1999 5.0 VSS Question | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

1999 5.0 VSS Question


New Member
January 2, 2019
Reaction score
City, State
San Jose, Ca
Year, Model & Trim Level
99 Exploer XLT 5.0
I have a 1999 xlt 5.0 explorer that I am building into a rock crawler. My plans are:

2006 Super Duty D60 5.38
3link w/ coilovers

14b or Sterling 10.5 with 5.38
63" Chevy's

Atlas 3.8 or 4.3

39.5 TSL

The question I am having trouble finding an answer for is how the VSS will react in low range. I know if i use the sterling it has the vss on axle, but i've read in low range the computer will compare the speed to the Output shaft sensor on the 4r70w, and it won't shift correctly.

Am I overthinking this or how can the low range shift issure be handled?

Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!

Why would there be a problem with low range?

The 99 Explorer gets its VSS signal from the rear axle speed sensor, the signal is sent through a module and then to the PCM
You are installing a sterling 10.25 in the rear that still has the same VSS sensor......so the truck has no idea anything has changed? Low gear is just a gear, you are still moving at either 5 mph or 30, does that make sense?
I am not sure why the shifting would be different? I have seen 5.0 rangers with 5.13 axle gears and 37" tires, no shifting issues. I have never run into a low range gear shifting issue...
Since you are putting in a Ford vss that is identical to the VSS that was in there I do not think you will have any issues, or I could say I cannot think of any reason this wont work.

I agree that running the sterling 10.5 with the axle mounted vss would be the same as stock, but in stock form the awd tcase had no gear reduction. So the outputs from the OSS and vss would always have values proportional to the gear ratio. And with a tcase in low between the two the values would be off by a larger factor. The guy answering the phone a baumann thought it would be a problem.

I have setup trucks with 1354 t case, 4406 t case, np205 t case and I know of several trucks with doubler t case v(1356/205) or ATLAS 3:1 even 4:1 cases behind the 5.0 and 4r70w, never had a vss issue

I do not think you are going to have a problem but Baumman (US shift?) knows their stuff so........

410 has seen and done it, I have no doubts you will not have any issues. All the manual T case conversion posts, and write ups here, I've never heard anyone complain about giving up a properly shifting transmission when in low range.

Awesome, thank you both for the info. It's very much appreciated.