auto 4.6 extended cab 99. this transmission downshifts ALL the time! if i am cruising at 65 and set the cruise, it instantly downshifts into 3rd gear for about 1 second, then back to overdrive. If I am rolling downhill at 60 to 70 mph and push the gas down to maintain speed at the bottom of the hill, it downshifts again, even though there is no freakin load on the engine and I am allready going 70!!! Sometimes it just kind of slides between gears. dealer states it is functioning normally. anyone had experience with this? how did you convince the dealer this is not how it should operate? I mean, you have to drive the truck for awhile to pick up on this problem. HELP!!!

 

andrew s: Sounds like the torque converter control solenoid. Does your O/D Off light on the end of the shift lever flash on and off when this happens? If so, it has sent a code into the computer which Ford tech can retrieve to diagnois if this is the problem. If not, it could be the throttle positioning sensor is sending the wrong values to the computer. Either way, the tech should put the code reader on it and see what errors have occurred.

------------------
99 SC Sport, Silver color everywhere, 4.2 auto,3.55 rear gear, split bench, stock AM/FM @ 2 cheesy speakers w/Ford brand bedliner. Keep'n stock from the factory because we love it for what it is...One fine ride!

 

thanks for the reply j.b.. no, the light
does not blink, and the techs say no codes stored, all supposedly test fine. I have read that a dirty MAF sensor can cause tranny shift problems. anyone know abut this?

 

Your tire size has not change dramatically from the OEM on the door sticker has it?

------------------
2000 F-250 Super Duty, SuperCab XLT, Oxford white with medium grey cloth captains chairs, 5.4L Triton V8 (260 HP version!), 4R100 4 Speed Automatic Transmission, 4 wheel ABS, Deluxe Aluminum Wheels, Trailer Towing Package, Class IV Hitch, Reece load distribution system, Escort Sensor II Electronic Brake controller, K&N filter, Sure Stop towing skirt, "Westin" black powder coated step bars, "White-White" head lamps, Herculiner bed liner, ISSPRO Tranny Temp Guage, Excursion center console.

 

8% would make your 3.55 effectively 3.27. I wonder if it is confusing your engine's throttle map.

------------------
Y2K™

XLT SC SB 5.4L E4x4 AW-Disc, 3.73LS, Skid, 7700# HD Towing, Chrome LT-245, Steps, Captain's, 6CD, Tonneau, keyless, Toreador Red, called "Nick"

 

cphilip,

my tire size has changed from 235 16's to
255 16's, a differene of 8% in diameter.