FMX TRANS, GONE BAAD

Mustang72ht · Mar 7, 2011

Hello

Im so pissed, becaus the fmx trans, on my 72 mustang is gon, and my mecanic said that its better to change for a C4 trans, what do you think?

Tnfastbk · Mar 7, 2011

Hello

Im so pissed, becaus the fmx trans, on my 72 mustang is gon, and my mecanic said that its better to change for a C4 trans, what do you think?

Which motor?

not2old · Mar 7, 2011

Hello

Im so pissed, becaus the fmx trans, on my 72 mustang is gon, and my mecanic said that its better to change for a C4 trans, what do you think?

Click to expand...

Which motor?

Roy My FMX is questionable also ..and I run a 351C 4V. Better to go C4 ..or bump to C6 and what mod's requirred?

Alan L

Steven Harris · Mar 7, 2011

I am not an automatic transmission expert and therefore am willing to learn but this is what I have gleaned. I ran an FMX in the 80's in my 70 GT Torino with a very potent 351 C (one that could pull the front tires) and never had problems. What I hear is that an FMX is on par with a C6 only heavier due to its cast iorn housing, which is the main reason to run a C4 or a C6. Nowadays I am sure parts availability is also a big issue as most high horsepower applications use either the lesser weight of the C4 or the strength of the larger C6. I run an FMX now with a 351 C 2V but hope to change over to a 5 speed for the sheer fun of driving one.

not2old · Mar 7, 2011

Thanks for the info

Alan L

thundertc64 · Mar 7, 2011

Me i like the FMX,they can handle up to 500HP and they eat the least amount of HP doing it. Had FMX in my 72 it started slipping i pulled it out rebuilt never had any problems with it,until i busted the case on it

droptop73 · Mar 7, 2011

The preferred automatic for NHRA stock eliminator Fords is the C4. It is lighter and has less rotating mass.

I'm planning on running an AOD in my Convertible.

By the way, reducing driveline rotating mass is the most effective way to gain performance.

Steven Harris · Mar 7, 2011

Yes, the AOD would be an excellent option at this time.

thundertc64 · Mar 7, 2011

The preferred automatic for NHRA stock eliminator Fords is the C4. It is lighter and has less rotating mass.

I'm planning on running an AOD in my Convertible.

By the way, reducing driveline rotating mass is the most effective way to gain performance.

You are right, If I remember right I'm not 100% sure i could be wrong on these figures FMX = 24 HP,C4 = 27 HP, and C 6 = 40+ HP used or Lost.Been awhile since i have read up on it.But to be honest the last C4 tranny i had ruined me on them.

Tnfastbk · Mar 7, 2011

I'm no expert in this field either but c6 seems to be the automatic of choice around here. Not heard of many ever switching from a c6 to a c4. But like I said I personally have not done my homework on this subject just going off what I know from being around ford guys all my life.

http://en.wikipedia.org/wiki/Ford_C6_transmission

http://en.wikipedia.org/wiki/Ford_C4_transmission

http://en.wikipedia.org/wiki/Cruise-O-Matic

danoreilly · Mar 8, 2011

I personally LOVE my FMX in my '71 Mach. With a shift kit, it shifts exactly as I like it to and does everything I want it to. I had mine professionally rebuilt for less than $1k, and I'm sticking with it because it's the original tranny in a numbers-matching car. But even without that, I would still go with the FMX. Yeah, it's not as ubiquitous as the C4, but it's still a great tranny.

BigPinoyHunk · Mar 9, 2011

people even with 460's run 1000 capabile horsepower c4's. however, if i'm not wrong, i believe the FMX and the C4 uses the same slip yoke and cross member. best bet is to just switch to a c4 because you have all of the part already. switch to a c6 and you'll need to change the cross member, slipyoke and etc.

take that into account! if your willing change everything out anyways, they have entire AOD kits out there. i was almost going to do a 460 AOD kit if i didn't find a clutch pedal assy. i forgot the company but its in mustang unlimited's catelog and..........its also listed www.summitracing.com as a entire kit. if i remember, i was like 3100 for a BBF kit that is a custom build because the cut off the bellhousing and bolts on a 385 series bellhousing and has a custom converter.

coilwire · Mar 9, 2011

I blew second gear out of 2 FMX's. I went with a C6 and have had no trouble. Wish I would have gone with a C4 tho. The C4 does not rob as much HP.

