Chapter 1

Parts and Compatibility

At the end of the chapter I will list a lot of parts that will be needed to perform the conversion. Since I work at a dealership, I get a real decent discount on parts. So you will notice that a considerable number of my parts are new. Also because I don't have any time to get out to the junkyard it was easier to purchase the things I needed so that the fit and feel would be like new. Truth being told a lot of the parts were reasonably priced and were well worth buying new as to used.

The first thing to consider is what transmission to buy and what to look for. There are 2 types of manual transmissions released in the 5th generation Celica, the C-52, and S-53. I recommend buying the S-53 over the C-52, because the S-53 is the performance option transmission. The S-53 has tighter clearances internally and is heavily built. The S-53 uses ATF for lubricant instead of gear oil, because gear oil can't get into the tighter areas. The easiest way to tell the two apart when shopping at the junkyard is, the S-53 has the shift cable holders cast onto the transmission near the speedometer cable, and the C-52 has a bracket that bolts onto the transmission. One way to remember the two apart is "C" is for commuter and "S" is for sport.

If I had limited budget to work with I wouldn't skimp on the transmission, after all this is the focal point of the conversion. Most yards don't have different prices on the two transmissions but if they do go for the better one, you won't be sorry.
When I bought my shifter cables (new) the computer stated S-53 so there may be a difference in the cables from the C and S types.
Good news now, your axles and starter will work without any modification. There are holes in the floorboard already for the cables, so that means less cutting and easier installation. There are hangers on the firewall for the brake lines that have an extra space for the clutch line.
When at the junkyard there are a few things to pick up for the conversion.

  • First is the transmission mount, they are different and won't interchange.
  • Second is the reverse light switch connector, from on top of the transmission. You need to snag the wire connector and about 6 inches of wire for the wiring work in the last chapter.
  • Third is for those of you who have cruise control and want it to still function after the conversion is finished. Get the cruise cancel switch from the pedal bracket. That is if you don't get the bracket used.

Parts List

With part number when available

Transmission junkyard
Clutch master cylinder 31410-20470
Clutch pedal bracket 55107-20330
Clutch pedal 47101-20430
Clutch cancel switch had on hand
Brake pedal 31301-20380
Pedal pads x2 31321-14020
Clevis pin 90249-08143
Clevis pin bushing 00000-00000
Wave washer 90206-08001
Clip 90468-16142
Bolt clutch pedal hinge 90101-10015
Nut 94110-51000
Bushing pedal x2 90386-13015
Collar shaft 90387-10003
Cushion pedal stop x2 90541-06036
Return spring 90507-14029
Shifter assembly 33530-20550
Shift cable 33821-20682
Range cable 33822-20252
Cable clip x4 90468-14016
Clutch line lower came on trans
Clutch line clip x2 00000-00000
Slave cylinder came on trans
Trans mount 12372-74200
Flywheel junkyard
Flywheel bolts 00000-00000
Clutch pressure plate throw out pick your brand
Pressure plate bolts x6 don’t have # on hand
Trans bell housing bolts x3 grab ‘em at the yard
Starter relay junkyard
Clutch start switch 00000-00000
Flywheel bolts
90105-10071
Pressure plate bolts
90119-08079
Slave cylinder rod
31473-32010 (not incl. with a new slave)
Upper clutch hard line
31481-20600
Lower clutch hard line
31482-20400



You will also need various clips and brackets for clutch lines -- if you can't pull them off a junker, then goto the dealer as they should be under $50.

-Buy master cylinder, rubber clutch line, and slave
cylinder new. They are hard to find used and in good
condition because they are easily damaged. Check
around at your dealer and parts stores and spend what
youd like. Keep in mind that this project may take
over 30 days, so a warranty that lasts that long might
not do you any good.
-Find a junkyard car and get the following: shifter
assembly and cables, clutch and brake pedals,
transmission mount (top and driver's side of the
transmission), green starter relay in passenger kick
panel, clutch hard lines (hard to find in the US new
and also relatively expensive) and any/all hardware
that is related. There are many odd sized bolts that
you will need.
-Plan on spending a lot more time if you need to buy
parts new. Average wait to get new parts in is
probably 3 days, but I had to wait for over 2 weeks to
get my clutch lines in because nobody had them in the
US (they ended up coming from Japan).
-In my 1992 GT, although the underhood wiring was
correct, none of the wiring was in the car that the
write up uses. The starter relay was wired in near the
driver (I cant give specifics, but it gets power and
ground, a wire from the clutch pedal bracket to know
when the clutch is down, and a wire to send power to
the starter when the clutch is down). Clutch cruise
cancel switch must be wired in series after the brake
cruise cancel switch.



