In 1988 (I believe), The Dodge truck family (pickups, vans and Dakotas) had a new sensor added for the fuel injection system – the VSS (Vehicle Speed Sensor). What Dodge did was add a screw-on sensor between the speedometer cable and metal speedometer gear housing. The cable nor the housing was changed and part is fairly easy to change.
Matter of fact, if you needed to
add a vehicle speed sensor (VSS) to your Mopar, this is an easy way to do so (for fuel injection, or whatever).
The VSS sensor part number is 5233152.
There is another location to place an “in-line” VSS and that is at the cruise control servo. That part number is 4439097. It matters not what direction the VSS spins (so it can attach to either cable). There are also a few different versions/styles of this one.
In, 1990 (I believe), Dodge did away with the speedometer cable altogether – going with an electric speedometer head. The electric speedometer head (in trucks) was not the most reliable part Dodge has used, before. The VSS sensor looks close to the same sensor (above), for it still screws to outside of the metal speedometer gear housing – but sensor does
not have a provision for speedometer cable to attach to it, any more.
Again, the metal/plastic speedometer gears are still the same Chrysler has used sense 1966.
In 1993, the system changed. The speedometer housing hole is still in transmission and still being used, but the sensor changed drastically and Dodge started to use a short (metal) shaft version of the speedometer gear.
The short shaft gears are found in most (older) transfer cases (4x4’s) and is commonly used in Jeeps (as well as the ’93 and up truck speedometer gears).
The Jeep community has made aftermarket short shaft gears – just the same way that the muscle car community has made the long shaft gears aftermarket.
The long shaft housing is still a far more popular part to locate.
The plastic gears/plastic housing gears has zip, zero, nada support so our gears are very hard to find – especially for those who do don’t use the more popular gear sets (aka: the 2.2,
2.4,
2.6 & 2.8 differential gear ratios.
Red means harder to find).
Matter of fact, I just now performed a quick search on eBay for a plastic speedometer gear and only found 1 (one) plastic gear vs. 1,040 older style steel/plastic gears.
Examples of long shaft gear, a short shaft gear (Jeep) and a typical FMJ gear (in order):
Note: I wish I had that collection! All pictures stolen from eBay.
VSS pictures (for reference)
I couldn't find a picture of the '93 design - but have one in my garage, somewhere. It has a plastic housing (like the older geared housings), has same electrical connector but also has speedometer gear on other end.
BudW