Auto to Manual Transmission Conversion
The Datsun 240K sedan (2400 cc engine) has a similar gearbox to that in the Z. The only difference is in the ratios. A cheap way to convert to a manual is to use a scrapped 240K (they are very cheap). The only difference is the pedals and the piping. -Ed.
by Michael Fawke, member of the ACT Z club.
The ACT is the Australian Capital Territories. All amounts are in Australian dollars. This article remains the property of the author and may not be used for commercial purposes.
On the weekend of the 25 and 26 of September, I finally did the gearbox conversion I have been talking about doing since 1989. For those of you with automatic gearboxes, this article may be a help. I have probably missed out a few steps, but not the major ones. I did 95% of theis job myself- the only help required was when tightening up the flywheel boltrs. Before this job started, I had already had the pedals and the master cylinder fitted. Total cost was around $1000
not including the $225 I spent on a new trolley jack. The advantages are that the car warms up quickly (it doesn't have to heat 5 litres of oil), uses less petrol and goes a lot faster!
24/9: Preparation . . . . . . [ 1700 - 1745 hours ]
- The car was driven up on to ramps, then the rear of the car was lifted to the same height and placed on axle stands.
- Battery Removed
24/9: Disassembly . . . . . . [ 0930 - 1330 hours ]
- The transmission pan was removed and most of the fluid was drained, then the pan was reattached.
- The rear sway bar was unbolted and dropped down, then the tailshaft was unbolted and removed.
- The oil cooler lines were removed.
- The vacuum sense line was removed from the manifold.
- The inspection plate was removed from the manifold.
- The starter motor was removed.
- The bolts holding the torque converter to the flex plate were removed.
- The inhibitor switch and gearbox selector lever removed.
- Oil filler tube removed.
- Speedo cable removed.
- Engine fan removed ( so it doesn't hit the radiator when the gearbox is lowered )
- Exhaust system removed and extractors unbolted from the engine.
- Jack placed under the gearbox and the rear crossmember is removed.
- Another jack placed under the rear of the engine. The bolts holding the engine to the gearbox are removed.
- Transmission pulled back and lowered down ( where it promptly fell off the jack ).
- Bolt placed in the back of the engine and a screwdriver is used to hold the flex plate whilst the bolts are removed.
- Flex plate removed and the cap on the rear of the crankshaft is removed.
25/9: Assembly . . . . . . [ 1430 - 1730 hours ]
- Pilot bushing driven into rear of crank shaft.
- New backing plate placed on rear of engine.
- Fly wheel bolted to rear of crank shaft.
- Clutch pressure plate and driven plate bolted to flywheel.
- New gearbox prepared with clutch withdrawal arm and thrust bearing.
- Gearbox placed under car, put on jack, then brought into alignment with rear of engine.
At this point it was discovered that the bolts to hold the gearbox to the engine were too short. Bill Cowden was nice enough to loan me some bolts which were used to hold it together overnight. I'll return them Bill - I really will!
26/9: . . . . . . . . . . . [ 0800 - 0900 hours ]
- Hole in floor enlarged by one inch at front because the gear shifter was in the wrong place.
- Rear of gearbox raised and rear cross member bolted in place.
- Extractors bolted back onto engine.
26/9: . . . . . . . . . . . [ 1330 - 1630 hours ]
- Tailshaft bolted back in. Swaybar reattached.
- Starter motor bolted back on.
- New bolts ( hi tensile 60 mm bolts 10 x 1.5 [Please confirm this detail -Ed] ) to hold gearbox to engine fitted.
- Exhaust system connected.
- Fan replaced on engine.
- Gearstick fitted to gearbox.
- Speedo drive swapped from auto to manual box and cable fitted.
It was then discovered that the clutch line that had been made up the day before at a local workshop was not flared correctly. A trip was made to a local `Super Mechanic' (who worked on Nissan factory Z rally cars !!) who has a flaring tool.
26/9: . . . . . . . . . . . [ 1930 - 2105 hours ]
- Gearbox fitted with oil.
- Clutch slave cylinder bolted in place.
- Clutch line attached.
- Clutch bled.
- Hole in inlet manifold plugged.
- Inhibitor switch wiring bypassed. Reversing light connected.
- Car lowered off axle stands.
- Battery refitted.
- Car started and backed off ramps. Job finished, 9.05 PM.
The only finishing details which wre done at a later date were the gearstick boot and knob and the bellhousing dust cover.