I've just recently discovered the transmission I'm running in my F100 is an FMX- not the C6 I assumed it was. I'm not really familliar with this transmission. I'm wondering if anyone has any opinions on it- good or bad. I'm also wondering if it's worth putting any money into this transmission (need a new floor shifter) or if I should just "get-by-with-it" until I can find a C6. The drivetrain is from a 67 Ford with a 390 if that helps anyone form an opinion. Thanks, Jay
they are good trannys, but HEAVY thats why nobody uses them. I have one I am putting into a 1960 Panel truck behind a FE motor & the only reason I am doing so is that I got it for free and it is rebuilt. just do some Googling around and you'll find some good stuff on them
I just picked one up at the swap at the fairgrounds for 50 bucks. I heard they weren't bad but then again I haven't heard a lot. My friend has one in his 60 Starliner and hasn't had a complaint. I got C-6 if ya need it.....slim
I had one behind a 351w that I drove for 6 years and it never gave me a single problem, and shifted great, too. Look for a floor shfter out of a mustang or cougar to use.
I did a lot of burnouts with my 65 T-bird and I split the center inside the tranny. So the point where the bands were anchored to, pushed it apart when pressure was applied. So First and reverse were all screwed up. Just a stock 390, E-brock intake and carb nothing hi-po. I wouldn't advise one for hot rodding just based on my car but I am not educated on transmissions. I put in a Truck C-6 and have been happy with it. But I want to switch to a 700R4 when I get back to working on my car.
I'm on my third FE in my 59 F100 and still using the unrebuilt FMX behind the current mildly built 390. I've never had a single problem with it in six years.
Good trans for durability...bad trans for perfomance. They are notorious for having a heavy cast iron case, and few aftermarket internal upgrades are available, despite being put into the likes of '69 Mustangs with 351 Clevelands and Windsors. Few people make "performance" parts for it, yet it was put into MILLIONS of cars and trucks from the early '70's to the middle '80's. Usually was behind everything from a 302 in cars (late '70's) thru a 351M/400 in Broncos/Fullsize pickups (till the early '80's). I've heard it was an offshoot from the original cast iron "Merc-O-Matic" trans, which dates back to the late 50's- early 60's. I've had many of these in various cars, and have yet to have one go south on me...all have had various miles, etc...the highest un-rebuilt one I'd had was 25+ years old and had about 135,000 miles on it. It still worked as expected before the car was smashed and totaled. One weird feature...you can rev the engine up to as high as it will go in neutral or park, throw it in "D" and it will wait till the RPM's drop down before shifting into 1st gear. They are hard to grenade. Also, if you do, say, 30+ MPH and decide to put it in park, it will make a god-awful gear clunking noise...letting the car freewheel and roll, until it is rolling about 4 MPH, then it will lock up and stop the car. Mercman
I have one in my 69 Ranchero GT with a 351W 4 barrel. Absoluteley no problems in the 10 years I have had it. I used to tow cars all over So Cal, to Bakersfield, up and down long grades no sweat. The only reason I stopped towing with it was that usually the car and trailer were heavier than the Ranchero, so I had brake issues. A good transmission in my book. Its hard to find parts for and harder to find a guy that can build it. Call AAMCO and tell them you have a FMX
There are a lot of people who get the earlier transmission mixed up with the FMX. The FMX has the dip tube going into the cast iron case where as the Cruise-O-Matic has it going into the pan. (had another name, I think it was just FX). Other than that everything else I've read here is true.
Why take out a good trans to put a POS 700R4 in it? They dont fit on a 390 anyways, and if it did, they have a hard enough time dealing with a v6, then a smallblock chevy, let alone a 300+ HP 390.
Ive met a couple of guys who put 700 behind FE's as an alternative to the ford AOD and been happy with the results. I just want to try a Four speed Trans. When the car was running I drove it everywhere. It's not a hard swap. One guy even has a 390 with two fours and burly cam he hasn't hurt it yet. I like to try different things. Especially for my POS bird cuz I've already butchered the shit out of it. On the Fmx though, When I ran it(like 2yrs.) It shifted very nice. It was cheaper to switch to a newer trans(C-6) cuz the best tranny place around here had a bunch of dudes younger than me who told me they could'nt rebuild my tranny. But they gave me quote anyways(fuckers)
I've never seen it done. Interesting enough to see how they do it. Not that I would run a 700 behind an FE, but I do own a wrecking yard and every new option is of interest. I would think trans adapter, driveshaft and mounts would kill that swap for most folks, along with the $350 for the 700R4. I sell every one I get. Mostly to customers with Astro vans... Unless they are built up ($$) I still cant see them behind a 390.
Had one in my Ford PU for about ten years. Ran this hell outa that truck hauled loads way heavier than I should have. And never had a single problem.
the fmx is an improved version of the piece-o-crap cruise-o-matic. if it works ,id leave it alne.when it goes south ,put a c-6 in it.
Unless you're trying to break one they're as reliable as an anvil and just as heavy. I had one that outlived 2 engines with nothing more than a fluid/filter change and band adjustment...once. No one knows much about them because they never NEEDED to know much about them.
I've got one behind a '70 351C 4V motor, stock motor with 130,000 miles, 750 holley, headers and a pertronics ign., and the trannys held up fine.
Eary units were referred to as cast iron cruise'os. Not to much was changed in them before they were called FMX'S, somewhere around 1968, somewhere in that time line. Before then in the super late 50's a lot of them were installed in Thunderbird's, they came in 3 configurations too, commonly referred to as small, medium and large cruiseo's. Later in FMX'S the internal plumbing was reduced but they were still similar internally. They are a heavy duty unit with the rear planetary gear set making them superior to a C-6, whereas it has a rear roller clutch assembly and five to six clutches. There's where the C-6 is weaker than the FMX. This is why the old GM 400 is better than the GM 350 units. Also building the FMX is a pleasure to go thru, more so than a C-6. Also the FMX is one unit that I enjoyed mounting the converter to the engine flex plate, bolting on the bell housing section and starter, and then finally stabbing the FMX by itself into the converter like a standard transmission.
This thread is 13 years old but there may be someone else contemplating an FMX trans in their hot rod. I had a 49 Ford F-1 with a 67 Mustang 289/Cruiso. It worked good enough to break 2 rear ends in that truck. Never gave me any grief. Maybe it worked TOO good..
I recently put a 62 T-Bird "green" dot behind the Y-Block in my '56 Victoria. Damn thing will break your neck when it shifts if you get on it.. Looking to upgrade the rear end with an 8.8...
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