Help! Dead Speedo/No Overdrive!

[Garret]

Hello. I was driving down the interstate when my speedometer went from 65 to 0, evn though I was still going 65 (other gauges still work). Also, the tranny will not go into overdrive, and it seems to be shifting between the others at higher rpm than usual. Could it be a broken speedo cable causing the computer to not sense speed, leading to the problems with shifting and overdrive? Something else? All advice much appreciated.

 

[section525]

I know the 4R70W trannies use speed input to determine shift points and up/down shifts. Hopefully its the same with the older V6 trannies! I'd say definitely check the speed sensor.

 

[Crankcase]

The speedo cable goes into the transfer case on old explorers, so that shouldnt have any effect on the shift points...As for the overdrive...have you looked underneath to see if any wires are unplugged?

I know one knocks out the overdrive when unplugged.

 

[Opera House]

On the 92

the speedometer is driven by a mechanical cable. But it plugs into the VSS for the speed control so it uses the same gear drive. Maybe it stripped or cracked. Sounds like the first thing you should pull out.

 

[Garret]

Thanks

Thanks for all the input, everybody. Took the X to my local offroad shop and had them look at it. They said the housing where the speedo cable plugs into the tranny was broken, as if it got caught on something and ripped out while wheeling (last time was in November, so it held out for 2 and a half months). The OEM part to fix it is $95, but they somehow frankensteined it back together with zip ties, said the "fix" could last forever. Only had to pay for a half hour of labor. The speedo works once again, as does shifting and overdrive

 

[section525]

Wow. Great deal. Congrats.

 

[Jason_25]

Cool. Just an FYI but the reason your O/D and Torque converter lockup was not working was because on the 91-94 explorers both of these features are controlled by the computer receiving the vehicle speed from the VSS.

 

[Garret]

Just had another thought: even though the speedo cable housing was "fixed" with zip ties, will said cracked housing let water into the transmission? My Explorer likes to go swimming every once in awhile and I don't want water to go into the tranny. Should I buck up and get it fixed properly?

 

[Crankcase]

Water will defintley get it in there!!! Get it fixed properly before you ruin it for good!!