Alright guys, I have a 97 f150 single cab long box 2wd 4.2l with automatic transmision. From what I've figured out I have a open diff with 3.08 gears? Well I drive the truck to work a lot all highway. I changed my driving habit to less gas pedal and I set the cruise at 65 but the truck likes to down shift a lot even on the slightest hill. Am I doing something wrong or is this normal? Sent from my iPhone using Tapatalk
mine will downshift on slight hills, usually its just going from overdrive to 4th, not down to 3rd. The reason why it does it so it can keep up the speed with the cruise, if there is too much strain on the engine to keep it up to speed then it will downshift. my work truck was a 98 reg cab long bed with the 5.4, enough power to cruise at 75 all day and never dowshifting unless it was a really steep hill. Im thinking its normal since the little 4.2 its a weaker engine pushing a 1/2 ton truck. Has the truck been kept in good condition? anything that isnt running right like bearings/ball joints clean oil...etc can all create drag causing more resistance making the truck push harder to go the same speed.
Those old 4.2s didn't have much power. Is your air filter clean? check that with everything else that Jarrett mentioned. If you jack a wheel off the ground, it should spin freely and easily. You may have brakes dragging also.
Everything seems to be in working order , I just did a tune up, next on my list is fuel filter because I don't believe it's ever been chsnged Sent from my iPhone using Tapatalk
I don't know how normal that is? I used to have a 4.2 reg cab lifted on 285s which were big tires for that truck. I also had the 3:08s and never had a problem with downshifting at any speed on the hwy, even when towing. It didn't have cruise control though. My 4.6 extended cab will start downshifting a good bit towing 2 dirtbikes down the interstate at 70 with cruise control engaged, but its perfectly fine with it off. Its all stock on 265s so I've got nothing holding it back.
Mine doesn't seem to do it much without the cruise, but when I set the cruise it does it pretty often, it only jumps down one gear. And oddly enough I have never paid any attention but is my transmision a 5 speed or 4 speed? It's a automatic Sent from my iPhone using Tapatalk
Check out the hypertech programmer for the 4.2. Their about the only company I know off that makes one for the 97-03 4.2 motors. They advertise it to help stop random downshifting.