I’ve got a '65 F-250 with what I think is the original Fordomatic, or “Green Dot” transmission. The rear band broke, so I don’t have reverse. I yanked it out and took it to my transmission guy, and he is skeptical if he can get a band (we did find one that was relined around 1970! ) that would be reliable, and he didn’t seem too enthusiastic about overhauling this beast anyway. He is proposing a C6 swap. He just happens to have one to rebuild that will be a bolt-in upgrade. Lots of money, however.
A guy down the road has a FMX just sittin’ there. Darn little money. Of course, he’s not too sure of its history. But its cheap enough to maybe take a gamble. (Edit: FMX is a 1970)
Can I bolt the FMX up to my big block bell housing and bolt on my truck tail-piece with the bolt-yolk and call it good? The mounting holes look right. The dipstick, linkage and lines are all in the right places. The cases look the same. What am I missing? What do I need to know?
Sorry if it sounds like I don’t know what I’m talking about. There is a real good reason for that.
Thanks for any help knowledgeable Ford people can give me. I posted this on a Ford messageboard and got… nothing…yet! I knew I shoulda started here. :smack:
Alright, IIRC and it has been years, the FX and the FMX were developed and replaced the Fordomatic. The FMX is the stronger of the two. I believe that they used the same case and dipstick housing as the Fordomatic. The valve body is different and the shift detents moved. Instead of PNDLR, you would now have the, now, more conventional PRNDL. The tranny will now start out in 1st rather then 2nd. The Fordomatic when in drive was a two speed tranny. To use 1st, you had to move the selecter into L for low.
If your friend has the FMX for sale cheep, I would try it. You have little to lose. Again, IIRC the tail housing and the bell housing are interchangeable. You may have to modify the shift linkage though. The big block may be a bit much engine for the FMX however, if the Fordomatic held up I expect that the FMX will also.
You might try using the reverse band from the FMX in the Fordomatic. I do not recall if the bands and drums were different or not. That way you do not need to change anything except the reverse band and of course the filter. IHTH, 48Willys.
Sounds like you have your answer, I have nothing to add except make sure you flush the cooler and lines or you could kill the new tranny in very short order.
I would assume the new trans came with a new torque converter but if it doesn’t consult the trans guy he can fill you in. Same with flushing the cooler.
I would stay away from the FMX, I have had two of them fail behind a moderately built 351C. A C6 is a much stronger transmission and is better suited for a big block/pick up truck combination. Ford developed the C6 for a reason.
You will need a different torque converter for each different transmission; they won’t interchange. New torque converters get filled with fluid prior to installation and I wouldn’t worry about flushing the cooler lines; there’s not a lot of fluid in them compared to what’s in the transmission itself.
fstbk1968, I’m pretty sure that the 351-C has a C-4 bolt pattern. I think that the 351-M/400 engines have big block bolt patterns, but it’s been a while.
This is for a stock truck; if the FMX fits an FE, then my guess is that it will work.
C-4s were used behind windsor engines which do not have the same bell housing bolt pattern as 351 Clevelands.
Ford engine families are a mess and the bell housings don’t interchange between them. That being said some transmissions came with different bell housings for different engines. FMX transmissions, IIRC, came with bell housings for 351 Clevelands, 351M/400, and 385 series big blocks, I didn’t think they came on any FE equipped vehicles (I could be wrong about that). So, the FMX might work for the OP if it came from a vehicle with FE. If not, he’ll have to get an adapter for the bell housing (if they make one) and he’ll probably have to adjust the length of his driveshaft too.
Personally I think the FMX was a rather crappy transmission and there are better options. I’d put a C4 behind a big block before I’d use an FMX.
It’s not about the amount of fluid it is about the crap in in fluid. Don’t forget his last trans grenaded and most like put shit all through the fluid. As you know the filter on an auto trans will kelp dogs and small children out of the trans but not much else.
Not flushing the cooler is begging for a valve body failure.
I’ve seen it.
I was crawling around under this thing today, and I’m now not too sure about a C6 fitting. The guy says that both crossmembers need to be moved, and that doesn’t look like an option with the Twin I-Beam front end. Everything kind of connects to that forward crossmember. I’ve got a '63 with straight axle that looks like it would take one, but that doesn’t help me too much right now…
I did finally get some input from the Ford Forum. Got some real specific advice for making the FMX fit. I’m not worried about it being strong enough for the 390 as this truck get driven pretty easily maybe once a month at most. Also found some good rear bands to stick in the one I have. Just gotta find someone willing to do it, or try it myself. :eek: I just want it put back together and out of the garage!
More research, more indecision, more stress. What I really want is Chip Foose to Overhaul me!
Good point. I was assuming that the old fluid was just dirty and maybe a little burnt, but you’re right; there could be pieces of metal other crap that will easily get past the filter.
I’m surprised that a C6 isn’t a direct bolt in; it was Ford’s heavy duty automatic and was standard in a lot of trucks. But I’m not really a truck guy and Ford Truck specific forums would be a better sources than here. If you are looking for more opinions, I’d suggest the Ford FE forum; lot’s of really knowledgeable folks.
Had the band installed by a “trans guy”, but he told me I had to remove the bellhousing/converter and go install that way. Told me I would blow up the pump! Scared the shit out of me!
Didn’t want to. Because of the the Twin I-Beam suspension stuff. Won’t bore you with that. Made the (possibly bad) decision to try to put it back in the way it came out.
It was cool today so I went’ out and gave it a try.
Using a motorcycle jack, lots of straps and blocks, got the thing to slide in like the proverbial “Greasy Dick” and it mated up to the bellhousing like it never came off!
I ran the 4 bolts in by hand, hooked up all the other shit and drove that Sum’Bitch! Easy at first, then kinda hard. Got the kickdown hooked up correctly. Stormin’! That 390 Rocks!
Got it good and warm, no leaks, no weirdness and it works in all three speeds that way and in one speed the other way.
I am a lucky Mother…
I didn’t even remove the driveline from the rear end!
