Installation on Chrysler A518/46RH and Chrysler A618/47RH
Installing the 3rd Gear Pressure Switch
Locate the front servo test port on the right side of the transmission, immediately behind the bellhousing, but ahead of the pressure test port.
The test port is usually capped off with a 1/8" NPT plug. clean the area around the plug and remove it using an appropriately-sized socket or wrench:
Thread the switch into the port. Tighten the switch until it is finger-tight, then use a wrench to tighten it another 1.5 to 3 turns, depending on feel. Do not use pipe sealant on this switch as it must make electrical contact with the body of the transmission.
Do not overtighten! The transmission case is made of aluminum and the pressure switch is made of brass. Both are soft metals and will strip easily.
The final installation should look like this:
![](../__attachments/2141716891/A518.jpg?inst-v=1fa9c909-936f-4e45-ad37-149512e12010)
Installing the Speed Sensor
As installed in the vehicle, the transmission should have speedometer cable attached to the speedometer drive output of the tailhousing.
Clean the area around the end of the cable, and unscrew the cable nut from the drive output.
Remove the cable and set it aside. The drive output should look like this:
Locate the speed sensor you assembled earlier:
Screw the speed sensor into the speedometer drive on the tailhousing, being sure to engage the short cable inside the drive.
Snug the nut securely with a wrench ensuring that the speed sensor wires point toward the front of the vehicle.
Reattach the speedometer cable to the output of the speed sensor.
Installing the Wiring Harness
Earlier, you pushed the wiring harness through the firewall and installed the grommet.
From the underside of the vehicle, locate the wire harness and begin routing it toward the right rear side of the transmission.
Locate the transmission socket, shown below:
Connect the harness plug into the socket, and then connect the speed sensor.
Use one of the provided cable ties to fasten the harness to the bellhousing as shown:
Then route the wires of the harness over the top of the tailhousing toward the front left side...
and connect the third gear pressure switch.
Use other cable ties as needed to fasten the wiring harness clear of any rotating parts, linkages, and the exhaust system.
Install / Connect the Throttle Position Sensor
If you purchased a throttle position sensor for your kit, you will need to install it now and connect to to the TPS wires on the wiring loom.
If you are using an existing throttle position sensor, an adapter should be provided to connect it.