Transmission Swap Questions

[87merc]

Okay, so I Have an 1987 Mercury Grand marquis 2 door, 5.0 with the AOD. Welp, the AOD took a dump and i have an FMX from a car and ive been reading about swapping the FMX to an AOD, so my question is, Can i do it backwards and go AOD to FMX? what would be needed. I'd rebuild the tranny but im 17 and flip burgers for a living so its kinda out of the question right now

[squirrel]

I don't think they ever made an fmx bell housing for the 302 did they? I could be wrong...

[cstmwgn]

289 - 302 should be the same bolt pattern. I suspect you will need to use the converter from the FMX and might need to modify the cross member and drive shaft as well. I converted from a C-4 to an FMX about 100 years ago but can't remember all the details.

[squirrel]

yeah, the details are the killer

[87merc]

thanks guys for the responses! i asked on a dedicated Marquis/crown vic forum and got alot of attitude for not knowing much

[squirrel]

yeah, they did make a bellhousing for it. early 70s.

http://www.ebay.com/itm/1973-1974-Ford-FMX-351-M-Automatic-A-T-Transmission-Bell-Housing-D3OP-7976-AB-/200985170392

sorry for the bum question.

The FMX uses a vacuum modulator as well as throttle linkage, and you need the shift linkage. You'll need to make sure the torque converter fits the flexplate. Cooler lines will probably need to be relocated. The driveshaft...I don't know how the length and spline compares, you should be able to get clues from the FMX-AOD swap info, or do some measuring. The crossmember might be in the wrong place? but it should not be a problem if you need to extend it forward. The dipstick tube might run into the floor, or something, so consider that. The 87 full size cars are similar to the late 70s full size cars, you might check to see when they last used the FMX in one, and that might help you figure out what else you might need or a source for it.

[Huskinhano]

yeah, the details are the killer

This^^^. Even if the trans is free and in perfect shape, it's the little things that are going to nickle and dime you to death. I'm pretty sure you'll be way ahead money wise buying a used AOD and swapping it out. Check Craigslist, I see AOD's quite frequently and cheap. Just make sure the fluid is red and doesn't smell burnt.

[Beagle]

I think the AOD and FMX flex plate are pretty much the same. That would be my big concern, getting the right imbalance if you have to change that. That should *more than likely* work for the trans spacer/backing plate that locates the starter as well.

Count the bellhousing bolt holes in the FMX and make sure there are six bolt holes. Very early SBF's used 5.
Measure the overall length of them both,
Might take a new crossmember
Might have a different driveshaft yoke
Might need the driveshaft length modified,
Not likely to have an easy way for the linkage for the kickdown rod to be attached
Rear end gear ratio is potentially high (depends on gear)
Speedometer gear / cable location
Shifter attachment
Vacuum source

is all I can think of off the top of my head. Like has already been mentioned, Ford used several bellhousing sizes for V8's, so to me, step one would be to verify it fits a 302. It's a heavy mother from what I remember, might be easier to take measurements before diving in.

[Russell]

A T5 might be easier.

[Deaf Bob]

It will be challenging enough doing your first tranny swap if you remove one and install same in it's place..
Then you want to go to a different tranny...
It will probably be cheaper in the long run to put in a junkyard tranny..

[Matt Cramer]

It will be challenging enough doing your first tranny swap if you remove one and install same in it's place..
Then you want to go to a different tranny...
It will probably be cheaper in the long run to put in a junkyard tranny..

Excellent advice. Pulling a transmission is a big enough production as it is.

A T5 swap would be cool, but I'd imagine finding (or more likely, fabricating) the parts to convert a Grand Marquis to three pedals is going to be pretty complicated. Another AOD would be your best bet if you're 17 and never pulled a transmission before.

[Deaf Bob]

Sell the FMX?
Are they worth anything to anybody but the nbrs matching crowd?

[Shelty]

I agree, Id hunt for another AOD. craigslist is your best friend. or if you have any junkyards near you. they put the AOD in damn near anything.

going to an FMX would be a downgrade, if it even fits. you are going to miss that overdrive gear.

like everyone else said, the small stuff will add up quick. when I put the 700r4 in my wagon, swapping from the powerglide, I spent a few hundred bucks to make it all go together. cross member, shift linkage, driveshaft, etc.

[Deaf Bob]

And remember, Shelty did it with common "everything fits" chevy, not "iffy Ford"

[anotheridiot]

dont forget dimensions too, even putting an overdrive in a regular tranny car will mean some tunnel work to get it at the correct angle.