Auto Mechanic in the Forum?

wz2p7j

Jstas wrote: »

If the sensor is functioning but returning an incorrect reading, that will not show an error code. The operational voltage of teh speed sensor and any other sensor has to drop below or go above an allowable range to trigger a light. It is very possible that the sensor could be faulty but not returning a code.

However, if the vehicle does not have ABS braking, it is unlikely that faulty speed sensor would return a code in a 1995 vintage vehicle. OBD2 was not mandated on cars until 1997-98 model years. A 1995 Explorer is very likely OBD1 and does not necessarily have the accommodations to monitor vehicle speed in that way.

Jstas - I'm not familiar with Fords as I am a former GM service engineer so what you are saying may be true. However the diagnostics in 1995 across manufacturers were fairly sophisticated. I just don't see the speedo being that far off without tripping a code. I own a transmission shop as one of my side businesses. Maybe I'll have my guys look at Alldata and see what it really takes to trip a code with this scenario. Chris

AudioGenics

here is an interesting link....(trying to learn as this is applicable to my 4x4 TJ wrangler and oversize from stock and on ford 8.8 axle swaps)

http://www.explorer4x4.com/speedo.html

it would be interesting to know what your gearing is set up as
and what speedo gear is installed

Ford part # C1DZ-17271-A 20-tooth gear. A black gear.
The 19 tooth gear is a pinkish color.
$7.75

disneyjoe7

I have trouble believing this issue is electrical over being mechanical.

Read not a sensor issue. IMHO

gdb

If you can peek up under the dash or look at the trans/transfer case, see if there's a speedo drive cable used. (cable in this sense means a round housing w/ rotating flex shaft inside) If no drive cable is used-it's all electronic and needs to be hooked to an analyzer. Note: I think ABS systems are usually disengaged when 4WD is in used.

disneyjoe7

Before the sensor can "Sense" the speed of the vehicle the sensor as a gear thing

And I be looking at the transmission.

AudioGenics

I sure hope you consulted with your trusted professional because when I took the question to my "Chief Mechanic"

he did not want to guess and needs to physically diagnose the symptoms and determine the true root cause.

...MY BAD for sticking my opinion...

GOOD LUCK !... and let us know what the final outcome is !

rallyshark

I'm just gonna throw this one out there. I don't know how sophisticated the computer is, but.... If the truck had a chip or was programmed, some of the diagnostics can be disabled, and corrections can be made for different tire sizes/gearing etc. If the previous owner had a chip or programmer, they may not have removed the chip or flashed it back to factory. I know it's definitely possible with newer vehicles, but not sure about yours. If that's the case, then pull the computer and make sure there isn't a chip piggybacked on it, or if it can be flashed, have it flashed back to factory. I'm not saying that's your problem, but it's possible. Other than that I say speed sensor.

Motzart

Anyone know the specs for the diff gears on the speedo sensor?
One is Pink and one is a dark Purplish color.

The one in my 2dr sport is the Purplish color with the 235/75/15 tires
My neighbors He is junking is a 4dr with 225/75/15 tires is Pink.

Are these correct?

I haven't found any repair manual that tells the specs for the diff color gears.

sophie

gdb wrote: »

If you can peek up under the dash or look at the trans/transfer case, see if there's a speedo drive cable used. (cable in this sense means a round housing w/ rotating flex shaft inside) If no drive cable is used-it's all electronic and needs to be hooked to an analyzer. Note: I think ABS systems are usually disengaged when 4WD is in used.

Not true for the two GMC 4wd trucks / SUV's i have drove on ice.

Payton

Motzart

I found a place that has all the diff gears!

For Ford Ranger/Bronco II/Mazda B series and Explorer.

http://www.therangerstation.com/tech_library/Speedogear.html

disneyjoe7

So did that website help you any?

Motzart

disneyjoe7 wrote: »

So did that website help you any?

Some....I switched the gear from a purple to a tan but haven't tried it yet.
Before with the purple gear I figure when I was doing 70mph the final OD would kick in. That happens around 55mph.
Just a guess but I think someone toasted the original transmission and possibly swapped one from a 4dr that uses 215 or 225 tires.

My neighbors that is being junked.....the speed sensor electric plug-in had the locking ears broke off like someone switched it.
Someone put 235 tires on his and "I think" swapped in the tan gear to compensate?

I'll know more once I test it....was just to tired and sore last nite after climbing around on the hard floor.
Uggggggg :rolleyes: