Truck sat for a few years because I did not have time or funds to fix .... so I decided to fix and put her back on the road.... thought I needed a fuel pump but was able to determine from reading here that my problem was a fuel pump solenoid. So truck is running now but when I took her out on the road the tranny will not shift automatically. Shifts manually into 1st 2ond and reverse but when in drive stays in 1st ????

Fuses under dash are ok .... but I noticed the speedometer is totally gone.

....checked connections on tranny and the sensor on the differential.

Any advice ?

Thanks

 

Well ok... I have been reading other threads on E4od trannys.

This thread in post number 4 claims a bad diode in alternator can cause issues https://www.ford-trucks.com/forums/1...-overhaul.html

.... My alternator light is on and not charging.

Also truck developed some tc shudder a while back causing an occasional hard shift

Truck has 112,000 miles and tranny worked fine before it was parked for 3 years

During the three years alternator died and speedometer stopped functioning.

 

Check your fuses, the cigarette lighter or the dome light is on the same circuit a the speedo and if the speedo is dead then the computer(PCM) gets no speed input signal and can't control the transmission correctly.

Was the dash cluster changed in this truck? The alternator charge circuit goes through the dash alt gauge and a cluster from a later truck isn't compatable, the cluster must be from an '89-91 IIRC.

PS. I just noticed you truck is a '90, in that truck the speedo is all mechanical(cable driven) so it has nothing to with the PCM or trans but still check all fuses and pull codes. A truck that has sat for extended periods can become targets for rodents so chewed wires are common.

 

Thanks for the advice. Dash cluster was not changed and there is no evidence of rodent damage. Neighbor has a code reader. I drove the truck in drive and went out on the road .... and as usual tranny did not shift ... so I over reved the engine and it did momentarily shift into second and then shifted out of gear before going back into 1st.

I will try and get codes

Tranny lost fluid when parked and I had to add 3 quarts .... and also some Sea Foam product for trannys....

Some friends try to suggest tranny is gummed up but I do not think so ????

I talked to a tranny mechanic and he doubted it was gummed up from sitting 3 years. He would diagnose the problem but I would need to tow it 5 miles to his location. I do have a tow bar.

 

Did you ever resolve this problem? I am having the exact same issue and nobody seems to know what it is.

 

I have a friend with a code reader ..... he has been a bit busy but said he would come over and read my codes... hopefully this week

 

You don't need a code reader. Ford OBD Trouble Codes ?

 

If your speedometer isn't working, it's likely the cable (or something inside the speedometer) froze, causing the drivegear to get stuck/break. If the speedometer drivegear breaks or is stuck, the speed sensor on the drivegear housing will not work either.

Without that sensor, the transmission will not shift.

 

Lead Head

Read post number 3 carefully....

Conanski says the mechanical cable driven speedo has nothing to do with the
PCM or tranny shifting ?????????

Thanks

 

I know what he said. The speedometer itself doesn't have anything to do with it, but the vehicle speed sensor and the speedometer are both driven by the same speedometer drive gear. If the speedometer cable or speedometer is seized, the speedometer gear will likely break, rendering both the speedometer and the VSS inoperable.

The speedometer cable goes into the back of the transfercase, and has an electrical connection it. That is the VSS for your year of truck.

 

Well ok

Truck was parked 3 years and speedo was functioning last time I drove it. I get it running again but do not take it out on the road.... just drive in the parking lot. Then I do other work on it and finally go out on the road and it does not shift.... and I notice speedo not functioning.

I hope you are right .... speedo needs fixed anyway.

Just found out my friends code reader does 1996 and later.

I will check out the speedo.

Thanks

BTW this truck is 2wd so no transfer case

 

Speedometer cable goes into the transmission tailshaft housing then.

 

I had a few spare moments today so I crawled under the truck and grabbed hold of speedo cable where it enters tranny. It was loose and pulled out .... actually I think it pulled apart but not where is was made to.

The black plastic part pulled off off from the metal part that goes into tranny housing. Plastic part has an electrical connection with 2 wires (similar to the one in the differential)

I would guess this is the problem .... the black plastic part separated from the metal part.

Here is an image (click to enlarge)

E40D, AXOD/E,AOD: VSS - Analog - E9TZ-9E731-AA

Bingo .... part fits 1989-91 f150 E4od tranny

 

Make sure the speedometer cable turns freely before you put it back together.