GLHS

I need to get a spedometer drive adapter made and need to know the ratio on the little box conected to the transfer case. Mine was lost.

Thanks,
Kurt

blue92

In order to figure mine out I installed my vehicle speed sensor directly to the output from the transfer case. I then drove it with my gps unit and calculated the difference between my speedo and gps. I then found some speedometer ratio adapter on eBay and found one very close. Hope this helps.

Bigone721

Your just gonna have to do it like blue92 said, because it will depend on what size tires you have and not just the rear gear ratio. There are also many different sizes of driven gears in the transfer case so you really just need to use a gps.

Chrisreyn

Which peice exactly are you needing?
the gear reducer( the 90* box) isnt what determines the ratio, the pinion drive gear inside the tranny/T-case does..
this has info you might find helpfull:
How the speedometer drive works:
https://www.dieseltruckresource.com/....html?t=198123

GLHS

I need the gear ratio reducer ( the 90* box).
I know I can hook up the VSS straight to the transfer case; was hoping someone had the part # or could take a quick look at the box to find the ratio. Who knows with a part number might get lucky and find a dealer who still has one on the shelf.
Height wise, my 265/75/16s are the same as the original 235/85/16 tires.

Fred Swanson

GLHS, I might have a few of those around, let me look.