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Tranny Swaps
Swapping an automatic transmission for a 5 speed.
If you find yourself craving a little more performance from your automatic transmission equipped chevette, you might be considering doing a transmission swap. Many people find that they don't know exactly what they will need to perform the swap, so I have taken the time to put together a basic procedure for changing your chevette from an automatic to a 5 speed.
First of all, I would like to add that this is just a guideline for you to follow, I will not be held responsible if you mess up your car trying to perform the swap. DO NOT attempt the swap unless you feel that you have the basic mechanical knowledge to complete the swap and do everything properly.
The first thing you will need to do is get all your parts together. It may be handy if you have a 5 speed donor car to get all of the parts from.
Parts Required:
-5 speed chevette transmission
-Shifter Assembly for 5 speed transmission
-5 speed Transmission Crossmember
-Driveshaft *
-Flywheel and Clutch Assembly**
-Throwout bearing**
-Pilot bearing**
-Clutch Cable
-Plastic Clutch Cable Adjusting sleeve / bushing
-Clutch pedal assembly
-5W30 engine oil
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Tools Required
-Basic hand tools (Sockets, Wrenches, etc.)
-Clutch Alignment tool
-Dremel Tool or equivalent
-Hydraulic Jack
-4 Good Jack Stands
-Oil Drain pan (Preferably a big one)
-A pump of some kind to pump oil upwards into the transmission
-An Assistant is helpful
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* You will need to obtain a driveshaft from a 5 speed car with the same number of doors as your car. (ie. if your car is a 2 door, get a driveshaft from a 5 speed 2 door car)
** Now is a GOOD time to install a new clutch, throwout bearing, and pilot bearing!
Procedure
Removal
Here is the basic procedure for removing the automatic transmission.
1. From inside the car, put the transmission in any gear other than park, then remove the shifter knob and console. There is a cable that attaches to the shifter which runs to the steering column. Disconnect this cable from the shifter and either remove it completely (hard), cut the cable off so it's not sticking in the way (less hard), or just tuck it under the carpet (easy). This cable is for the shifter interlock, which is not used on the 5 speed. Now, once the cable is out of the way, unbolt the 4 bolts that hold the shifter to the floor of the car. Don't remove the shifter yet. Also, disconnect the wiring plug from the shifter.
2. Jack the car up as far as you can get it safely. Put it on the jackstands.
3. Crawl under the car and disconnect the shift rod at the transmission end.
4. Go back inside the car and pull the shifter off the floor. You should now have a square hole in your floor.
5. Get out your big oil drainpan and drain the automatic by unbolting the pan from the bottom of the transmission. Hopefully your drainpan will catch at least half of the fluid that pours out of the transmission. Get as much of the oil out as possible, and then put the oil pan back on.
6. Remove the driveshaft by undoing the 4 bolts at the rear end of the driveshaft. You will want to rotate the driveshaft so that two of the bolts are facing downwards, and then set the handbrake so that the driveshaft will not turn. Once two of the bolts are out, release the handbrake, rotate the driveshaft 180 degrees, re-set the handbrake and remove those bolts. Do not lose these bolts and the U shaped retainers. Pry the driveshaft forwards, off of the yoke. The driveshaft is under spring tension, so you will be pushing against the spring. Push the driveshaft forwards until it is out of the yoke, and then pull it down and away from the transmission.
7. Disconnect the speedometer cable from the transmission. Wiggle it out once the retainer is removed.
8. Remove the crossmember-to-transmission mount bolts. These are the two small bolts and one big bolt in the middle of the crossmember.
9. Remove your exhaust downpipe and catalytic convertor at this point. If your exhaust was installed correctly, you will need to unbolt an exhaust hanger from the transmission. Unbolt the downpipe from the manifold, and from the rear half of the exhaust, and take it out in one piece.
10. Place a jack under the transmission pan, jacking it up just enough to take the weight of the transmission off of the transmission crossmember.
11. Undo the 4 crossmember-to-floor bolts, and remove the crossmember.
12. Remove the dustcover from the bottom of the bellhousing.
13. Crank the engine over by hand (A Ratchet and socket on the crankshaft pulley will work) until you can see one of the 3 torque convertor bolts through where the dust cover was on the bottom of the bell housing.
14. Have your assistant jam a screwdriver or similar device in the flexplate ring gear while you remove the torque convertor-to flexplate bolt. There is a small hole in the bottom of the bellhousing with a plastic cover which pops out. Remove the plastic cover, and you have somewhere to jam your screwdriver so that the engine doesnt turn over.
15. Repeat steps 13-14 until you have removed all 3 torque convertor bolts.
16. Cut the transmission cooler lines that go to the radiator. You will not need these with the 5 speed. Also disconnect the wire plug from the transmission. There are only one or two wires in this plug.
17. Disconnect and remove the kickdown cable at the carburetor. Disconnect the vacuum line for the vacuum modulator on the transmission, and plug the line at the engine.