Jim

jorgem2 · Mar 9, 2011

Hello

Im so pissed, becaus the fmx trans, on my 72 mustang is gon, and my mecanic said that its better to change for a C4 trans, what do you think?

I would recomend rebuilding the FMX, the C4 uses a different yoke and a different crossmember. the FMX is a very durable tranny and there are plenty of rebuild kits and street strip style parts and converters for it, just check the internet or ebay. If you are going to an all out race set up then go with the C4 for all the aftermarket stuff. If your are staying below 500 hp you cant go wrong with the FMX.

Describe what happened to yours maybe it not shot, but someting else

not2old · Mar 11, 2011

Thanks Guys. I've been out of HP cars for too long. 40 yrs ago I built BIG BLOCK Chevy's because thats what the rich kids drove because they blow up small blocks. They called FORDS too costly because nothing was interchangable like chevy's engine parts, so they could swap pieces when they blow them up street racing.

snoozingpony · Mar 11, 2011

it really depends what your going for aod is nice but can be diabled but simply overtightning the tras filter durring service fmx is not a bad trans and is direct replacement (recomended) / c4 small light tough as nails great trans may require drive shaft modification/ c6 overkill big heavy drive shaft modification/ I would rebuilt and beef up the one you got take it to a good trans shop have them up grade it and get a good converter you won't be disapointed. If you have some tech nical knowledge and lots of tools you could get a good manual from b&m and build it to there specs normaly you can fit one extra clutch and steal in the clutch pacs and still stay in specs for free play. this is a good idea. but warping a steal to take up the slack is a bad idea.

just my 2 cents

Nick Steger

73vertproject · Mar 11, 2011

it really depends what your going for aod is nice but can be diabled but simply overtightning the tras filter durring service fmx is not a bad trans and is direct replacement (recomended) / c4 small light tough as nails great trans may require drive shaft modification/ c6 overkill big heavy drive shaft modification/ I would rebuilt and beef up the one you got take it to a good trans shop have them up grade it and get a good converter you won't be disapointed. If you have some tech nical knowledge and lots of tools you could get a good manual from b&m and build it to there specs normaly you can fit one extra clutch and steal in the clutch pacs and still stay in specs for free play. this is a good idea. but warping a steal to take up the slack is a bad idea.

just my 2 cents

Nick Steger

Good advice, Nick. Hey, let us give you a proper welcome by posting a brief intro in the Introductions section. Glad you found us.

Doc

snoozingpony · Mar 11, 2011

it really depends what your going for aod is nice but can be diabled but simply overtightning the tras filter durring service fmx is not a bad trans and is direct replacement (recomended) / c4 small light tough as nails great trans may require drive shaft modification/ c6 overkill big heavy drive shaft modification/ I would rebuilt and beef up the one you got take it to a good trans shop have them up grade it and get a good converter you won't be disapointed. If you have some tech nical knowledge and lots of tools you could get a good manual from b&m and build it to there specs normaly you can fit one extra clutch and steal in the clutch pacs and still stay in specs for free play. this is a good idea. but warping a steal to take up the slack is a bad idea.

just my 2 cents

Nick Steger

Click to expand...

Good advice, Nick. Hey, let us give you a proper welcome by posting a brief intro in the Introductions section. Glad you found us.

Doc

thanks sorry about the small highjack of the thread

73vertproject · Mar 11, 2011

No worries at all.... we do it all the time. :angel:

Doc

FMX TRANS, GONE BAAD

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