Specifications

Computer Controlled GM engine & drivetrain in
a GM 4WD vehicle (Atlas T/C install)
Transfer case tailhousing VSS
Atlas transfer case Kit # AVT32L provide a VSS
tailhousing with the provision for a low-range
switch. (See the Atlas manual for more info.). If
the Atlas T/C is not being used, then a GM trans-
fer case that came behind the donor engine
can be used. All other transfer cases will re-
quire a custom fabricated VSS.
Computer Controlled GM engine
with non computer controlled auto-
matic or manual transmission.
VSS is needed, but location is not
critical
The VSS can be in the transmission
or transfer case and still function
properly. We offer a reluctor kit that
fits on all of our tailhousing kits for
the Jeeps. This kit is an external
mounted unit that provides a Tru 40
Pulse required for the computer sys-
tem. The reluctor ring gets mounted
to the transfer case yoke. The kit is
offered in several yoke styles except
a flange yoke. Our Tru-Pulse kit fits
the Dana 20, 300, NP, and Atlas
transfer cases.
P/N 50-5040 is a 1310 non CV.
P/N 50-5041 is a 1310 CV.
P/N 50-5042 is a 1350 non CV.
P/N 50-5043 is a 1410 non CV.
Computer Controlled GM engine with
a computer controlled automatic
transmission.
Transmission Output VSS
Transmission:
700R/4L60 -
Jeeps 50-0402, 50-0403, 50-0404
50-9103, 50-9104
Early 4L60E - All vehicles can use
P/N 716073. You can also use the
adapters listed under the 700R/
4L60.
Late 4L60E - See the adapters
listed under 4L60E in your vehicles
specific year.
4L80E - Most early transmissions
have a internal tone ring for VSS.
The 1997 & later 4WD transmis-
sion did not. If you are using a 1997
& later transmission, you need to
install a tone ring.
On later model transmissions
coupled to an Atlas, we offer kit 50-
6409 which will provide a rear re-
luctor ring.
VEHICLE SPEED SENSOR INFORMATION
Computer Controlled engines and/or transmissions require a Vehicle Speed Sensor (VSS). Although there are a couple of
different styles of sensors, they all perform the same type of purpose - to tell the computer (or PCM) how fast the vehicle is traveling.
Using this data, the computer can determine how to adjust for freeway driving, fuel economy, transmission shift points (automatic
only), and how to get the best performance at any given moment. Power and fuel economy will be lost if the VSS is not functioning
properly. A few different styles of VSS are shown below.
Application
1986-1992 GM TBI engines
1985-1989 GM TPI engines
GM trucks (1993-current)
Jeep (1987-current)
Signal type
Square wave signal - two wire
sensor “Pulse Generation”
Sine wave signal - two wire
sensor “Voltage Generation”
Square wave signal - three wire
sensor “Pulse Generation”
Pulse count per
driveshaft revolution
2
40
3
Mechanical Speedo
driven signal available
Yes
No
See voltage generation chart
Yes
Late model GM Engine Voltage generation
GM 40 pulse Vehicle Speed Sensor - proper location flowchart:
P/N 716073 fits in the main case of a 4L60E
transmission and provides a voltage signal.
18
vss & voltage charts
As can be seen above, some Vehicle Speed Sensor signals can be created from a standard
mechanically driven speedometer. These drivetrains are much easier for swapping because it
allows the use of almost any transmission or transfer case combination.
For the 40 pulse GM VSS, there are much fewer options. Please refer to the flowchart below to
determine the correct location for the GM 40 pulse VSS in your application.
We do not offer any type of mechanical speedometer driven VSS units; however, these type of units
(pulse generation / square wave) are available from most companies that supply engine wiring
harnesses or custom speedometer shops such as Nevada Speedometer. Tel# [phone].