1993 VSS E4OD Question

[KenIDI93]

1993 Ford F-250 7.3 IDI, non-turbo, E4OD
If the VSS (Vehicle Safety Switch) on the rear axle should fail to operate/work (say broken wire) so the speedometer will not work/show mph's, yet the tachometer still functions (probably not involved with the speedometer, but letting it be known), would/could this affect the E4OD transmission operation in any way?
Why do I ask: had VSS failure, tach registers fine, speedometer not registering, and E4OD shifted a bit different (light on the automatic transmission column shifter began blinking, indicating something not right with tranny) and until the truck would not move anymore (no tranny power) it was then i realized the tranny cooler had blown a hose/line and had lost all tranny fluid! YIKES
Could the VSS not working/registering have caused the cooler to blow a hose and dump the tranny fluid?
I'm nowhere near a major mechanic, though do some stuff, so asking in here for opinions.
thanks all for your time...

 

[Rdnck84_03]

Yes the VSS (vehicle speed sensor) non operational will throw the transmission into limp mode. I know that in limp mode the pressures are much higher in the transmission, not sure if that equates to more pressure in the cooler lines though.

With the transmission in limp mode it will shift really hard, and at high rpm. The cooler line blowing could possibly just be a coincidence.

James

 

[u2slow]

I recall dealing with a similar trans problem due to the axle vss (vehicle speed sensor) failure on a '97 F450 some 20 years ago. I cant say if 93 and 97 behave the same.

 

[Rdnck84_03]

I cant say if 93 and 97 behave the same.

They should be the same. The 4r100 in the 7.3 powerstroke also behave similarly with a VSS failure.

James

 

[LowTech]

About those VSS, are there different ones for different gear ratios? My speedo reads 5mph faster at speed than I'm traveling.

 

[u2slow]

About those VSS, are there different ones for different gear ratios? My speedo reads 5mph faster at speed than I'm traveling.

No, because the tone ring spins together with the ring gear; which is always turning at the 'right' speed for the ratio.

5mph off (high) is pretty normal from the factory. A slight bump in tire size will get your speedo closer.