Ford Muscle Cars Tech Forum banner

FMX Transmission Questions

30K views 55 replies 6 participants last post by  vilis741 
#1 ·
Is there a specific FMX forum anywhere? I am have no first gear in mine behind a mildly built 390 or, in other words, it takes off in second gear and I have to lift a little to get it to shift into 3rd. The car has a B&M star shifter and it is adjusted correctly. I would like to fix what I have so I am pulling the pan to change the fluid and make an inspection of the innards. I did find a huge vacuum leak so i am working on sealing the intake up and replaced the vacuum advance that had a huge hole in. My question is where can I find the modulator? The kits I see don't have one and I can't seem to find one that would work.
 
#2 ·
The stock AT in a 65 with an FE was a MX. Of course you or your PO could have changed it out. But the stock 65 modulators are fairly common. My MX did the same thing and I tried several fixes including new modulator, fluid and filter, band adjustment, checking some valves, all to no avail. By then I was obsessed. I got a reman for $800 which has all three gears, but leaks.

Long story short, I don't feel much performance and I'm not sure I'd bother with it if I had the chance for a do-over.
 
#3 ·
I would change it for a C4 or C6 if I could find one with the right bell housing. I would also be open to changing it over to a 4 speed if I could find all the right parts at a reasonable price. I will play with it a little and see if I can get it working and try to find a different trans. Do you know if the C4 or C6 will require a new driveshaft yoke?
 
#4 ·
There is a transmission forum on Network54. Google Ford Transmission Forum. I ordered my modulator from bulkpart.com. I just looked and they don't have it on there anymore.

This is a silly question and you may have already tried this but have you tried taking off with the shifter in the "2" position. The position that is next to neutral on the aftermarket shifter will be "D" but on my car that is the "white dot", which starts off in 2nd. The next position, which would be "2" on your shifter is the "green dot" originally and should start off in first gear.
 
#6 ·
Regardless of what aftermarket shifter you use, the shift pattern of the transmission will remain as it came from the factory. That would make the gear identifiers on the aftermarket shifter irrelevant.

On another note, do you have any pics of your shifter installation and is your car bench or bucket seats? I've been thinking about adding a floor shifter to mines.

Sent from my STV100-2 using Tapatalk
 
#7 ·
Hello 65Galaxie_390,

There's still a great deal lacking on background information to help conclusively, but on the assumption that the transmission is either the original for the car or a pre-'67 original model transmission, then it uses the green dot, open dot (or no dot) drive shift pattern and what would normally be "Drive" on an aftermarket shifter is actually open/no dot and starting off in second is normal.

What would be "2" on your aftermarket shifter would be normal drive for these transmissions.

Again this is based on the fact that the transmission is an MX or FX and '66 or older. Since the FMX debuted in '68 it would have what is considered to have a modern shift pattern --> PRND2L and if you have this transmission then you have other troubles such as suck governor valve on tail shaft (somewhat common problem), valve body problems, etc.

Cheers
 
#10 ·
Yuppers, position "2" would be normal drive "green dot" on a pre '67 automatic transmission on the galaxies/Customs/LTD's. It doesn't matter if it's an FX, MX, C4, or C6. Like I mentioned earlier if you truly have an FMX transmission, since those debuted in 1968 then it's the modern shift pattern and your shifter nomenclature will be correct.

It's easy to tell if you have an FMX or an MX/FX series trans. If the trans fill pipe (dipstick tube) goes into the pan itself it's an MX/FX series, if the fill tube goes into the side of the case it's an FMX.

On the 'L' position of the pre'67 automatic transmissions, it can either hold second gear or first gear depending on speed and throttle position, so it's not totally the same as '1' on your shifter.

The pre '67 transmissions are called "Dual Range" and are kind of funky compared to the later more standardized ones.

Cheers,
 
#9 ·
There is still a lot on the car that I am working on fixing from neglect and I am not so sure the B&M Star shifter for the C4/C6 is the best choice. However, all the factory linkage and column shift is missing so I am not left with much choice. Anyone else have a B&M on their FMX?
 
#11 ·
Well sir, that would certainly answer a lot of questions. My tube runs directly into the pan and I just bought a non-returnable pan gasket and filter for an FMX which I can only assume won't work. You have been extremely helpful with this and I thank you. I am not sure what to do now since all the linkages are missing and it sounds like the kickdown cable is pretty important. The engine is more than stock so I may try to find a C6 with a stall or try to put a 4 speed in it. Thank you again for the information!
 
