Help after transmission replacement

[paradox1993]

So I bought a remanufactured transmission from shiftright. It's in a 2002 ford explorer sport trac 4x4 with the 5r55e transmission. Removal and reinstall went smoothly. But I took it for a test drive and noticed my speedometer is off. Like way off. I'm going 20 and its reading 80, that level of off. Any help would be great I want this truck back on the road.

 

[429CJ-3X2]

I did a search and looked in the wiring manual, and didn't come up with much. You might check every bit of wiring that was disconnected to swap transmissions, especially grounds.
Wish I could be more help, but that's all I've got.

 

[paradox1993]

Only thing I disconnected was the 2 o2 sensors on the y pipe, vss, iss, transmission range sensor, main transmission canon plug, transfercase motor, and starter

 

[oklagp1200r]

So I bought a remanufactured transmission from shiftright. It's in a 2002 ford explorer sport trac 4x4 with the 5r55e transmission. Removal and reinstall went smoothly. But I took it for a test drive and noticed my speedometer is off. Like way off. I'm going 20 and its reading 80, that level of off. Any help would be great I want this truck back on the road.

So did you call this company you bought it from and ask them?

 

[paradox1993]

Yeah but their main tech was out when I called

 

[429CJ-3X2]

One or two of the threads I found in my search mentioned the transfer case connection as the source of their speedometer problem after swapping transmissions. Their speedo problems were that it either didn't work at all, or it jumped around a lot, so they were having a little different issue than you, but related. Unplugging the transfer case motor and plugging it back in fixed their problem.

 

[paradox1993]

I might be really stupid. Is it possible my computer thinks I'm in 4 low when calculating speedometer readings and if so does anyone know if that is decided based on 4x4 motor position or switch position?

 

[429CJ-3X2]

Not stupid IMO. As to the first part of the question, I wondered the same thing after reading some of the threads I saw last night. That might be why unplugging the transfer case connector and plugging it back in fixed it for them. I can't answer the second part.

 

[paradox1993]

Not the problem hooked of forscan to the truck. 4lo is off. But on tire size it gave me rev/mile at 690. If my math is right that means it thinks I have 7.5 foot circumference tires. And I can't find forscan ability to change my tire size. Any ideas?

 

[Turdle]

29xπ÷12 equals what?

 

[paradox1993]

Ok well never mind on that part....yay math

 

[paradox1993]

Does anyone have electrical diagrams related to speedometers

 

[paradox1993]

Also what vehicles have that same transfer case

 

[410Fortune]

Rangers have same t case

Speedometer reading on a sport trac comes from the rear axle vss sensor directly to the 4 wheel abs computer. The abs computer sends the vss signal to the engines computer which then buffers the signal for the speedometer

The pcm can also use information from the iss and oss sensors on the transmission of the vss signal is not available

in my experiences if you had a bad vss sensor in rear axle or the wiring to it you will get a p0500 code after a few drive cycles

Check your wiring there is a plug that goes to the tmcase shift motor and then there is also a plug that goes from the trans harness to the rear of the truck this is speed sensor and reverse
Lights make sure that plug is good and tight all pins checkout etc

I have a couple of questions:

Was the battery disconnected during the transmission change?

Did you pinch any wires?

On this truck the transmission iss and oss sensors as well as the t case have nothing to do with the speedometer signal it is 100% calculated from the rear axle speed sensor

 

[paradox1993]

So problem solved my transfercase **** the bed and locked me in 2 lo without sending any signals out. Lesson learned.

 

[410Fortune]

So the shift motor went bad?

 

[paradox1993]

No shift rod stripped out and front drive gear stripped out too. Needs complete rebuild

 

[410Fortune]

So do you think the transmission was actually bad or was it the t case the whole time

 

[paradox1993]

Transmission lost od and second so tranny definitely needed work but the tcase may have played a part in the tranny going out