G35 Auto Transmission: Your Comprehensive Guide to a 6-Speed Manual Swap

The Infiniti G35 is renowned for its sporty handling and powerful engine. While the automatic transmission offers a comfortable driving experience, many enthusiasts crave the engagement and control of a manual gearbox. This guide provides a comprehensive overview of the process involved in swapping a G35’s automatic transmission with a 6-speed manual. This is an ongoing project, and will be updated as more information becomes available. Proceed at your own risk! Neither this website nor its authors are responsible for any damage to your vehicle.

Essential Parts for Your G35 Manual Swap

Before embarking on this project, ensure you have gathered all the necessary components. This comprehensive list covers everything from hydraulics to electronics:

Hydraulic System:

• Clutch Pedal: OEM or compatible aftermarket
• Clutch Master Cylinder: OEM or OE replacement
• Clutch Piping: OEM or aftermarket replacement (direct bolt-on to the slave cylinder)
• Clutch Line: OEM or aftermarket replacement
• Clutch Slave Cylinder: OEM or OE replacement

Drivetrain Components:

• 6-Speed Manual Transmission (6MT) Clutch Kit: OEM or aftermarket performance
  • Pressure Plate
  • Pressure Plate Bolts
  • Clutch Disk
  • Throwout Bearing
  • Pilot Bushing
  • Alignment Tool
• 6MT Flywheel: OEM or aftermarket performance
• 6MT Flywheel Bolts: OEM
• 6MT Transmission: OEM
• 6MT Shifter: OEM or aftermarket performance
• 6MT Rubber Grommet with Bracket: OEM from any manual transmission Nissan
• 6MT Driveline: OEM or aftermarket performance
• Differential: OEM 6MT or 5AT (5AT works with longer gears)

Interior Modifications:

• 6MT Brake Pedal: OEM or modified 5AT pedal
• 6MT Center Console: OEM
• 6MT Shifter Trim: OEM
• 6MT E-Brake Setup: OEM hydraulic with optional line lock
• 6MT Shift ****: OEM or aftermarket performance

Electronics:

• ECU: OEM 6MT, reflashed 5AT, or tuned 5AT
• EFI Harness: OEM 6MT or modified 5AT
• Hazard Light Switch (2003-2004 G35): OEM

Frequently Asked Questions about the G35 Transmission Swap

Q: Which parts are non-essential for a functional swap?

A: The following components are not strictly required for the car to run and drive:

• 6MT EFI Harness: The 5AT harness can be modified.
• 6MT ECU: The 5AT ECU functions adequately with a reflash or tuning.
• 6MT E-brake: Not mandatory.
• 6MT Differential: The 5AT differential functions well, albeit with longer gearing.
• 6MT Gauge Cluster: The 5AT cluster works; some warning lights might illuminate.

Q: What’s the difficulty level of this swap?

A: If you possess the skills to replace a clutch, you should be capable of undertaking this swap.

Q: Does anything require custom fabrication?

A: Only the clutch pedal installation and creating the shifter opening necessitate custom work. Everything else is a direct bolt-in.

Q: What’s the estimated cost?

A: The cost fluctuates based on whether you utilize new or used parts. Sourcing used components can significantly reduce expenses, with some swaps completed for as little as $700 (assuming a free transmission and interior parts).

Wiring Modifications for Your G35 Manual Swap

This swap requires minimal wiring modifications, primarily focusing on the starting system. Reverse lights and the neutral position switch are plug-and-play with the 6MT harness. If you are using the 5AT harness, there is some additional wiring required.

Starting System: The 5AT harness lacks a clutch interlock switch. You have two options:

• Option 1 (Bypass): Connect any switched 12V+ source directly to terminal 53 (grey/red wire) on the IPDM. This allows starting without depressing the clutch.
• Option 2 (OEM Functionality): Utilize the interlock switch from a used clutch pedal. Wire switched 12V+ to the switch, then connect the switch output to terminal 53. This restores the factory clutch-start safety feature.

Neutral Position Switch: This switch governs cruise control. It’s unnecessary if cruise control is disabled or an aftermarket steering wheel is installed. If you want to retain cruise control, wire ECU pin 102 (green/orange) to either spade on the neutral position sensor, then ground the other spade to the chassis.

Transmission Removal Procedure

1. Secure the vehicle on jack stands or a lift. Maximize ground clearance.

2. Remove catalytic converters, Y-pipe, and O2 sensors.

3. Drain the oil from the oil pan.

4. Detach the driveshaft from the differential and remove the carrier bearing. Slide the driveshaft out.

5. Unbolt the transmission mount, allowing the transmission to rest on the crossmember.

6. Disconnect all sensors, gear selector, transmission cooler lines, and the transmission fluid fill/drain plug.

7. Remove all bellhousing bolts. Disconnect and set aside the starter. Unbolt the transmission from the chassis by removing the four crossmember bolts.

8. Carefully extract the transmission, anticipating residual fluid spillage from the torque converter. Have a large drain pan ready.

9. Remove the brace connected to the lower control arm.

10. Access and remove the torque converter using a wrench. Once the torque converter is out, remove the flywheel.

Interior Disassembly: Center Console

1. Shift into neutral and remove the automatic shift ****.

2. Detach the shifter bezel by carefully prying it loose. Disconnect the seat warmers, ashtray lights, and hazard switch.

3. Remove the center console by unscrewing the four retaining screws (two beneath the radio, two on the sides).

4. Disconnect the parking cable that releases the ignition key.

5. Unbolt (four 10mm bolts) and disconnect the automatic shifter assembly.

6. You will be left with the shifter trim. Pry it off with a flathead screwdriver.

Interior Disassembly: Seat, Clutch Pedal, and E-brake

1. Remove the driver’s seat by unbolting the four retaining bolts and disconnecting the electrical connectors underneath.

2. Remove the kick panel, weather stripping, and lower dash cover. Disconnect the interior temperature sensor, trunk switch, dimmer switch, VDC switch, and hood release.

3. Unbolt and remove the e-brake assembly (four bolts). Disconnect the e-brake cable under the dash.

4. Remove the VDC/ABS/TCS module (four bolts) and unplug its connector. Remember to reconnect this later.

5. Remove or modify the brake pedal. If reusing, cut the pedal in half to accommodate the clutch pedal.

6. Cut the carpet and insulation to expose the e-brake bracket. Use a spot weld drill bit to remove the bracket.