Ford Crown Victoria | Mercury Marauder | Grand Marquis | P71Forum for discussion of the Ford Crown Victoria, Mercury Marauder, Mercury Grand Marquis and P71.
the problem is only when the car has to climb and hill , the car slows down so bad because it doesn't shift down unless i tramp on the gas.... if any thing its an annoyance , there must be an adjustment im just not sure where it might be. thanks for any ideas
what year car are we dealing with? the pressure is adjustable up by the throttle body on the fuel injected models from like 1986- early 1992 models still using the AOD. it adjusts the pressure of the transmission, but too low of pressure causes the clutches in the transmission to slip and making them wear out prematurely
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my 1986 Grand Marquis LS... Rose...
setting the trans pressure too low causes the transmission to shift early thru all gears... i had a bad rebuild done by Cottman transmission and the didnt set the transmission right... it shifted early and i complained about it... i set the trans pressure as high is it would go, but the internal settings they did were set too low and no matter the setting i did, it shifted too early... it would shift to the 4th gear around 40mph or so...
the shuttering you describe... when was last time tune-up, fuel filter and such been changed? i have had experience where bad wires and plugs made it feel like transmission issue... another thing possible is the TFI module on the distributor is on its way out. i had a friend change his after it died on him... after the change, he noticed that it didnt do things it did before... i would try tune-up and stuff to see if it helps and possibly go to junkyard to look for a good distributor that has aftermarket TFI attached or if not that, get another TFI and put it on
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my 1986 Grand Marquis LS... Rose...
Oh ok i see , yeah when i bought the car the old fella told me they put a new trans in it (new to the car) and i find it shifts to fast , and about the shuttering i put new plugs in it last year , air filter and distributor cap and button .. didnt touch the fuel filter , il replace that for good measure. il adjust the pressure tomorrow and see how it goes , should i put more tension on the cable or less ?
the transmission pressure is adjusted up by the throttlebody under the hood... it makes it easier to have a helper to do this... the gas pedal cable is just a simple clip to the arm and the transmission cable is connected by snapping into a plastic grommet... many times that grommet gets old and brittle and falls apart... i would get a set of grommets from the parts store located in the help section... ask a store employee if they have this section... if you want, you can get the brass bushing that locks the trans cable with a metal clip like a spring loaded u clip... get the bushing or go to a trans shop and see if they have the brass bushing for a AOD trans BEFORE attempting the adjustment...
when adjusting the trans cable, have the helper press gas pedal...
pull the cable loose from the throttle arm...
push the white tab up, the white wide part pops out...
then slide it back only a couple millimeters or so...
you dont need to adjust much, since the it doesnt need much movement to get more pressure...
i would repeat this process to get the shift you want...
toward front is less pressure, moving it toward firewall is more pressure...
again i say... too little pressure and it shifts early and burns up the clutches in trans
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my 1986 Grand Marquis LS... Rose...
did the adjustment , big diffrence in shifting , might need some minor adjustments but im happy so far, now i just have to figure out the shuttering o n the high way , i replaced the fuel filter it may of helped some but still seems to be doing it , my next guess would be the TFI ?
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