18. Either remove the transmission dipstick, or bend the dipstick down so that it will clear the firewall of the car.
19. Remove all of the bellhousing to engine bolts that you can from the bottom of the car. There are 8 bolts total, you should be able to remove 5 or 6 from under the car.
20. Remove the remaining bellhousing bolts from the top of the bellhousing from the top.
21. From under the car, lower the jack slightly and move the transmission to the rear. Don't put yourself in a position where the transmission could drop on you.
22. The transmission should now be clear of the car. If it's not, carefully give it a kick on the side so that it will seperate. Keep the bellhousing end higher than the rear to prevent the torque convertor from falling off.
23. Lower the jack all the way, and drag the transmission out. Watch for bellhousing to floor interference when you are dragging it.
The transmission should now be out of your car, ready for the next step: Converting everything over.
Converting everything over
1. First, make sure that you have allready done certain things mentioned in the above "Removal" section. This includes removing the transmission cooler lines, removing the wiring for the Lock up torque convertor, and plugging the vacuum line for the vacuum modulator.
2. Now, cut the hole for your shifter. You need to enlongate the hole towards the rear of the car about 1.5", and to the left about an inch. Alternatively, if you have cut out the floor part from a five speed car, just cut out the equivalent part from your car and weld in the new part. If you do weld in anything, be sure to properly prime, paint, and undercoat the welds or they will rust!
3. Remove the automatic transmission flexplate from the engine. There are six bolts that attach this to the rear of the crankshaft. The bolt heads are very shallow, so be careful that you dont strip the heads off of the bolts. Also, it is good practice to tighten and untighten any bolts on this in a criss cross pattern, like you would do with wheel nuts.
4. Now that the flexplate has been removed, install the pilot bearing into the hole in the end of the crankshaft. Make sure you clean out any gunk or dirt that might be in the hole. Be sure to install the pilot bearing in the right direction. Basically, the inside of one end will have a chamfer on the edge, while the other end just has a flat edge. The chamfered edge will face the rear of the car. Tap the pilot bearing into the crankshaft with a small socket on an extension.
5. Install the manual transmission flywheel to the crankshaft. Oh yeah, if you havent done it already, have the flywheel machined for the new clutch that you are putting on. Tighten the six bolts in a criss cross pattern, and make sure to put the spacer in. The spacer spaces the bolts out from the flywheel a bit.
6. Put the clutch disc alignment tool through the hole in the clutch disc. Now, take the clutch disc with alignment tool and put it onto the flywheel, with the end of the tool engaging the pilot bearing. Also, check to make sure the clutch disc is installed the right way around. It should be marked "flywheel side" on one of the sides. Once it is lined up, install the pressure plate over top of everything, and tighten up the six bolts, again in a criss cross sequence. Once you have torqued down the pressure plate bolts to the proper torque, remove the clutch alignment tool.
7. Now, find the wiring plug from your 5 speed transmission that goes to the reverse light switch on the transmission. The plug has 2 wires in it, and is the only plug on the transmission. These wires will need to be run to your existing back up light switch wiring, which can be found on the 4 wire plug that was connected to the automatic transmission shifter. The two wires for the back up lights are the skinny wires on the 4 wire connector. Cut the wires from the plug that went to the automatic transmission shifter, and connect the wires from the new plug to the two cut wires.
8. You now need to install the clutch pedal. The easiest way to do this is to swap the whole brake pedal / clutch pedal assembly. Also, there may be differences in the assembly between cars with power brakes and cars without power brakes, so make sure you have the right one. Once you have establised that you have the right brake / clutch pedal assembly, disconnect the clip that holds the master cylinder pushrod to the brake pedal, and slip the pushrod off of the pedal. Now, look carefully at the assembly from under the dash, and you should find one or two bolts that connect the assembly to the firewall. Remove these bolts. Next, move to the engine side. You need to remove one of the master cylinder nuts (non-power brakes), I believe the left one. Leave the other nut in place to hold the master cylinder on to the firewall. Also, there are about 3 other bolts on the firewall that you need to remove. You will need to determine which bolts these are. Once all the bolts have been removed, Get under the dash and pull out the old brake pedal assembly. Work carefully to prevent snagging the assembly on the under-dash wiring. Once the old assembly is out, install the new clutch / brake pedal assembly the same way that the old assembly came out.
9. Remove the rubber plug that is in the clutch cable hole. Install the white plastic clutch cable adjuster sleeve / bushing in the hole. Some sort of goopy sealant is recommended to hold the sleeve / bushing in the hole and to keep water out. Now, put the pedal end of the clutch cable through the hole in the sleeve. Get under the dash of the car and hook the eye on the cable over the hook on the top end of the clutch pedal. Push the eye down all the way. There is no retainer on this end of the cable, it is a friction fit. Back under the hood, you will find a metal tab / clip on the left shock tower. The hood release cable is running through this clip. This clip is also used to retain the clutch cable and prevent it from banging around into the engine. Clip the cable into the clip. Once that is done, run the remainder of the cable towards where the transmission will be, and let the cable hang there.
