55 vicky transmission misbehaving

[delco1946]

So this past weekend was beautiful in Portland so i drove my 1955 Crown Victoria 292 with fordomatic. Its generally my daily if its not raining. once, it wouldn't go in reverse (last year) on a trip - likely unrelated to this weekends events. Its been beautiful, but cold (30-45 degrees). On two separate trips as i was accelerating, the engine would suddenly for split second rev higher almost like the load of the car was removed or the transmission was in neutral as i continued to accelerate. I would instantly ease off the gas and it would go away but this happened several times (although it seemed like after warming up this would stop).

Any thoughts as to why this occurred? Does it mean anything? I've never had any real issues with the engine or transmission except the one time it wouldn't go in reverse. Also, it does always take and 4-5 seconds to engage in reverse and engages faster/better if i pull the choke out a bit to bring up the rpms. Is there anything preventative i can do?

[darrell]

sounds like you need a fluid change.ive had newer ones that wouldnt go into gear on a cold morning till i tried a couple of times. a fluid changed fixed it.if you do take of the base and clean the screen.

[delco1946]

OK. Currently it shifts very softly/smoothly. Should i ask my mechanic to use a specific type of fluid to maintain this smooth shifting? Is that Type F ATF?

[darrell]

there are others here that know the type.

[Ole Don]

The symptoms say its low on oil.

[Ole Don]

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Try adding a full quart of ATF. It sounds like its a bit low.

[rotorwrench]

The FOM operates on pressure. There was no vacuum modulator till the 1961 Cruise-O-Matics came out. The Throttle Valve (TV) rod operates the pressure. More throttle equals more pressure since they correlate to each other. The TV rod may need to be adjusted to firm up the shift a little more. Soft shifts are OK as long as it doesn't slip. Slippage is indicated when rpm rises from normal as was previously stated. A low pressure situation like this indicates a need for a pressure test. The pressure should be tested through the range. Low pressure that can not be brought up within a little adjustment of the rod is generally due to some other problem inside. It can be a seal leak on a clutch piston or a band piston or even a damaged internal fluid tube or seal ring. In any case, that needs to be checked before the clutches get fried. Any slippage on a clutch will fry the plates if they are still the old metallic types.

If you do an oil & filter change, you will be able to quickly tell if something has slipped too much inside. The oil will smell burned and there will be metal in the pan. Clutches are steel and bronze in the old FOMs so the particles can be either. The bands can be adjusted too if they need it and the oil looks OK.

The Ford-O-Matics and the Cruise-O-matics both have a similar valve body. The fit of the valves inside the body it close tolerance. If any particles of crap get in there then the valves get sticky. When they are cold the valves get sticky. After they transmission warms up they work just fine but when still cold, they are quirky to shift. When they are right, they work really well but when something is wrong, they talk to you and it's isn't always a polite conversation.

[40 Deluxe]

If the engine suddenly speeds up when accelerating ("flares") when it is shifting into third, and doesn't go into reverse at times, it is likely a bad seal on the direct/reverse piston.

[Daves55Sedan]

The manufacturers recommended fluid is Type "A". If you cannot find type A, Dexron/Mercon fluid is the modern replacement of type A and it is available everywhere.

[rotorwrench]

Type F is the FoMoCo replacement for the Borg Warner series of transmissions from FOM thru FMX. Type A had whale oil in it as a friction modifier. That went away when they put a moratorium on whaling so the manufacturers came up with replacements at that time. Ford Came up with type F and GM stayed with their Dexron which was a modification of type B. Ford changed types with the C6 due to the change of clutch materials but the FMX still used type F.

Some drag racers used type F in their modified power glides to get a more positive shift. The metal clutch plates need a positive shift too. Conditioners can be added for the valve body function but that's about it.

[delco1946]

thanks for all the info. I think i am going to just print this threads, especially rotorwrench and 40 Deluxe's technical comments to give to my mechanic. My mechanic is great, but i think they might appreciate everyone's specific experience. I did a lot of research last night and my manual does say to use type A, and it does seem like Dexron is the modern equivalent. I may also just add that quart of Dexron, although i don't know whats currently in it. My research suggests that mixing F and A is not a big deal (?)Thanks everyone!