Chapter 2

Master Cylinder Pedals & Hydraulics

One of the first things I need to stress in this chapter is that you need to make sure you have the pedal bracket pushed up all the way up in place and touching the firewall before you mark the holes in the bracket.

With that said let's get started with the conversion. First you will need the pedal bracket and one 12mm head nut. The thread size is 8mm x 1.25.Remove the driver's side lower dash cover, the metal crash plate, and the air tube. You can remove the brake pedal now. There is one bolt holding the pedal in place, and one spring. Remove the nut and slide the bolt out. When the pedal is removed, notice the two plastic bushings and the metal center bushing that the bolt rides on. This is the same set up for the clutch pedal later.

Lay in the floor and look up at the under side of the dash. There is a threaded stud protruding down just behind a box mounted on the frame. The box is the headlight retract control relay. You will probably need to remove it to ease the modification. Next put the bracket in place and put the nut on and thread it down until it is almost snug. You want the bracket to be movable but still be as far up in place as to resemble the installed position. The first picture is of the cut out in the insulation on the firewall. All cars have it and the picture of mine unfortunately was where I had my amp power cable run through. So I will have to work around it and cut my hole a little differently. But you should be able to mark yours and drill without complication. In the picture on the right you can see the bracket in place ready to be marked. Use a center punch or an awl to mark the center of the holes to be drilled. Take a Black marker and make a ring inside the center hole on the edge to give you a template on how far to grind to. If you use a marker and don't center punch your drill points, the drill could walk across the metal and mess up the alignment. THIS IS VERY IMPORTANT!!!!!!! This is the only critical part. Make sure the holes are well marked before drilling.

  • firewall w/ insulation pop out removed
  • bracket in place ready to mark firewall

Now it is time to drill, don't be shy now this is the big step. Set up the drill with a 1/8inch drill bit and drill all 3 holes. Next drill the 2 mounting shaft holes (top left and lower right) with a 3/8inch drill bit. Now that's it for those two. Next get the biggest bit you have and drill the center hole. I ended up using a 90* grinder and a carbide porting and polishing bit. Air was such a big help here, but a good bit in an electric drill will get the job done in decent time. Grind the center hole out to till the black ring is gone but make sure to test fit the master cylinder several times to ensure proper fit and to see which way to go with the grinding. Take your time. Make it right the first time, you don't get a second chance.

Once you have the master cylinder holes cut out you can reinstall the pedal bracket loosely and insert the master cylinder into the bracket through the firewall. You need two nuts to lock down the master cylinder.

  • Test fitted notice the old hole
  • master cyl. & bracket in place

Now on the bottom right of the bracket there is a hole for a bolt. I opted to not put this bolt in right now. One day I probably will. Notice that I took off the end of the master cylinder for easier fitment of the master through the firewall. Once you get this together go ahead and loosely install it.

Clutch Pedal

Next we need the 2 large bushings, collar shaft, bolt, nut, clevis pin, clevis pin bushing, wave washer, pin, return spring, clutch pedal, brake pedal, pedal pads, and cushion pedal stops. WOW that took a lot off the inventory list.

Assemble the pedal, collar shaft, and large bushings. The small clevis pin bushing goes in the clevis pin hole to take up the extra space and cut down on squeaks. Put the pedal stop cushions in place. They should be easy enough to see where they go, but if not one goes for where the clutch start switch will hit the pedal, and one where the cruise switch will hit the pedal. Next put the pedal up in place use a little grease on the bolt and insert it through the bracket and pedal. Make sure the end of the clutch master cylinder is in place around the pedal before you push the bolt through. Install the nut and tighten. Install the wave washer under one end on the master cylinder and slide the clevis pin through the master cylinder end, wave washer and pedal. If memory serves me correctly the pin needs to be inserted from right to left. This is because the pedal return spring has a post that it attaches to on the left side of the pedal. Next install the clip through the hole in the clevis pin. Attach the return spring to the end of the clevis pin on the groove and up on the frame on the post that has the hole in it. Install the rubber pedal pad.

Brake Pedal

The brake pedal is very simple. Take the old bushings and collar shaft out of the automatic pedal, remove the pedal pad, and put them in the new manual pedal. Install the pedal in the bracket. Install the brake pedal clevis pin, lock pin, and return spring. Make sure the brake light stop switch is still adjusted properly. It should still be ok.

  • brake pedal w/ bushings removed
  • clutch pedal installed

Hydraulics

I am going to write this section as if the trans is already in the vehicle and all that is left is to plumb it in. When I purchased my transmission from the junkyard it already had the slave cylinder and lower metal line with mounting bracket on the transmission. The slave was brand new so that was one less part to buy.

