Mercury Cougar Owners banner

1 - 12 of 12 Posts
D

·
Guest
Joined
·
0 Posts
Discussion Starter #1
Hi,

I was told my 69 Cougar has a FMX tranny. Is this a good fast tranny or should I look to upgrade? My friends 70 Cat has a C-? (Something another) and I want to be one step ahead of him. Any info is appreciated.
 

·
Registered
Joined
·
99 Posts
doc
pitch the fmx its not worth trying to go fast with
get a c4 or c6------the c6 may be hard to find the correct linkage for though
or if you want the gas milage go with an aod

or just go the good old way with a 4 speed

good luck
 

·
Registered
Joined
·
1,832 Posts
Doc, I disagree with Chris a little. The fmx is a fine trans within its limatations just like everything else has its limitations. It was designed as a mid range trans to fill a niche between the c4 and c6. It is not as strong as a c6 and for all out power handleing it wont hold up as well. It is a stronger trans than a c4 in my opinion with its cast iron case and heavy duty planitaries. The downside is that transco is the only source of shift kits for it (that I am aware of ) and performance coverters are getting hard to come by. The fmx is also not a ford transmission exactly, as it was made by borg warner, for ford. It just depends on what you want to do with it, but unless you plan on drag racing it or abusing it regularly with 500 hp holeshots it will make a nice street trans if done up by a trans man that has any experiance with it.( probably someone that is older than the 30 year old trans is ) I have run this trans personaly and have never had any troubles with it. My brother once run one in his torino street stock car for several years. He got his final drive ratio by running the car in only first gear at one track and second gear at the other track and he couldnt hurt this trans with a good hot 351c in front of it. I dont claim to be a auto trans expert as I have my uncle do my trans for me. He has about 40 years experiance doing transmissions and really likes the fmx's. I do like Chris's 4 speed plan but if you dont want to do the change over to a manual the fmx may be the ticket for you. For all out power handleing with a auto the c6 is best. Just something for you to think about.
 

·
Registered
Joined
·
1,102 Posts
FMX

My 70 came with an fmx and in stock form it chirped second, when I built my motor it seemed a little weak so I did what any gearhead would do and swapped in a toploader. I ran the toploader for years but wasn't happy with it so I just swapped in a AOD and I love it!!!! I have added a shift kit and it will spin when it shifts if you want it too and also increases your mpg. With 3:73 gears I tach around 1800 @ 60 so it is very streetable and has the lowend due to the 3:73's
Good Luck
 

·
Premium Member
Joined
·
2,048 Posts
I'm runnning my original FMX in my 69... Works great and handles the power no problem (~400hp - 351W).

I have a TCI Breakaway 2800rpm stall in it, and the transgo shift kit. Squawks through 1-2 and chirps through 2-3...
 

·
Registered
Joined
·
86 Posts
If you want to be one step ahead of your friend with the Mustang, keep the FMX--put in a shift kit. The money it'd take to swap in a different unit can be used on a part of the car that needs it more.
Unless you are going for every 1/10th of a second in the quarter, or making more then 500hp, a C-4 or C-6 will not offer any advantage over the FMX. All three of these trans have the same gear ratios and have a non lock-up convertor.
If you drive your Cougar on a daily basis or like to take it on long trips, then then only automatic swap that would benefit you is to use an AOD. The AOD is based on the FMX but has a 4th gear--an overdrive gear. When you go into overdrive you'll have a 33% drop in rpm's. The AOD generally provides about a 30% increase in highway fuel efficiency. In my 69 Cougar, I went from a C-6 and getting 15 mpg's on the highway to an AOD and was getting 20 mpg's on the highway. The around town mileage will stay about the same---depending on how often you get into overdrive. The AOD can be built to stand a lot of power, I am currently running one behind a 460.
Swapping to a manual trans is in your prefference of whether you'd like to shift or not.
Hope some of this info helps with your desicion,:cool:
 

·
Contributing Sr Motorhead
Joined
·
5,470 Posts
FMX trannies

There's nothing at all wrong with an FMX transmission. They have that cast iron case which should be stronger than the aluminum case of a C-4 or C-6. The FMX even has an internal center support bearing to limit the 'whip' of the internals under stress. Combine all that together and you have one strong-assed tranny. The limitations of the FMX are that performance parts are kinda hard to come by. Not impossible, mind you, just not as plentiful or common as the other trannies.

If you get the chance to look at the actual friction materials of the various transmissions, you'll see that the C-3 is a wimp, with the c-4 pieces slightly larger. Generally, the C-3 was used behind four bangers. The C-4 was used for sixes and small v-8s. The FMX was the in-between trans and the C-6 is considered the 'heavy-duty' Ford trans. (For the sake of simplicity, I'll ignore the C-5 which is a C-4 with a lock-up converter, and the various AODs.

Anyway, that said, I have a friend who runs a FMX behind his 71 Mach 1. No big deal, as his stock 351C-2V came with that tranny, but now with just a bellhousing switch, he is still running that same original FMX behind a 514-ionch stroker motor, and that car now runs in the low 11s. Of course, the tranny has had the usual upgrades like a shift kit and high stall converter, but it is still a FMX! It holds up quite well to its racing duty.

The real pros prefer running a C-4 for racing because it is lighter than either a FMX or C-6, especially when you get to rotating weight. The racers don't really care if they have to tear down and rebuild the C-4 a couple of times a race season, but I personnally don't particularly like rebuilding trannies all that much so I stick with the C-6s in my two 73 Cougars. Both of mine are 351C-CJs, one stock and one modified for street/strip.

I suppose what I am tryingto advise you to do is just stick with your FMX. It will handle just about all the power you can give it!

Good luck!


Cougrrcj
 
6

·
Guest
Joined
·
0 Posts
Discussion Starter #9
JJZ109

1st, note the screen name, year of the car, ok?

Anyway, my Dad had a '69 Cougar (351W) w/an FMX tranny, the frame bent, apperently it was part Jag (Leaping Cat Device), anyway, it sat around in my grandparent's back yard, one day, we went over, loaded the 351 into the pickup, took it home, after a rebuild it was crammed into a '73 Maverick (2 door of course), the 302 formerly in the Mav was put into the neighbor's Country Squire. The 351 had ripped that C4 (factory in Maverick) to within about 1 mile of its life, in about 2 months. The FMX with over 150,000 miles on it that was in the Cougar which of course was equipped with the ON/OFF gas pedal, never had a problem.
So, do whatever, thats just what I know about it. Personnaly, I'd get a C6, if you've got the green, a Street/Strip version (rebuilt & modified) from someone like B&M.
 

·
Registered
Joined
·
103 Posts
Trans

One other thing to consider is the C6 is a power hog.

Unless you need the strength because you are running 500+hp your going to actually slow down your car.

I've heard that a C6 can rob upto 50hp over a FMX.

C4 is lighter duty for small cars but like anything if you throw enough money at it..... it'll work.
 

·
Registered
Joined
·
1 Posts
DoctorPotion said:
Hi,

I was told my 69 Cougar has a FMX tranny. Is this a good fast tranny or should I look to upgrade? My friends 70 Cat has a C-? (Something another) and I want to be one step ahead of him. Any info is appreciated.
You want a C4 Tranny the fmx is too heavy, the C6 is not needed with a small block
there are cars witth 500hp with C4's in them

I run a C4 in my 69 with about 385hp. three years no problems
 
1 - 12 of 12 Posts
Top