BW 1350 Speedometer regearing

[RonSerling]

I have an issue with my 93 Ranger. It is a 4.0 with a M5OD and a BW 1350 transfer case. So I regeared the axles with 4.56 gears and I knew this was going to throw my speedometer into chaos. So I disconnected the speed sensor on the speedo cable so it would go 75 mph without shutting the engine down, the speedometer gets buried at about 65 mph and the speed sensor shuts the truck off. With the speed sensor disconnected I get a error code, 452, and the check engine light stays on !!! My question is does anyone know how to regear the BW 1350 so my speedometer will read correctly and also where or who would have the parts to do it. I am pretty sure it is an easy fix but I have been researching it for a couple days and have gotten no answers to the problem. Any information would be appreciated !! Thanks

 

[RonD]

Go here: https://www.tciauto.com/speedometer-gear-calculator

You have a 7 tooth worm gear, that's the DRIVE gear number you need
4.56 ratio
And measure tire diameter if you don't know it

Then "calculate", that will give you the DRIVEN gear tooth count you need to change to
It will be a decimal place number like 20.4, so use 20 tooth, if 20.7 then use 21 tooth

Just remove the 1 bolt holding the VSS/gear drive unit and pull it out, change gears and put it back in

Unit looks like this when removed: https://www.therangerstation.com/tech_library/images/speed/vss_withgear.JPG

 

[duffy]

I'm assuming that you have a mechanical speedometer here. On my 89' Bronco II with a BW1350 the speedometer is mechanically driven by a gear and cable set up off the rear of the Xfer case (combines with the VSS). There are different gears to correct the speedometer......if you are reading "fast" then you will need a higher number of teeth gear than what you currently have....they are color coded for the tooth number. First you need to determine what color/number of tooth gear you have.....changing one tooth # will change the speedometer about 3 mph. The available gears are some what limited. Google is your friend when calculating this and finding the available gears.

 

[4x4junkie]

A 1993 should have a BW1354 transfer case... Did you swap in a 1350?

1350s have 6-tooth (red) drive gears (all the ones I've seen anyway), 1354s have 7-tooth (white) gears.