First thing is to remove the coil, igniter, and brake booster line from the firewall. Take the upper line and set it in place to figure out which end is up. I had to loosen the booster from the firewall a little in order to slip the line in behind. Fasten the line to the master cylinder and leave loose. Next snap the line in place in the brake line support holder. Now you can put the line support in place on the proportioning valve. This is important to have in place. The support steadies the line and keeps vibrations from damaging the line. I made one from a brake line holder off an old strut. I just took a hacksaw and cut it off and bent the angle for mounting it. Shot it w/ some paint and installed it. Works perfectly. Once in place you need to install the rubber hose. Lock it in place with the clips. Next install the lower line and the slave. Now we are ready to bleed the system and set pedal height.

  • Removing the coil igniter and booster line
  • Putting the upper clutch line in place
  • Upper line installed
  • Bracket I made from strut brake line support
  • Bracket installed on valve
  • photo of a factory line support

Bleeding the system

First go through and snug up all the line connections. You will need someone to help bleed the system. Have someone pump the pedal three to four times. Then open the bleeder valve. This will take quite a few repetitions to get the fluid to run clean and clear of air bubbles. Once this is done you need to set the pedal height. Typically the clutch pedal is set at the same height as the brake pedal. Adjust the height by turning the rod on the clutch master cylinder that fastens the master to the pedal. Turn it until the pedals are the same height. Then lock the nut against the bracket.

Now, do you have cruise? If so you will need a cruise cancel switch for the pedal bracket. If not you need a bolt and nut to go where the cancel switch would have gone. You can see the threaded hole at the top of the bracket for the switch. Insert the bolt or switch in the hole and run it down until it contacts the pedal pad. If it's the bolt, turn the bolt ½ turn and lock the nut down. You're done. If it's the cruise switch let the pin in the switch contact the pad and turn the switch until the metal threaded shaft just touches the pad and lock the nut down. We will wire the switch in, in the electrical chapter. Now we are done with the pedals and hydraulic part. Give yourself a pat on the back for me. You have just completed the hardest part of the conversion. It gets easier from here on out.

Chapter 3

Shifter Cables and Shifter

Disconnect the battery to prevent electrical damage before continuing with conversion. To look at the pictures below you will think that tearing down the dash is a daunting prospect. But it is easy. First remove the glove box. There is one screw in each bottom corner, and three in the top of the box inside. Now the center console needs to go. There are two screws on each side and two inside the center of the console box. Don't forget to unplug the power mirror switch. Next remove the shifter cover, radio, and shifter console. When these are out the lower dash will look very stripped.

  • Shifter console removed

Now you can see the dash support brackets on each side of the hump. On the right bracket there is one nut up top, and two bolts on bottom of the bracket just below the carpet line. There are three 10mm bolts that fasten to the support. These will have to be removed also. One is a ground wire, one is a plate supporting the harness, and one is holding a bracket on a black box perched between the supports. Lift up the blue box off its mount and let it sit there. Now I'm sure you already have the battery disconnected. If not do it now.

Now disconnect the air bag computer harness, the ECU harness, along with two body harness connections next to the ECU, and the circuit-opening relay. Use a torque bit and remove the air bag computer. Then remove the ECU. With that done there are four bolts holding the shifter to the floor, save them to be reused later. There are two wire connectors on the passenger side of the shifter. Disconnect the wires and unbolt that baby. Pop up the shift cable-housing clip, and the clip on the shift cable itself, and get rid of the shifter. Now when you look up under the heater box you will see the cable going down into the floor and looking in further, you will see the block off cover for the manual shift cable hole. There is also another access cover outside on the firewall. That's because the firewall is double walled. But don't worry it's only about two inches deep.

Now we need to remove the automatic shift cable from the body. Jack up the car and make her safe to get under. You need to remove four bolts on the exhaust support mount to the body behind the rack and sub-frame. Hidden under the mount is a bolt holding the cable in place. Remove the bolt and discard. Now you can cut the cable and remove it in two pieces, or remove two10 mm bolts that are on the cross member holding the cable down, remove the clip and the nut on the end of the cable, then back feed it into the interior and toss it in the pile.

