Swap out FMX on a 302?

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Should be fairly straight forward. I was able to remove the FMX from my '70 351w powered stang without issue. Only thing that might be a problem is the exhaust getting in the way. Especially if you have an X or H pipe.
 
Thanks for the replies. What I'm getting is a thumping on the floorboard while in drive and foot on the brake. Everyone tells me that it's either the pump or the torque converter. I thought just replacing the trans, whatever the problem is would be better than trying to have it fixed. Thoughts?
 
Sounds like you've maybe got bad motor and/or transmission mounts. The FMX's are tough as nails, far stronger than a C-4.



i'll second that. i have no intentions of ever changing the FMX in my car for anything but maybe an AOD. the AOD is actually based on the FMX too, so basically it'd be like replacing my 3 speed FMX with a 4 speed FMX for the most part.

if you're getting a thunping sound on the floorboard you probably have a bad trans mount at least and probably at least one bad motor mount as well. my old jeep cherokee had all three mounts bad on it at one point, it's a wonder the engine never fell out, and i'd get that exact same thumping noise on the floorboard. changed the mounts and no more thumping.
 
Great information, thanks much. So, a bad motor mount would cause the thumping even if the car is just idling? Is there a way to isolate the tranny from the engine, say, plug the vac line and see if the thumping continues or goes away? How do I check the motor mounts? What would I look for to see if the tranny mount is bad?
 
i'll second that. i have no intentions of ever changing the FMX in my car for anything but maybe an AOD. the AOD is actually based on the FMX too, so basically it'd be like replacing my 3 speed FMX with a 4 speed FMX for the most part.

Notwithstanding that, there is not much of an aftermarket for performance parts for the FMX. Other than TCI, I don't know who makes a high stall torque converter for an FMX, and TCI doesn't make the best TCs out there. Want a steel six pinion front planetary for your FMX to handle the 450 hp your engine is making? Sorry, no such critter. No R servo equivalents like you would find for a C6. Etc, etc.
 
Your opinion of TCI stuff is just that---your opinion. The fact still remains the FMX was a better unit than the C-4. Just because the aftermarket bypassed them, doesn't mean they weren't. The aftermarket also bypassed the Cleveland too. And everyone knows it was the better hi-po motor platform.:nice:
 
Your opinion of TCI stuff is just that---your opinion. The fact still remains the FMX was a better unit than the C-4. Just because the aftermarket bypassed them, doesn't mean they weren't. The aftermarket also bypassed the Cleveland too. And everyone knows it was the better hi-po motor platform.:nice:

What I said was that TCI does not make the best torque converters. By disagreeing with me, you imply that TCI DOES make the best torque converters, and this is patently not true. They do make a decent TC for the money but not the best. This cannot be disputed.

Was the FMX a better unit compared to a C4 or C6 back in the day? Yes.
Was the Cleveland a better block compared to a Windsor back in the day? Yes

Given today's after market parts, is somebody better served with an FMX behind their engine or a C6? There is simply a much greater choice and availability of after market premium parts for the C4 and C6 and an enthusiast can build a far better tranny out of a C4 or C6 than he can with an FMX. This cannot be disputed.

My point is about choices TODAY. I originally had an FMX in my Mach 1 but the PO swapped it out for a C6 and I am glad he did.

I added low drag needle bearings in place of all the thrust washers. Not an option with the FMX

I got a sweet R servo that is not available on the FMX.

I got a low friction, low geared (2.71 first gear as opposed to a 2.46 first gear stock) 6 pinion, steel planetary for the C6 that can take the rigors of hard launches behind my 475 hp hot 351W. This planetary does not exist for the FMX. Is the FMX strong? Yes. But so is the C6, and there is a lot more after market offerings for the C6 and C4 than for the FMX, making these the better transmissions TODAY.
 
performance FMX parts?

convertors

http://broaderperformance.com/torque converters-A.htm

other stuff

http://broaderperformance.com/fmx and cruise o matic transmissions-A.htm

do a google search and you'l find even more stuff for the fmx. the fmx's biggest downfall is it's weight. as far as parasitic losses through the trans itself the fmx is on par with the c4 and the c6 is almost double both of them. the c6 is a great trans but it's an bigger pig than the fmx and weighs almost the same as the fmx, but yes there are more available parts for the c6 than the fmx, however the fmx will take almost anything you can throw at it with only minor modifications, the problem is finding someone who can still build an fmx these days but if you find a good old timer that does these transmissions you're all set.

really, unless you're running more than 400hp (like you are) all that needs to be done to the FMX is a good shift kit, a flex band and a mild stall convertor and that's it.
 
