Hey guys i have a problem with my shifting on my f150, it is a 1995 ford f150 5.8L 4x4, my problem is it is shifting hard is most all gears, and downshifts hard at times as well, if i start my truck and drive it normally it shifts hard and the OD light flashes, if i start my truck and just put it into 2nd gear and drive around the OD light flashes after hitting like 3500 rmp like there is a code to be read, i brought it to a small shop that can read it for me and the truck didn't bring up any codes for him. Another thing is right after starting my truck and holding down the brake and just going though the gears it shifts nice with no clunking or banging, but if i drive it around for a little and come back home and do the same thing with my foot on the brake and going though the gears it shifts hard into reverse and hard back into drive. Also my speedometer is bouncing around as well, i dont know if that is why it shifts like this or not. I have tried changing the Speed Sensor and that didn't help with the shifting or the bouncing speedo, just wondering if anyone has had this problem or has anything for me to try. Im not by any means knowledge in mechanics but i can try anything that isn't to hard if you have any suggestions for me, i just dont want to bring it to a Transmission shop and have them change me up the *** or just say i need a new transmission if that isn't the case.
If the computer isn't receiving the signal from the VSS then the transmission won't shift right and the speedometer may not work correctly, so you were good starting there. A very common problem with these trucks is the wiring to the VSS, usually bad near the plug at the sensor.
I just went and checked the VSS wire just before it plugs in and there is green corrosion i can see, could that affect the signal? should i take the wire out of the plastic weather shied and see if there is any breaks or something further up the line? on another forum on this site people were saying to run a whole new line but i don't wanna do that if i don't need to. Also a forum was suggesting the Exciter Ring in the rear, could that be the culprit. I have been searching for days trying to figure out what to do, i almost ordered a rebuilt transmission just yesterday but for some reason i think thats not what is needed, thanks for responding and trying to help out a fellow F150 owner
Sounds more a throttle position sensor issue to me. If the computer thinks your foot is on the gas a bit, the torque converter clutch won't lock up. A new TPS fixed the exact same problem for me. It will also give you a rich air/fuel mixture if it thinks you're giving the pedal a little push when you're not, which may be the cause of your jumping.
As an electrician, I can tell you that if that green wire isnt broken yet, it's still conducting. Not that it doesnt need to be replaced, but inside that corrosion there will still be good copper.
ok ill check that out, nub question here, where is the throttle position sensor? And is it something i wanna buy new? or can i just go get one from an auto wrecker? Also do you know if there is any way of checking to see if that is the culprit?
ok i was under my truck following the wire back up to the front and there is this black wire just wraped and taped around the side steps, so i followed it up and it went into the truck behind the peddles into this little black box thing, it like a wiring harness box, it went into something called the shutdown input number 7 or 8 in the picture it was a grey wire, i dont know what it is or if its important or not, let me know what you think?