  • Clip and nut on the cable
  • Shift cable plug outside above the rack
  • Shifter and cable access holes
  • Pic of mount and bolt on shifter cable

Instead of buying a plug, I removed the plate and rubber seal from the automatic cable and used sealer to fill the hole in and reused it to seal the body. Pack it full of sealer and let it sit over night. Install it tomorrow. Pull the manual cable cover off the hump and remove the cover off the outside as well. Take the cables out of the package and you will notice that the rubber seal plate is fix mounted to one of the cables. Take the other cable and set it in the empty hole. Next put the metal support on over the cables and feed them in through the firewall about six inches. Go outside and from the driver's side pull the cables out and to that side. When they are about two feet out you can go back inside and set the plate in place and bolt it down. Now take the manual shifter and reuse the bolts that held the automatic shifter and bolt it to the floor. She bolts right where the auto came out. No modifying needed. Set the cables into the front of the shifter and lock them in with a pair of clips. Hook the shift cable up with the funky clip and the range cable with a hairpin clip. You can use the one that came off the auto shifter cable. On the outside cable body plug, I took a drill and a 3/8 inch drill bit and drilled two holes side by side and used a razor blade to cut out a section for the cables to fit through. Slip it over the cables and fit up to the wall. Reinstall the metal support and lock it down. The cables are done. All that is left is to reinstall the floor plug, ECU, air bag computer, support bracket, and interior covers. Not too bad was it.

  • Pic of the funny clip on shift cable
  • Cables coming through firewall


Chapter 4

The Transmission

The transmission work isn't hard at all. The automatic is one heavy son of a gun, so you are going to shave off a lot of weight. COOL! You are going to have to replace the transmission mount. Not a big deal, but it's around $80 new. If you can, get one when pulling the transmission out. Basically follow a repair manual for getting the transmission out. Pull the starter, speedometer cable, splash shields, passenger CV axle, lower control arm stiffener, cross member, torque converter cover, and block support. Pull the converter bolts, mount bolts, and then the bell-housing bolts. Pretty plain and straight forward removal. I didn't remove my passenger axle but you may want to for easier installation. I recommend cleaning out the trans cooler at this point so it doesn't drip on you forever.

Now remove the flex plate and slap on the manual flywheel with the longer flywheel bolts. Set up the clutch assembly with the new pressure plate bolts.

  • Under carriage with auto in place
  • Cross-member and converter cover removed
  • Clutch and flywheel in place
  • Manual transmission installed

Once the Flywheel and clutch assembly are in place, install a new throw-out bearing. Now install the transmission. Use the three longer bell-housing bolts and remember that the 14mm bell housing bolt next to the axle is the same on both auto and manual. Install the transmission mount. After the transmission is locked in, you can reinstall the lower converter cover and block support. There was a 12mm bolt in the dust shield on the back of the block above the axle, that one has upsized to a 14mm. Install the driver's axle, starter, speedometer cable, cross members, and DON'T FORGET TO FILL THE TRANSMISSION. Leave the driver's splash shield off for the electrical work.



Chapter 5

Wiring for Dummies

Sorry for the pun, but wiring is one of the most complicated and ominous parts of a car that can scare the most adventurous person away. I wanted my car to work like factory, so that means that the cruise and starter had to work differently. The starter has to keep the car from starting until the clutch pedal is pressed, and the cruise has to work. It has to shut down when the clutch is depressed so the engine won't over-rev. and blow. So not only did I have to figure out the way to wire the car up, but I also had to come up with a way to do it so that someone could follow me and not need an engineering degree to understand what I was trying to accomplish. So let's get on with it.

For those of you who can read a schematic and understand the lingo I will sum it up for you so I don't bore you anymore. And then the long version with pretty pictures for all the rest. HAHA

Wording for the Savvy

Start power flows from start switch (I12 pin 7) to harness connector EB1 pin 4. Shift wire in pin 4 to pin 2 position. Next go to N1 and jumper pin1 and pin2 together. I recommend using shrink wrap connectors to reduce chance of corrosion. Install a flat four-pin start relay in R/B 4. Install start cancel switch on clutch pedal bracket. Locate connector C12 above J/B 1. Connect to start switch. Now locate C18 and connect to clutch cruise cancel switch. Next on connector N1 pin 3 and pin 4, wire to the reverse light pig-tail we picked up at the yard. Doesn't matter which way you hook it up. The last connector is O1 for o/d tape it off and seal up harness. Take her for a test drive.

Step by Step for the Novice

In the first picture here you see on the left is the neutral safety switch connector. The ungloved hand is pointing at the reverse light switch on the transmission. Now remember that I said to get the reverse light switch wire connector at the yard. Well, here is where it comes in. There are four pins on the neutral safety switch connector. Cut the connector head off and you have two large black wires, and two small red wires. Connect the two wires for the reverse light switch to the two small red wires. Make sure that the connector wires are about 6 inches long, so you have plenty of room to move the harness around. Next connect the two black wires together. This will let you start the car, even in gear so be careful. In the second picture with the torch you will see two other wires in the background. They are from the other connector on the transmission, which is overdrive. Cut it off and cut the wires off at different lengths so they won't be able to touch each other when wrapping up the harness. You will do nothing with them.

