Adjusting Ford Transmission - FMX

My 1970 Cougar has a FMX automatic tranny and it shifts late (at partial throttle, engine revs up and it doesn't shift until it almost quits accelerating and then hits pretty hard. Is there a way to adjust? Does vacuum control this?

Thanks, bobby

Reply to
bob
Loading thread data ...

Reply to
Mike Walsh

I agree with Mike but you might want to check your timing and also vacuum level at the engine. I had a 72' Cougar the last year that they were made on the Mustang platform....I had a problem like yours that happened all of sudden, turns out that I had a vacuum leak at the EGR Plate that sits between the carb and manfold. Seems that the exhaust gas eats away on the neck of the plate that gos the the EGR valve....little pin holes show up underneath that neck where you can't see it. Don't blame the tranny yet!

HTH, Rick

Reply to
thetoolman

Thanks for the comments but there is no EGR plate nor ports. The intake is an after market Edelbrock and has no EGR ports. I have adjusted on the vacuum modulator but it didn't make much of a difference (put little screw driver up in the port the hose slips over). I will check for vacuum integrity. It is not losing fluid as it has run like this for several years. The kickdown is not stuck down as there is an extra return spring on it pulling it out (actualy, I don't think it is working as flooring it at

45mph doesn't make it kick down).

When I got the car it wouldn't go into reverse so I had tranny rebuild. I don't remember how it shifted before the rebuild but they did put a different valve body on it at that time from junk yard. I need to check vacuum but last time I did I thought it was a bit low (16 maybe). The cam is a bit higher lift and duration than normal. Would that (low vacuum) cause this sypmtom and if so, can it be adjusted for? Maybe my modulator is stuck since turning screw doesn't help much. I did have the vacuum hose pop off of the modulator once and it wouldn't shift out of 2nd. While I didn't do that on purpose, I assumed that meant it was working (low vacuum means stay in lower gear).

Again, thanks for any inputs.

Reply to
bob

Bob, if it suffers from low vacuum, you might buy a vacuum reservoir tank from a facility that sells/installs cruise controls. They help tremendously on small-engine cars which lose set speed on hills. And I've used several during older hot-rodding days for tranny-modulator lines when installing aftermarket cams. HTH, s

Reply to
sdlomi2

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.