How to Convert Auto to Manual Transmissionby Don Bowman
Converting a manual transmission to an automatic is much simpler than converting an automatic to manual. This is a project that requires many parts and a strong mechanical aptitude. The brake pedal for the automatic will need to be replaced with a complete manual brake and clutch installation. On a rear-drive vehicle, the drive shaft may also need to be replaced. A separate bell housing, clutch mechanism and hydraulic or manual clutch mechanism will be needed and, finally, a shifter and linkage.
Remove the existing gear shift linkage, if it is a column shift, or the shifter, if it is floor-mounted. If it is a column mount, use a small hammer and tap out the roll pin holding the gear shift lever. Remove the shift cable from the lever at the base of the column and pull it through the firewall. If it is a floor shift, it will be necessary to remove the center console and take the shifter loose from the floor. Simply unscrew the bolts holding the console and the floor shifter to the floor.
Unbolt the brake pedal linkage from under the dash. Disconnect the electrical connector to the brake light switch. Bolt in the new clutch and brake pedal assembly under the dash. Bolt on the new brake light switch and connect the electrical connector.
Raise and support the vehicle on four jack stands. Remove the gear shift cable or linkage from the transmission by removing the nut on the linkage and pulling the gear shift lever off. Save the gear shift lever for later installation.
Disconnect the torque converter by removing the inspection cover with a wrench and removing the bolts in the torque converter using a 3/8-inch drive ratchet and socket. Remove all electrical connectors from the transmission. Remove the bolts in the drive shaft yoke using a wrench. Remove the drive shaft.
Place the floor jack under the transmission pan and remove the bolts in the cross member and transmission mount using the ratchet and socket. Lift the transmission and remove the crossmember. Lower the transmission and remove the transmission cooler lines with a wrench.
Remove the bolts in the bellhousing with a ratchet and socket and remove the transmission. Remove the flexplate using the ratchet and a socket.
Install the new flywheel and tighten the bolts. Install the new clutch kit using the alignment tool that comes with the kit. Tighten the bolts securely. Install a new throwout bearing in the new bell housing and bolt up the new bell housing.
Bolt the new manual transmission to the bellhousing by inserting the bolts and tightening them with a ratchet and socket. Plug in all electrical connectors.
Install the transmission mount and tighten the bolts with the ratchet and socket. Place the floor jack under the transmission and raise it to install the crossmember. Lower the transmission onto the crossmember and insert the bolts and tighten. Install the driveshaft and bolts and tighten with a wrench.
Pass the linkage or cable through the firewall and attach it to the clutch pedal. If it is a hydraulic clutch, attach the master cylinder to the clutch pedal and the firewall. Bolt the transmission-end of the linkage or cable to the clutch release rod on the transmission. If it is a hydraulic system, attach the slave cylinder to the transmission.
Install the shift lever on the transmission by putting the nut on the shaft end and tightening it with a wrench. With your hand, put the shift lever on the transmission in the neutral position. When it is in neutral the drive shaft can be turned by hand.
Remove the top cover plate on the transmission if it is a top loader. Bolt up the shift lever and cover. Cut a hole in the floor for the shifter, if it is a side mount shifter. Bring the shifter and stick the handle up through the floor and insert the bolts through the side of the shifter holding it to the transmission. Tighten the bolts with a ratchet and a socket. Bolt the linkage from the shifter to the shift levers on the transmission. Make sure the shift and the transmission shift levers are both in neutral.
- Don Bowman, A.S.E. Certified Mechanic
Things You'll Need
- Floor jack
- Jack stands
- Common screwdriver
- Phillips screwdriver
- Needle-nose pliers
- 3/8-inch drive ratchet
- 3/8-inch drive extension
- Set of 3/8-inch drive sockets
- Hole saw
- Set of drills
- Set of wrenches
- Drip pan
- Manual transmission
- Bell housing
- Drive shaft
- Crossmember for a manual transmission
- Pedal conversion kit from automatic to manual
- Linkage for clutch pedal or hydraulic system
- Gear shifter mechanism and linkage
Don Bowman has been writing for various websites and several online magazines since 2008. He has owned an auto service facility since 1982 and has over 45 years of technical experience as a master ASE tech. Bowman has a business degree from Pennsylvania State University and was an officer in the U.S. Army (aircraft maintenance officer, pilot, six Air Medal awards, two tours Vietnam).