What I said was that TCI does not make the best torque converters. By disagreeing with me, you imply that TCI DOES make the best torque converters, and this is patently not true. They do make a decent TC for the money but not the best. This cannot be disputed.

Was the FMX a better unit compared to a C4 or C6 back in the day? Yes.
Was the Cleveland a better block compared to a Windsor back in the day? Yes

Given today's after market parts, is somebody better served with an FMX behind their engine or a C6? There is simply a much greater choice and availability of after market premium parts for the C4 and C6 and an enthusiast can build a far better tranny out of a C4 or C6 than he can with an FMX. This cannot be disputed.

My point is about choices TODAY. I originally had an FMX in my Mach 1 but the PO swapped it out for a C6 and I am glad he did.

I added low drag needle bearings in place of all the thrust washers. Not an option with the FMX

I got a sweet R servo that is not available on the FMX.

I got a low friction, low geared (2.71 first gear as opposed to a 2.46 first gear stock) 6 pinion, steel planetary for the C6 that can take the rigors of hard launches behind my 475 hp hot 351W. This planetary does not exist for the FMX. Is the FMX strong? Yes. But so is the C6, and there is a lot more after market offerings for the C6 and C4 than for the FMX, making these the better transmissions TODAY.

:D All this put down of the FMX is based on what you've heard (apparently) In this post, it's apparent you've never run an FMX, so all this is simply your opinion, not fact. Until you've run an FMX behind your 351W, don't be so quick to put it down.:nono:
 
Great information, thanks much. So, a bad motor mount would cause the thumping even if the car is just idling? Is there a way to isolate the tranny from the engine, say, plug the vac line and see if the thumping continues or goes away? How do I check the motor mounts? What would I look for to see if the tranny mount is bad?



bad mounts could cause the thunping even at idle. no way to isolate the trans from the engine as they are bolted together making them one unit, basically. you would have to put the car on jackstands and physically inspect the trans mount to see if it is bad.
 
:D All this put down of the FMX is based on what you've heard (apparently) In this post, it's apparent you've never run an FMX, so all this is simply your opinion, not fact. Until you've run an FMX behind your 351W, don't be so quick to put it down.:nono:

I am not saying the FMX is an inferior tranny compared to the C4 or C6. I am only saying that the aftermarket offers less choices for it and as such, you can build a better tranny out of a C4 or C6. As for Broader performance, that is where I got my low gear, 6 pinion steel planetary, wide bands, needle bearings, valve body, R Servo, etc. Jay at Broader Performace was very clear that given my build, a stock anything tranny wasn't going to last very long. These super hipo parts are simply not available for the FMX. Until they are, your choices with an FMX are limited.
 
I am not saying the FMX is an inferior tranny compared to the C4 or C6. I am only saying that the aftermarket offers less choices for it and as such, you can build a better tranny out of a C4 or C6. As for Broader performance, that is where I got my low gear, 6 pinion steel planetary, wide bands, needle bearings, valve body, R Servo, etc. Jay at Broader Performace was very clear that given my build, a stock anything tranny wasn't going to last very long. These super hipo parts are simply not available for the FMX. Until they are, your choices with an FMX are limited.



as i said a fairly stock FMX (with shift kit, flex band and convertor) will stand up to about 400hp, over that and it will need modifications just like any other trans, but put a c4 behind a 400hp windsor and you'll need a lot more than that, in most cases
 
Again, thanks for all the information. You guys certainly know your stuff! I'll check the motor and tranny mounts this weekend when the weather breaks and if I find anything I'll update this post.