  • Neutral safety switch connector and rev. switch
  • Shrink-wrapping with a micro torch

Now that we have jumpered the neutral safety switch lets get the rest of the system in place so we don't run anything over. In the pictures below you will see the harness junction connector EB1. This connector is located in the engine compartment on the passenger side in the rear behind the strut tower. The line in the picture is the power steering hi-pressure line. Of the two connectors here we want the one on the inside, more toward the engine. As you can see there are three wires in the connector and one empty spot. We need to move the black wire from the spot it's in (pin 4) up to the empty spot (pin 2). To do this we need to remove the plug on the back with a pick or something sharp. Then you need to lift up the connector pin lock. It's the white thing inside the connector. You just lift it up with a pick and take it out, as you can see in the left picture, it's popped up and ready to remove. Once out, turn the connector so the tab is on top. Looking down in the pinhole you will see a tab that has to be picked up in order to release the wire pin. If you have trouble seeing the tab look at the empty hole to see the tab. Flip up the tab while pulling gently on the wire. Slide out the wire and move it up to the empty hole. Reinstall the lock, install the plug in the newly emptied hole and reconnect wiring harness.

  • Starter wire connector, passenger side of engine bay next to power steering line
  • back of connector w/ plug removed

At this point the car can't start again. So now we turn our attention to the inside. On the passenger floor, remove the kick panel and you will see a small relay box. It's the blue box on the left. This is R/B 4. On the left picture you see the box, as it is when you start. And the right is with the relay installed. This is all there is to do here. Reinstall the kick panel.

  • Relay block without start relay
  • Relay block with relay installed

Now for the start switch, you will see up above the main interior fuse box (J/B 1) the wire connection for the start switch. Pull it down from where it is taped to the main harness. Install the switch on the pedal with the wire coming down and out from underneath. There is a locating pin on the switch to make getting the angle correct. Clip the connector into the hole provided on the bottom left edge of the pedal bracket and connect wires. Now the start circuit is finished. You can only start the car when you press the pedal to the floor.

  • J/B 1 left kick panel showing clutch start wire
    coming down to the pedal


So, let's recap the start circuit so you can understand what you have just done. The interior harness is pretty much the same for auto and manual cars. The harness under the hood is a bit more specific for auto vs. manual. When you jumpered the neutral safety switch you made a solid path from the key to the starter with no interruptions. Now manual transmission cars use pin 2 of the connector EB1 in the corner. Automatics use pin 4. Unfortunately there is no wire for us, so we are going to rob the auto wire and use it for our needs without having to run a whole new wire. All we have to do is move the wire so we can get it on the same circuit as the relay. This way the relay will control the power running through the wire. On the interior part, the relay always had power at the box. So when we moved the wire we gave the power some place to go. But we have to ground the relay in order to get it to work. This is what the pedal switch is for. All it does is ground the relay causing the relay to turn on and start the car. Remember that all a relay is, is a way to remotely turn on a high voltage component using a low voltage switch. This reduces the size of the dash harness. Below is a schematic of the starter circuit. Notice that both automatic and manual transmission components are shown.

Now all that is left is to wire the cruise control cancel switch so the cruise will shut down when the clutch pedal is pressed. Basically all you have to do is to install the switch and hook up the wire. The connector is right there. Just remember that the switch doubles as the pedal bump stop. Don't run it down too tight and let it put pressure against the pedal. Other wise it can help to ruin the clutch. In the first picture you can see the wire for the cancel switch and the pedal stop bolt for the clutch pedal to rest against. Remove the bolt and install the switch. Screw it down until the threaded shaft just touches the rubber stopper. Lock the nut and hook up the wire. You are finished. Go for a test drive and have some fun.

  • Clutch cancel wire
  • Switch installed on pedal bracket

I hope you have enjoyed this article and have learned a few new things from it. I enjoyed converting the car a lot and found it a little challenging and yet it had a foreseeable end within reach. The wrench work can be done in a weekend and the wiring can be done in the same weekend if you have researched the harness and have the switches on hand. All the responsibility for safety features and wiring is yours. I did this to my car and wrote this article to share my experiences with you and offer this only as a means to inspire you. So if you blow you're car up or burn it down don't blame me. Follow the schematics for your specific vehicle. But I can tell you that this conversion has improved my fuel mileage and over all performance. Not to mention shave off a lot of weight.

Scott MDT


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