The 12-Step Program

Yes, you can install an overdrive transmission in your street rod, and it is a relatively simple process if you take it one step at a time. After locating a good or rebuilt transmission, here are the 12 basic steps toward your new transmission. Of course some things may vary a bit from one car to the next, but this is a general outline of the installation process as outlined by our friends at TCI Automotive. When you receive your EZ-TCU it will come with much more detailed instructions.

1. Connect the trans and output shaft speed connectors from the wiring harness to the transmission. Route the rest of the harness into the engine compartment.

2. Determine the appropriate method for getting an rpm signal into the TCU. Install the rpm module if needed. Connect the wiring harness to the rpm signal source.

3. Connect the wiring harness to a TPS signal source.

4. If a mechanical speedometer will be used, install the optional TCI Automotive SCU and connect the wiring harness to it.

5. Find a suitable location and mount the TCU. Make sure the wiring harness will reach the mounting location.

6. Connect the Battery POS and Battery NEG wires directly to the battery. These must be run independently to the battery. Do not splice other power or ground wires into these wires. Extend the wires if necessary to reach the battery. Use automotive grade 16-gauge (or larger) wire.

7. Connect the 12V switched wire to a switched ignition source (hot in on/run and crank). Do not connect to the positive side of an ignition coil.

8. If manual shifting will be used, route the manual shifting connector into the cockpit and wire in an enable switch and a pair of buttons for upshift and downshift.

9. To use the Forced TCC Lockup feature, route the TCC apply wire into the cockpit and connect it to a switch or button.

10. To access performance mode, route the economy/performance wire into the cockpit and connect it to a switch.

11. If an electronic speedometer will be used, route the speedometer output wire into the cockpit and connect it to the speedometer.

12. Connect the wiring harness to the TCU.

4L60E ID Guide

Late 4L60E 1997-2006: The most notable difference between the 4L60E and the 700-R4 and early 4L60 is the six-bolt tail housing pattern on the new transmission and the two-piece bellhousing.

GM Designations:

4lL60E: M30

4L65E: M32

4L70E: M70

TCI Automotive
151 Industrial Drive
MS  38603