#12 ·
Hello 65Galaxie_390,

My pleasure to help. You said you're not sure what to do as you are missing parts. Perhaps if you post a couple of pics of what you have and what you want to do we can help further. Pieces like the kick-down cable, well actually it's a rod (tube), is easy to duplicate with 1/2" OD aluminum tube, a 1/2" tubing bender, hammer, file and drill. Not to mention a picture to get the general idea of its shape. There are typically two length kick down tubes, one for a 2bbl and one for a 4 bbl carburetor.

But I am curious as to what transmission you have, either the FX or MX. The FX is the lightest duty automatic out the bunch. If yours is the FX and your 390 is not stock, then I'd look for a C6 or MX. If it's an MX and it actually works, then I'd just see what parts are needed and use it.

Trying to find the medium length tail shaft C6 with an FE bolt pattern housing is getting harder and harder to find. Not to mention when you do find it, it's probably been sitting and needs to be refreshed for reliability. So the costs go up quite a bit since these parts are in the 50 year old category.

Just thoughts...
 
#13 ·
I will crawl under there sometime today and see if I can find a tag or at least take some pics. With the cam it has in it, it should really have a stall converter, but do they make one for the FX/MX? I don't want to overdo this because it really is just a street cruiser and have no plans on racing it. I have another car for that purpose. Again, this into is very helpful.
 
#14 ·
Hello again,

The FX and MX look so close to one another it's hard to tell the difference from the case but the pan is slightly different. Here's a link to look at if you cannot find a tag or it's missing.

Ford Transmission IdentificationPan gaskets and filters for C

As for the converter regarding stall. That's the main problem with these older Borg Warner designed transmissions (FX, MX and FMX) is that aftermarket parts and upgrades are slim to non-existent, unlike the C4 and C6. I rebuilt an FMX for a friend and he had a heck of time getting just rebuild parts. He had to send his bands in to get relined sort of thing because no one is making the bands from scratch.

Your best bet, if you have an MX and decide to stick with it, is to call around to some aftermarket trans places and see if you can send them your old converter and they can slice it apart, clean it, alter it for the stall you want, then they can re-weld it and balance it for you.

Even torque converters for the C6 mating to FE's apparently are getting scarce as the place I bought two rebuilt stall converters with Torrington upgrades required a core charge on the old converters, so I had to send them my two old ones, which is something you usually do not have to do for other transmissions.

As for rebuilding the FMX, after rebuilding a couple 700R4's, building up a 4L60E, a TH-400 and 2 C6's I was less than impressed with the construction and size (torque capacity) of the parts of the FMX. That's just my opinion though.

Good luck and keep us posted.

Cheers.
 
#15 ·
Ok, here is what I have. Trans numbers are stamped upside down, but read C5AP 7006 A on the driver's side. The pan has 14 bolts and is pretty much a rectangle. Fill tube is in the pan as you can see. I really don't know what I have to be honest. I can't find any other tags on it.
 

Attachments

#18 ·
From the pan it looks like an FX transmission, which is the light duty transmission. You can also measure the diameter of the slip yoke to confirm, the FX has the smaller yoke.

I know money is most likely a huge factor, but if you take it easy on your car, the FX will probably last for a decent amount of time (assuming the internals are in serviceable condition).

There are always options available if you feel your wallet burning a hole in your pocket :) there are adapters (pricey) you can buy to mate up other transmissions to the FE. Which if that's a consideration, why not go with a more modern overdrive automatic.

Food for thought.

Cheers.
 
#16 ·
#17 · (Edited)
Yeah, it's an FE for sure. The giant intake that is part of the heads tells me that. Anyway, I can find no information on an SX transmission and it looks to be a 14 bolt pan which some FMX's in old T-Birds had. Looks like the thread you pointed to is the exact same one I have. I am fairly confident that this is an FMX or FX, but still an oddball. I would really like to find a C6 now.
 
#21 ·
Hello,

The filter should be brass and just need a good cleaning (reuseable). Is your filter physically damaged? I do have two core FX's here if you need a used filter.

As for the kickdown linkage here's a link to one that should work.

66-71 Ford 390, 4V Full size car Transmission Kickdown Rod,Stainless Steel-NEW | eBay

The kickdown lever on the transmission is spring loaded in the non-passing position. So it gets pushed down when full throttle only.

As a side note if you're looking for a proper C6. Here's what to sort of look for.



This is a '66 C6, more or less, actually the case is a 70's replacement, but has the vent tube down the side and '66 dual range valve body.

If you end up with a '66 C6 with dual range you can just swap a later valve body into the transmission if you want the standard shift pattern. Up till the mid 70's will swap over, of course you'll still need to make sure it's calibrated for your car.

