Ford Vehicle Speed Sensors

[Land_That_I_Love_Project]

Ironically I have been working on the same issues, I have a 1999 4r100 with a NV271 TCase, and a 08 10.5 sterling rear axle. There is no hole on the 4wd extension housing for a vss sensor. I understand that quadvan has used the the rear abs sensor as a speed sensor for the vss. I would like to find the wiring diagram and the sensor that is used, if anyone could shed the light on that it would be greatly appreciated.

@tgreening Did you ever find the diagram? I'm dealing with the same issue. I have a Abbott Converter but we are not sure where to splice it in at. My rebuilt 4r100 does not have anywhere to plug in the other half of the harness.

 

[Bikersmurf]

On a speed sensor note... I’ve got a 12/96 E350 that’s speedo works fine... but under minimal load the cruise control sometimes surges at highway speed.

If I take over throttle control the problem disappears. The surge is very noticeable... not just sutle.., it’s the sort of thing that makes the everyone ask what the heck is wrong.

From what I’ve read it would seem it is due to a fluctuating signal coming from the rear axle VSS (ABS sensor) on the Dana 70.

For what it’s worth I’m leaning towards replacing the sensor on the rear axle. Thoughts?

@ujoint

Anyone else familiar with VSS systems?

 

[WinnieVan]

I believe the 08 10.5 Sterling has a 120 tooth tone ring in the rear extension housing.

I'm not sure what the stock number of pulses per transmission output shaft rev is on the 4R100... but the calculation goes like this:

OutputShaftPulsesPerRev = (120 * X) / Gear Ratio

Where X is the adjustment factor for your ratio adapter and OutputShaftPulsesPerRev is the number of pulses per output shaft rotation on the OE 4R100 for the vans.

Solve for X:
X = (OutputShaftPulsesPerRev * GearRatio)/120

For example -- if van's 4R100 is 7 pulses per output shaft rev and you have 4.30 gearing -- your adjustment factor is:
(7 * 4.30)/120 = X --> X = 0.2508

This makes sense -- since if your tone ring in the rear end is 120 tooth and your gears are 4.30 -- then it takes 4.30 turns of the output shaft to get one turn of the ring gear.

In the OE specification, the computer is expecting pulses from the transmission output shaft and since that turns 4.30 times per ring gear revolution -- that is 4.30 * 7 pulses = 30.1 pulses. However, 4.30 turns of the output shaft equals one turn of the ring gear which creates 120 pulses -- so if you adjust the number of pulses by from the ring gear by 0.2508 -- you get what the computer wants -- 30.1 pulses.

You just need to give the computer what it wants to hear...

So this begs the question -- does anyone know the number of pulses for the stock 4R100?

 

[WinnieVan]

Other info:

The early 4R100 just had a single VSS sensor -- later 4R100s have two. I don't remember when they switched over -- but it is the rear sensor that controls the speedo on the vans.

Also the van uses a gear driven speedo signal -- whereas the trucks use a tone ring and magnetic reluctance sensor -- also the trucks VSS sensor is in the rear pumpkin -- which I think has to do with the fact once you go into 4x4 LO -- the calculation above goes to ******** -- since the number of output shaft revolutions per ring gear revolution is adjusted by the 2.71:1 gear reduction in the transfer case.

In all reality -- I think to do this all perfectly -- you might need two ratio adapters -- one that is active in 2HI or 4HI and one that is active while in 4LO...

But what do I know -- my van is still on jackstands