[rotorwrench]

A lot of Type F is marked as type F/A. Type A no longer exists in it's original form and since it is an obsolete type and no longer regulated they can say a quart is type A when it is in fact a Dexron type. It just depends on the company that does the blending and packaging. If you have doubts about what fluid to use just ask an old time transmission man.

[delco1946]

I finally checked my fluid level and when off, it’s slightly above full so problems due to low fluid are unlikely. It says on the stick to check when in idle but I’m doubting it makes much difference.

[KULTULZ]

The fluid must be checked when hot and in idle.

[miker98038]

Originally Posted by KULTULZ

The fluid must be checked when hot and in idle.

“Must” is the operative word. And “Hot” and “idle”

Many auto trans drain back and give bad readings when not at idle.

I was taught to warm it up, place it into reverse and drive, then neutral or park and check the level.

[39deluxecp]

try a can of 30w engine oil. it will thicken the oil and get you by until it is rebuilt to replace the leaking piston seal.

[delco1946]

So I checked the transmission while hot and after putting it in reverse, Park, Drive and it has plenty of fluid. Mechanic said it’s clean and looks good. So that is not an issue, but my mechanic did addofluid to the transmission that is supposed to help with that, I don’t know what he added it specifically. This morning while cold, transmission seem to be acting up again so I’m stumped. I can’t honestly tell if it is slipping, or Flaring as another member said. If it’s slipping type F fluid should help with that altho dexron ( type A) is more correct. Any other tests you guys know of to figure out why it’s doing this?

[40 Deluxe]

Originally Posted by delco1946

So I checked the transmission while hot and after putting it in reverse, Park, Drive and it has plenty of fluid. Mechanic said it’s clean and looks good. So that is not an issue, but my mechanic did addofluid to the transmission that is supposed to help with that, I don’t know what he added it specifically. This morning while cold, transmission seem to be acting up again so I’m stumped. I can’t honestly tell if it is slipping, or Flaring as another member said. If it’s slipping type F fluid should help with that altho dexron ( type A) is more correct. Any other tests you guys know of to figure out why it’s doing this?

"Flaring" is a momentary "slip". It usually happens during a shift. Instead of engaging a band or clutch pack quickly, an internal leak or worn clutch plates delay engagement. So as it shifts, a clutch or band releases normally, but since the next one engages too slow, the engine briefly revs up, or "flares".

On this trans it is very easy to do an air pressure check for leaking piston and servo seals. Get a shop manual which shows how to drop the valve body and which ports to blow compressed air into.

[Motorhead6]

The problem is that the seals are getting old and hard. Pust some Trans-Lube friction modifier in and drive for long enough to soak at operating temperature for at least 10 minutes. This will most likely give you a few more years of service. If you want to change the fluid, the Havoline Global Multi-Vehicle ATF will work in most vehicles just fine; including the old Fords. Let us know how this works out. Sounds like you don't need a fluid change, though.

[KULTULZ]

Originally Posted by delco1946

So I checked the transmission while hot and after putting it in reverse, Park, Drive and it has plenty of fluid. Mechanic said itÂ’s clean and looks good. So that is not an issue, but my mechanic did addofluid to the transmission that is supposed to help with that, I donÂ’t know what he added it specifically. This morning while cold, transmission seem to be acting up again so IÂ’m stumpedcanÂ’t honestly tell if it is slipping, or Flaring as another member said.

That's one good mechanic if he can analyze ATF off a dipstick.

You are beating yourself to death here.

1) The pan has to be dropped to see what lies on the bottom.

2) If no big pieces, you need to perform a manual flush to rid the trans/conv of trash.

3) The trans has to have the bands adjusted, period and confirm proper fluid pressure.

4) Check TV linkage adjustments and shift selector adj/bushings.

5) Need to refill with TYPE F (IMO) as it has a better detergent package.
Add a Trans conditioner.

6) Drive the car for a minimum of thirty days to hopefully allow the internal seals to swell and rid itself of varnish.

7) At the minimum, a drop and drain (another complete flush would be more beneficial).

8) If the trans does not operate correctly after this, it needs to go onto a forensics bench.

AGAIN- TYPE A fluid was replaced in the early sixties. DEXRON is the replacement (DEXRON III currently). Get your mind off of TYPE A. It's only use now is as a hydraulic fluid.