to expand...
Earl Bancroft said:
..... What about the auto trans fit to engine block and what type of flex plate would be needed? .....
Thanks Earl.
Click to expand...
If both car's engines are/were y-blocks the back end of the blocks and cranks should(?) be the same. If it's a straight six I don't have a clue. Does the '54 have a 239 in it?
'54 y-block parts don't always match up to '55 & later. But, I had a 'late' '54 block that was bolted up just fine to a '55 automatic (air cooled) .

Chances are a '55 auto trans will be air cooled. Get the bell housing, torque converter, the flex plate, any spacers & the flex plate crank mounting bolts (they're shorter) that go with the '55 Merc trans. If it's missing those parts you'll need to find ones that match up to the trans.

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The engine that was in front of a stick transmission will have a pilot bushing or bearing. It must be removed to put in an auto trans. If its a brass bushing, find a bolt about the same diameter as the hole, and wrap electrical tape around it to make it a snug fit. Pack the hole with grease, then hammer the bolt in the hole, after about three fills with grease, the grease will force the bushing out. Sort of messy, but easier than renting or buying a puller.
 
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