Backcountry Pursuit
Risk Taker
Howdy Expo land!
My MG conversion is in the very last final phase and I still have one big dark cloud left. VSS. Here's the quick story of how I got in this mess.
I pulled out my 2WD E4OD from the van and replaced it with an E4OD out of an Expedition 4WD. This Expedition popped up on CL for a part out and $300 for a complete tranny was a hell of a lot cheaper than rebuilding the entire transmission to convert my 2WD to 4WD. I got to drive the Expedition before we tore it out and the tranny was great. I slapped it in my van and I ran into a problem. There was no connector on the tail housing for the VSS! Turns out the Expeditions pull VSS from the T-case UNLIKE the truck E4OD. It appears to be the only difference between them.
Here is how we are planning to solve this and I would like validation from the community we are headed down the right path and hopefully good input on figuring out the math. We plan to splice into the ABS signal wires coming from the rear differential of the Sterling 10.5 and run the wires through the AB001 signal converter I got from Ujoint to the van VSS plug. We need to come up with the proper factor to divide the signal from the rear diff by in order to show the PCM what it expects to see for how fast the van is actually moving.
Known information:
Ford PCM expects to see 8000 pulses per mile. This according to MG and I am inclined to believe he is correct.
Wrangler Duratrac 315/70-17 tires turn 607 revs per mile per Goodyear specs.
Rear axle ratio is 4.30.
Sterling 10.5 has 60 tone ring teeth.
Questions
1. Is the tone ring attached to the ring gear? If so, where does the 4.30 ratio figure into the equation?
2. Does the ring gear turn once per tire revolution? Driveshaft turn 4.3 times per one ring gear revolution?
MG figured it this way.
607 tire revs x 4.3 driveshaft revs per tire rev = 2610.10 driveshaft revs per mile.
4.3 x 60 pulses per tire rev= 258 pulses per driveshaft rev.
2610.10 driveshaft revs per mile x 258 pulses per driveshaft rev = 673406 pulses per mile.
673,405 / 8000 = 84.
We need to divide the ABS signal by 84 to show the PCM what it expects to see.
Abbot had a different take and the engineer said he's never set a correction factor that high before.
He thought simply:
60 teeth x 607 tire revs per mile = 36420 pulses per mile.
36420 / 8000= 4.55 correction factor.
Anybody wanna play with their calculators and help a brother out?
My MG conversion is in the very last final phase and I still have one big dark cloud left. VSS. Here's the quick story of how I got in this mess.
I pulled out my 2WD E4OD from the van and replaced it with an E4OD out of an Expedition 4WD. This Expedition popped up on CL for a part out and $300 for a complete tranny was a hell of a lot cheaper than rebuilding the entire transmission to convert my 2WD to 4WD. I got to drive the Expedition before we tore it out and the tranny was great. I slapped it in my van and I ran into a problem. There was no connector on the tail housing for the VSS! Turns out the Expeditions pull VSS from the T-case UNLIKE the truck E4OD. It appears to be the only difference between them.
Here is how we are planning to solve this and I would like validation from the community we are headed down the right path and hopefully good input on figuring out the math. We plan to splice into the ABS signal wires coming from the rear differential of the Sterling 10.5 and run the wires through the AB001 signal converter I got from Ujoint to the van VSS plug. We need to come up with the proper factor to divide the signal from the rear diff by in order to show the PCM what it expects to see for how fast the van is actually moving.
Known information:
Ford PCM expects to see 8000 pulses per mile. This according to MG and I am inclined to believe he is correct.
Wrangler Duratrac 315/70-17 tires turn 607 revs per mile per Goodyear specs.
Rear axle ratio is 4.30.
Sterling 10.5 has 60 tone ring teeth.
Questions
1. Is the tone ring attached to the ring gear? If so, where does the 4.30 ratio figure into the equation?
2. Does the ring gear turn once per tire revolution? Driveshaft turn 4.3 times per one ring gear revolution?
MG figured it this way.
607 tire revs x 4.3 driveshaft revs per tire rev = 2610.10 driveshaft revs per mile.
4.3 x 60 pulses per tire rev= 258 pulses per driveshaft rev.
2610.10 driveshaft revs per mile x 258 pulses per driveshaft rev = 673406 pulses per mile.
673,405 / 8000 = 84.
We need to divide the ABS signal by 84 to show the PCM what it expects to see.
Abbot had a different take and the engineer said he's never set a correction factor that high before.
He thought simply:
60 teeth x 607 tire revs per mile = 36420 pulses per mile.
36420 / 8000= 4.55 correction factor.
Anybody wanna play with their calculators and help a brother out?