As there are different length C6 tail shafts this is the length for the galaxie.



If memory serves the more common FE C6 you'll find is from a 2wd drive truck, but those have a shorter tail shaft which means your propshaft will end up on the long side and prone to whipping if not made stout enough.

The other thing to note is where the shift lever comes out of the trans. In this case the lever is on top. This is for a floor shift. (This trans is for a 1966 galaxie 500XL with factory floor shift), if it's a column shift the lever will rotate about the bottom half instead of the top half.



Hope that helps a bit more.
 
#22 ·
This is some great info! I will pull the pan and give it a cleaning/look see then feed it some new fluid. I hope that takes care of it as this poor car has been neglected by the PO. The differential had chunks and sludge which may never have been changed so I will get things straightened out on her and report back. Thank you very much for the info on the C6!
 
#24 ·
Hi ShotRod64,

It wasn't till 67 that the pattern changed, although all the parts references I come across mention '67-1/2 so perhaps a mid year change? All the '66 galaxies with automatics we have (FX and C6) are open dot - green dot dual range transmissions.

Cheers
 
#25 ·
Here is an update with good news/bad news. The good news is that it is an FMX and it does have the dual range shift pattern. I put it in the D2 position and it does shift normally with the 1-2-3 shift. Although, it seems like it revs very high before it shifts, but it does shift. D3 (today's normal D position) is the 2-3 shift and first is low gear. The bad news is that under any load the car will spew fluid out the front and back seals, but if I take easy it seems to do fine. I know this because I had my son watch while I brake torqued the trans. Any words of wisdom on what might be happening? I still need to pull the pan and change the fluid, but I am wondering if I have a more serious issue.
 
#27 ·
Glad you found out that the "2" position works for you to get all three gears on the transmission.

As far as the fluid leaking, there are seals that hold the fluid in the transmission on the front and rear. The seal on the tailshaft can be replaced with the transmission in the car if you take the driveshaft off. It's less than 10 bucks. To replace the front seal, you will have to remove the transmission from the vehicle. That seal also cost less than 10 bucks.

If the filter was clogged, I would think that there would be less fluid flow, resulting in less leakage.

Rear Seal in this picture is at the very back of the transmission in the hole with the giant plastic plug in it.
 
#29 ·
I jinxed myself and now it leaks like all the time out of the front pump seal. I really don't want to pull the trans just for a seal. If I do that, I might as well rebuild it and if I do that, I might as well find a C6. Then I won't have to do this again and I can find a stall converter at a reasonable price.
 
#30 ·
Ford made it a lot of work to pull their trannys. The leak may be the seal but it may be the converter, too.
 
#31 ·
That crossed my mind as well. If the converter is junk, the line pressure might be causing the leak. I drove it 80 miles home and it didn't leak a drop. I take it out a couple of weeks ago and mash the throttle and she started leaking like crazy. Further fuel to finding a C6. Do you know of the trans mount is the same for a C6 as an FMX? Not worried about the drive shaft. I have Accurate Driveline Machine here in Indy that can make a new driveshaft or shorten what I have and they are reasonably priced.
 
#32 · (Edited)
Ok, my FMX gurus, take a look at this. Found where all the metal shavings came from in my pan and notice the big crack on the servo housing. The filter is only supposed to have one hole in it and it looks like it blew out the back of it! Anyway, any ideas what could have caused this? Where can I get parts? Can I do this in the car? The fluid looks good and doesn't smell burnt at all.
 

Attachments

#35 ·
Hello 65Galaxie_390,

Yes you should be able to swap them, however your friends is the FMX and you have dual pickups in your pan (looking at the rear pick up tube in the picture) which makes your trans an FX only. The FMX shares the larger slip as the MX, so you'll need the larger slip yoke, and then there's a potential question of tail shaft length difference which may require you to alter your propshaft.

Good Luck
 
#36 ·
Do you think the servo's are the same? I am still not sure I didn't screw up by removing it in the car. Can I get the servo back in with the transmission in the car? Last question, do the make an adapter to go from the FE to a newer FT C6? I can pick up a newer C6 for less than $100 here and cannot find an FE C6.
 
#38 ·
Hello again,

Dunno if the servo's are the same, as for the FT-FE I've never worked on an FT but everything I've read has pointed to the fact that the bell housing bolt pattern is the same. FT is just a bit more heavy duty (higher nickel content in block, forged crank, etc)

As a side note I have two junk FX's just sitting here, probably the servo's are fine if you're interested in just replacing the servo.

Cheers..
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top