10. The clutch starter switch, located on the clutch pedal, may be connected at this point if you wish. You don't need to hook it up, but it will prevent you from accidentally starting your car while the clutch is not pressed. If you dont hook it up, connect the two remaining (thick) wires from the automatic shifter plug together. If you do wish to connect the clutch starter switch, just connect the two wires from the automatic shifter plug to the two terminals on the switch itself.
The car should now be ready for Installation of the 5 speed.
Installation of the 5 speed
1. First of all, you need to get your 5 speed on a hydraulic jack so that you can position it correctly under the car. Put the jack under the 5 speed so that the transmission will balance on (ie. not fall off) the jack. I would suggest tying the transmission to the jack with rope at this point to prevent it accidentally falling off of the jack. Also, put the transmission in gear (5th preferably).
2. Move the transmission into rough position under the car, and jack it up until the transmission input shaft roughly lines up with the center of the clutch.
3. While aligning the bellhousing alignment pins, push the transmission towards the engine, while also turning the output shaft of the transmission to allow the input shaft to engage the clutch disc. This is the difficult part of the swap. You will need your assistant to do this. Make sure that everything is in line, and try to get the bellhousing to come up flush with the mounting flange on the engine block. While holding the transmission in place, put in two of the transmission bolts by hand to hold the transmission in place.
4. Install the remaining bellhousing-to-engine bolts, and torque all eight bellhousing-to-engine bolts to 25 ft-lbs.
5. Install the dust cover with it's 4 bolts
6. Position the 5 speed transmission crossmember on the frame of the car and loosely install the crossmember-to-frame bolts. Install the crossmember-to-transmission bolts. Tighten the center (big bolt) to 33 ft-lbs, and the two other bolts (small bolts) to 21 ft-lbs. Then, tighten the crossmember-to-frame bolts to 40 ft-lbs... Be sure that you don't strip the crossmember-to-frame bolt holes. Also, note that two of these holes were used with the automatic transmission crossmember, but two of the holes were not used. You may want to run a tap through the holes to clean any rust out of the threads.
7. Re-install the exhaust if you removed it. You may also remove the jack at this point.
8. Connect the clutch cable to the clutch fork, and adjust the clutch. There should be about 1" of free play at the clutch pedal. Rough adjustments may be made at the ball stud if necessary. Final adjustments are made at the clutch cable at the firewall under the hood. On a stock clutch cable, there is an E clip that engages in the various slots in the clutch cable to allow you to take up the slack in the cable. The E clip setup is weak and prone to breakage. I would recomment using a worm type hose clamp placed around the grooves where the E-clip used to go. Just adjust the cable to where you want it, and tighten the clamp. Also, install the return spring which connects between the clutch fork and the crossmember.
9. Connect the speedometer cable and back up light switch. *Note- use the plastic gear that was originally used in the 5 speed, NOT the plastic gear from the automatic. They are NOT the same and ARE NOT interchangeable. The 5 speed gear is usually yellow in colour, while the automatic gear is usually blue or green in colour.
10. Install the 5 speed driveshaft.
11. Fill the transmission with oil specified, which will be either 5W30, Automatic Transmission Fluid, or 80W90. Use a manual oil pumping device, suction gun, or whatever other method you can think of. The transmission holds around 2-3 liters of oil.
12. Lower the car, and install the shifter and shifter console.
13. Test drive the car. Make sure all the gears work (including reverse!) and that the clutch is adjusted properly. Check to make sure the reverse lights and the clutch starter switch (if installed) work.
Your car has now been converted to a 5 speed transmission from the automatic. An added note: Most automatic cars had a lower factory axle ratio (ususlly 3.62) than 5 speeds had (usually 3.43) from the factory. By leaving the automatic transmission rear axle gears in place, you will have improved acceleration over a stock 5 speed setup.
Results:
I found the low speed acceleration of the car with the 5 speed to be phenomonally better than it was with the automatic. The tires will now squeal in first gear. Highway use is much better, as the RPMs have dropped from about 3400 RPM @100kmh to 2900 RPM @100 km/h. Also, the car will now cruise at 120 km/h easily, which was difficult to maintain with the automatic. Top speed has also increased from about 150km/h with the automatic to around 160 km/h with the 5 speed. People look at you funny when they get passed by a screaming chevette doing 160 km/h at 5400 RPM. Of course, that was just a test run only, and I didn't maintain that speed for long at all for fear of police and engine failure. Additionally to all those benefits, I now get about 34 mpg in mixed driving, compared to 29 mpg with the automatic.
Complaints / Problems with the 5 speed:
The transmission itself is a plenty strong unit for chevette use. I have experienced problems with the clutch fork working it's way off of the worn out ball stud. The reason for this is the increased load from the new aftermarket "heavy duty" clutch. The clutch itself sure seems to be heavy duty. Pedal effort with this clutch is very high, but the clutch has excellent grip and refuses to slip. The car is currently parked due to this recurring ball stud issue. I am working on a conversion to an F body style T5 hydraulic clutch linkage at the moment.
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