Auto to Manual in an OBDII S14 - With Pictures
First off, the big question: This swap cost about $400 - 500 for everything (parts, oil, lube, special tools, wire) if you do it yourself
In this writeup, two different cars were having the conversion done simultaneously. One is Matt’s ’98 starfire blue S14, the other is my ’97 cobalt green S14. The procedure was basically the same for both cars, and some pictures may jump from one car to the other. The procedure is the same for OBDI cars except OBDI cars to not require the a Crank Angle Sensor. The parts necessary for the swaps were obtained from 2 separate OBDII ’96 S14s. OBDI transmissions could have been used, but a mount would have to be drilled for the CAS, and we didn’t want to worry about that. The conversions were carried out in my 2 ½ car garage using jackstands and basic tools. I will try to provide as many pictures as possible. This writeup will be broken down into the following categories:
Parts Needed
Tools Needed
Procedure – Auto Removal
Procedure – Manual Install
Wiring
Results
ECU Swapping
WARNING:
Before you start I suggest you read this entire writeup, and search for others - you will want all the info you can get. Also, plan on this taking longer than you think - some bolts are extremly hard to get to or break loose - and the transmissions are heavy and hard to stab in. You will need patience. Do not sacrifice safety for getting it done quickly. Although a 240sx only weighs 2800 lbs, it only takes 15 lbs of pressure applied correctly to break the human skull.
PARTS NEEDED:
5 speed OBDII transmission
5 speed Driveshaft front and rear sections (this may differ if you have ABS/LSD)
Flywheel (new or resurfaced)
M/T flywheel bolts (A/T bolts are too short)
Clutch Kit (Clutch, Throwout bearing, Pressure Plate, alignment tool – check Autozone for a OEM Duralast one)
Shifter assembly (plate, lower rubber boot, upper leather boot, finisher plate)
5 speed Crossmember
Clutch Master cylinder
Clutch Slave cylinder
Clutch hardlines
Clutch rubber line and dampener line (which you may want to remove anyways)
Clutch pedal assembly
5 Speed Brake pedal assembly or a cut brake pedal (automatic pedal is much larger)
Bellhousing bolts for a 5 speed bellhousing (some of the A/T bolts can be reused)
TOOLS NEEDED:
(Metric)
Wrench Set (ratcheting wrenches come in handy, so do abstruction wrenches)
Socket Set (with plenty of extensions)
Breaker Bars
Torque Wrench
Vice Grips
Jackstands
Floor Jacks
Scissor Jacks (to help support stuff under the car – you don’t have to fit the big bar under also)
Pilot Bearing puller (can be rented at Autozone)
Slide Hammer for Pilot Bearing Puller (can be rented at Autozone)
Loctite
RTV Gasket Maker
Propane Torch to break loose flywheel bolts (can be bought at Autozone)
Wire Strippers
Wire Cutters
Wire Connectors
16 guage wire (A few different colors)
Wire Connectors
A few friends (Asian ones with small fingers help)
Factory Service Manual (can be d/led on some sites)
PB Blaster
Gear Oil 75W90
Brake fluid or clutch fluid (same thing)
Dremel with cutting bits
Power drill with metal cutting bits and circle cutting bits
Carb Cleaner (to clean off flywheel)
Procedure – Auto Removal
1. Put the car up on jackstands as high as you can get it (you will need to slide the tranny out the bottom), make sure it is not going anywhere – it will be shaken a bit. Also we found it best to take off the front wheels to give you a little more room to work in. Drain your transmission fluid from the draining bolt.
2. Remove the finisher plate from your center console. Remove the console from the car – only a few bolts and it will lift off.
3. Remove the 2 harnesses that come out of your carpet and connect to the a/t shifter.
4. Remove the Cotter pin holding the A/T shifter to the A/T tranny
5. Remove the shifter and all the stuff that comes with it. You will now see the ground through your center console.
5 1/2. remove the shifter cable that goes to the ignition, it controls the key release
6. Next, take out the driveshaft. On the differential side there will be 4 bolts that hold the driveshaft to the diff. Remove these bolts, you will want your parking brake on to keep the driveshaft from spinning. To get to the upper bolts, take off your parking brake and your driveshaft will spin, then reapply the parking brake (not too hard there guys). Let the back side of the driveshaft lay on the floor. Also remove the small d-shaft suport a thick wire X-member that keeps the driveshaft from whipping around if it breaks. Next, remove the bracket that holds the middle of the driveshaft up, and slide out your driveshaft.
7. Next, remove the dust plates from the transmission bellhousing, they are at the very front of the transmission.
8. There are some A/T cooling hardlines that run all over the automatic transmission, and two that run to the radiator. Disconnect these hardlines and pull them out. Don’t be afraid to bend them – you won’t ever use them again. Get them out of your engine bay.
9. Disconnect all the sensors you can from you transmission, and the back O2 sensor on your exhaust. Two of the sensors can be cut.
10. Now for one of the time consuming parts (this took us most of a day). You will have to weave your hands in everywhere to find and remove the bellhousing bolts holding the transmission bellhousing onto your engine. We used a ratcheting wrench on the top bolts, with a breaker bar and a jack running from underneath the car to the wrench ontop of the engine. For some of the other bolts we used a socket (with swivels), and for still other bolts we used obstruction wrenches. One of the top ones has a recirculation pipe bracket attached to it, the pipe runs down to the transmission – disconnect it and remove the bolt. Two of the bellhousing bolts run through the starter, disconnect the starter before you take out these bolts then remove the starter. We found that the best way to access the two top bellhousing bolts was thru the passenger side of the engine bay, behind the engine block - we found it necessary to move some lines and disconnect a heater hose.
11. Next, remove the bolts holding the tranny to the crossmember, then jack up the back of the tranny and remove off the crossmember. At the same time, get as many jacks as you can under the tranny – in a few steps it will come off. Also, there is an exhaust bracket on the tranny you must remove.
12. Where you took the dust plates off of the bellhousing earlier, you should be able to look back into the transmission and see some bolts holding the torque converter onto the flywheel – undo these 4 bolts. To get to the top ones, get a 27mm socket and turn the crank pully.
Note: the flywheel gets hard to turn when the engine starts a compression stroke.
13. After the torque converter is unbolted, the transmission will come loose (if not, you can kick it from the front some) – it will pop off and weighs about 250 – 300 lbs. ( a good bit more than the 5 speed – which means that this is a weight reduction!) Get some of your friends to help with this part. Slowly lower the transmission part way down and disconnect any of the wiring that you did not get before. Then slowly lower the tranny the rest of the way – you don’t want it to fall to one side and knock out a jackstand
14. This next step is very frustrating. The automatic flywheel is held on by 6 bolts torqued down to about 120 ft/lbs, and your flywheel will try to turn when you try to break these bolts. Brace your flywheel from moving as best you can. We actually wedged in a jack bar to keep the flywheel from spinning, and put 2 sockets and breaker bars on the flywheel (one braced against the ground tightening to keep the flywheel from spinning, and another to break the flywheel bolts). If you have a propane torch, heat these mofo-bolts up and that should help you break them loose some more. If you (unlike us) have an impact wrench this may come in handy.
Linear Mode
