FMX trans

[The Good Humor Man]

Hi All, In my 72 P350 I have a FMX trans, the motor is a 300 6. I have read some of the past posting on this trans, and not sure if I want to change it to a C6, I think the FMX is better suited for the step van.
When it is cold it has no problems. When it is hot, it slips, then clunks, or chatters when you start out. Reverse is the worst, when I back it back in the shop, I wonder if it will make it. After your moving, shifts great, and runs great, just when your starting out, and every once in a while, it chatters while at a traffic light, and you put it in neutral, then back in drive it stops chattering.
It is also leaking badly from the rear seal. I had the trans serviced, and was hoping for the best, but that and a can of trans doctor, has made it worse.
I brought it to my trans guy, and he told me to drive it until it dies, and wasn’t really to interested in rebuilding it, I think it being that the step van it is in is so tall, and he can’t get it up on his lift, and he isn’t a young guy anymore.
Does anyone know a fix for this, or should I look for another trans shop, I am not going to try a rebuild myself, and man has got to know his limitations, and I know mine.
Thanks in advance.

[bruski127]

I am rebuilding my FMX. There are still parts available. As it is I need to have some shiped.
The rebuild kits are available, however the bands are not, they need to be relined like brake shoes.
the people that do this charge a core charge on the old bands or just reline yours.
I was having trouble with all the gears slipping but reverse and high were the worst. It turns out the revese high clutch drum got hot and needs replaced. I found a guy here in San Diego County
who is getting me one shipped from Oregon. Plus still waiting on one band.
All in all the rest is good shape. It's either go to C6 and make all the drive train changes or rebuild.
Try searching for transpartsonline.

[The Good Humor Man]

Thanks for the reply.
I am pulling it out, and my trans guy said he will rebuild it for $450. He also told me that he could have it back to me in one day, I hope he doesn't have to ship for parts like you did, it would really screw me up.
Thanks again.

[brainfart3]

just swapped the cruise-o-matic for a c6 in my 67 250 w/352.
i wasn't able to find ANYONE in the area willing to rebuild a 40 yr old trans.
My son works for Checker Auto Parts - he couldn't find rebuild parts anywhere.

So we found a gently used '76 C6 and swapped it out.

issues:
1) had to drill holes in the frame to move the crossmember because C6 is 1.5" longer (2 drill bits @ $5 each)
2) shorten front driveline 1.5" so the center support could remain in the same location ($65)
3) new speedo cable - FMX had a screw-on end to the tranny - C6 had a slide-in unit ($20 at pick-n-pull)
4) adjust the linkage so P is P and D is D.

other than that - piece-o-cake!

[The Good Humor Man]

My problem is that my emergency brake is connected to the drive shaft right behind the transmission. It wraps around the drive shaft, instead of using the existing brakes.
I checked with my trans guy again this morning, and he said parts are readily available, except the tail housing parts. So I can just hope for the best, I am dropping the trans off on Monday, and have to have the truck running by Friday afternoon.
He has a spare C6 sitting around if the worst happens, but I hope it doesn’t come to it.
Thanks

[FordTruck]

I Awlyes Hear Those Trannys Are Good But That's Almost Exactly What The FMX In My Truck Does But I'm Changing It Out For A C4 Or C6.

[swissranger]

I also rebuilt the MX tranny of my 1967 F100. I found the parts at Transtar Industries: http://www.transtarindustries.com/
To my knowledge the bands are hard to find, normally they have to be relined.
Another supplier for vintage tranny parts is Fatsco: http://www.fatsco.com/products.htm

By the way, I got very good support from the guys at the Ford Transmission Forum: http://www.network54.com/Forum/260730/

Good luck
Roman

[The Good Humor Man]

Well mine is done, $803.00 to rebuild. The guy who rebuilt it said it was a Rube Goldberg, a Cruis-a-matic case with FMX parts. He was surprised it was still running with all the screwed up parts in it. The person who last rebuilt it really did a shoddy job.
He said it will last! I was concerned, but it works well, and next time it goes (if I own it) I will go the C6 route. The big problem with me converting is that the parking brake is connected to the rear of the trans, so then I would have to go without a parking brake, or redo the rear brakes to accommodate parking brakes.