'72 Will No Longer Shift

PopsOtto,

There are about 60,000 original miles. I had the seals redone ~17 years ago. The only other real “maintenance” has been to check and top off the fluid in advance of using the vehicle.

I was following up on Grim’s last e-mail so that I could better aim my camera. It dawned on me the VIN would have the transmission code. Code “X.” Yep. FMX. Color me a light shade of embarrassed for not thinking of that earlier!

Eric

You can leave it ‘up’ as long as you want, if it’s supported that way! =)

As for your weepy FMX, the cure is annoying but simple: You probably need to replace seals.

From what you are describing, I’m going to bet it’s the front pump seal that’s the real ‘problem’ here, allowing fluid to leak out of the torque converter as she sits. But then as fluid levels in the rest of the transmission get overfull, it leaks out of other leaky seals like the shift select lever O-ring, and maybe even the filler neck seal.

Fixing these is actually super simple, but it’s also a pain in the rear, since you will have to 1) take the transmission out, and 2) have a nice clean worktable that can have messy transmission fluid poured all over it, and won’t mind having heavy metal parts drug across it.

Even an “empty” transmission that’s been drained is still a royal mess, and will leak red stuff all over the place when you work on it.

These transmissions are actually very simple to work on, for the most part, and don’t require a lot of weird tools. The basic seals and parts are also not super expensive. The FMX used a Ravineaux twin planetary setup, unlike the C4 and C6, but it’s still pretty easy to deal with. If you choose to work on it yourself, you might as well check to see if it needs its friction materials replaced, and put in a shift kit while you’re at it, to ensure long life and not have to get in there again for a long time.

Hope this helps!

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Thanks, Grim. It looks like I know what I am up against. Let me take a day or two and consider my options.

Aloha,
Eric

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2 things for you to help with your troubles. First, get the '72 FSM. They are dirt cheap on Rockauto and worth it’s weight in gold. Second, check out Ken Collins at Bad Shoe Productions. He has a video for FMX rebuild. Just pop it in a portable dvd player and follow along.

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Update:

Thans again for the continued help. Shortly after my last posting, I headed over to West Coast Classic Cougar to do some price checking on possible home repairs. That’s when I realized I had done something really, really, really stupid…As I perused the transmission section, I noticed that the dipstick was nothing like the one I had been checking. Then it dawned on me…I had been checking the power steering fluid level! Adding insult to injury, my daughter and I had successfully changed out the high-pressure line on the power steering system in the spring. Dumb, dumb, dumb, dumb…This was a critical reminder to always refer to the manual.

Today I put my self-loathing aside, got out my Chilton’s, and actually checked the transmission fluid…

…following the manual to the “T.” As expected, it was bone dry. I have put 3 quarts in as of now, and the ring at the end fo the dipstick is barely wet. I observed some smoke, but I think this was spills burning off the hot engine as it quickly dissipated. There is no obvious leakage. I understand that the FMX transmission takes 11 quarts, but I wanted to check here before proceeding. I am wondering if the level was low, I checked the wrong dipstick, and, with the known slow leak, the transmission simply got too low to operate.

There is one other point I should bring up. In my original post, I neglected to mention that the kickdown rod had become disconnected from the throttle mechanisms. I found the clip and reattached it.

Because I had assumed this was non-diagnostic, I left it out of this thread. Is it possible that this was loose for some time, exacerbating the situation, and then simply fell off just before the car effectively stopped shifting at all?

Thanks for the continued patience. I am going to sweep up the fragments of my ego and have lunch.

Enjoy your weekend!

Eric

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Corndog67,

Is this the product you recommend? More Information for DETROIT IRON DPRF2372SM (rockauto.com)

Thanks,
Eric

Yes. That’ll cover everything you will ever need to do to maintain and care for your cat. Good luck

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Be sure to only check the fluid in that transmission with the engine running. The fluid gets pumped into the converter and other places, out of the pan while it’s spinning. If you check it with the engine off, the dipstick will show that it has more fluid than it really does.

Don’t overfill it either; it will foam a lot, and do strange things!

And if you have a choice, use Type F. It works better in every way.

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This is from the 1973 shop manual. Hope this helps. If you need more let me know.

Thanks, Electric_Wizard. There are a few things here I can accomplish in my carport at home if refilling the transmission fails to get the car moving.

Eric

Thanks for the confirmation. It is on order. Shipping to Hawaii sucks, as usual, but it makes up for never shoveling snow!

Eric

HUZZAH!!! After loading transmission fluid quart by quart (and measuring with the correct dip stick…still feel stupid about that…) for a total of seven quarts since including last weekend’s additions, I got the old girl to move forward and backward! I got some smoke, but only when I spilled oil, based on my observation that the smoke dissipated after a few minutes. There is also a small puddle under the oil addition port, so I am pretty confident this smoke was from spillage.

This week will be one of observation. I shifted the wounded cat a bit her lair, so I should be able to tell a spill. Weather permitting, I’ll take her around the neighborhood. It is good and flat, so the kids and I can push here home (again) if need be. At a minimum, I hope that things are good enough I can get her to a garage and save the money on towing. There is no way I can safely drop the transmission let alone a way to set a “clean area” to work on it.

Very, very exciting…On to the rear blinker. Again!

Aloha!
Eric

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Update:

I backed the Old Girl out today. I only observed one small area of “fresh” transmission oil. After letting her warm up, I tested the transmission fluid level (NOT, I may add, the power steering fluid level!), and all was in order. I cruised around my flat neighborhood before taking her a bit further afield to add a hill to the test. All was well. Top speed was about 30 mph; average speed was about 35 mph. At the end of the cruise, there was no discernible drop in transmission fluid. I parked her back in her “lair,” and, at the suggestion of a friend, placed a piece of carboard underneath to better ascertain if new oil is dripping out our if I observed the last of the spilled oil seeping into the concrete.

At a minimum, I can drive her to the mechanic. In the meantime, as mentioned, I have to attend to the right rear blinker (again). At least I have my new shop manuals!

Aloha,
Eric

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Last Update (hopefully). The carboard bore some evidence of a slow leak. I think I am out of the woods…for now!

Thanks again for all the help along the way!

Eric

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