Here is a repost from club202 for my transmission drop (2000 C230K).
First I want to mention a couple of important things.
1. I removed the transmission without a special transmission jack and with only 17.5 inches of clearance from floor to jacking point of car. The transmission is only about 14 inches tall at the tallest point. However other have rightly recommended that the higher you can get the car the better it will be on your neck and overall safety.
2. The transmission must be removed with the torque convertor attached! Without the torque convertor the transmission WILL NOT come out. Ask me how I know.
3. The exhaust system does NOT need to be removed from the car.
Transmission Removal steps:
1. The very first thing to do is jack the car up to as high as you can get it. I had no issues raising the car from the centre support directly behind the oil pan. I used a 3 ton jack to accomplish this. The rear of the car does not need to be jacked up. Once you have carefully and slowly raised the car, position jack stands underneath the jacking points. Get another pair of jack stands and position them underneath the control arm support frame (you can see this in the pictures below).
2. Put the transmission in Neutral, apply the parking brakes, and chalk the rear wheels for peace of mind.
3. remove the plastic shield covering up the oil pan area
4. Get ready to drain the transmission oil from the transmission pan, use a torx bit to remove the oil pan bolt, let most of the oil drip out. Trust me you will have other things to do.
5. You may want to drain the torque convertor also. I didn’t really care about that. The worst thing that happens if you don’t is that you will get about one liter of transmission oil on your floor. To drain the torque convertor get a 27MM socket for the crank bolt--and rotate the engine CLOCKWISE until you see the torx head bolt on the torque convertor. Remove the bolt, drain the oil.
6. There are two hard oil lines that bolt onto the bottom and top of the transmission, these send hot oil to the radiator and return cooled oil to the transmission. Get wrench and gently undo the head bolts. There is very little torque required to get these off. Generally there will be some oil here that should just drain into your oil catch pan.
7. These hard lines are also bolted to the engine oil pan for support, undo the torx head bolts so that you can move the hard lines freely.
8. While you are here and admiring the underbody of your car, look towards the exhaust side and you will see the oxygen sensor and the exhaust manifold. Remove the two bolts that hold the exhaust pipe to the manifold. The exhaust is till held in place by a bracket that’s bolted onto the bell housing.
9. Now up to the engine side. Trace the oxygen senor wire to your emission box and unplug the sensor. You do not need to remove the oxygen sensor from the exhaust pipe. You just need to move the whole exhaust up and away so you have more room to unbolt the transmission from the engine.
10. If your transmission oil is in good condition, save it. Put you dirty tools in it for a good cleaning.
11. While the oil is draining head towards the back of the transmission. Support the transmission (under the pan is fine, I caused no damage to the pan) with a regular 2 ton jack and a couple of pieces of 2x4s. DON’T just put the jack metal to metal. You may have the luxury of buying a transmission jack. By all means please do.
12. Now remove the four bolts for the transmission support bracket. This is where the transmission mount sits. Sorry I don’t have pictures for this procedure but it’s pretty straightforward. You may have to put tension on the jack before you take out the last bolt.
13. Since you are in the area you better remove the exhaust support bolts from the bracket that is attached to the back of the transmission. I left the bracket on the transmission and just unbolted the exhaust from it.
14. You should now be able to see the flex disc on the transmission output shaft. You need to remove only THREE bolts. I believe they are 19MM. Make sure you mark the drive shaft and output disc on two sides so you can then re-align appropriately.
15. Now here is the tricky bit, you will probably be able to get two of the three bolts out but one of them will surely by at the 12 o-clock position. To get to it you will need to rotate the rear wheels so that drive shaft rotates and reveals the hidden bolt. You can do this easily by jack the rear of the car. I accomplished this by jack the car from the rear hook. Its only for a few seconds, you want the car back down on rear wheels.
16. Once all three bolts are removed, get a pry bar or strong flat head screw driver and pry the drive shaft away from the flex disc. You may have to release the tension on the transmission support jack to persuade the transmission to drop a little bit.
17. No head back to the front of the car. There are a total of ten torx head bolts holding the transmission to the engine. You can remove 7 from underneath the car and three from the top.
18. These bolts were the most difficult part for me. But for you they will be piece of cake learning from my mistakes.
19. Go ahead and break the torque on the lower torx head bolts and then remove them. There isn’t a lot of
torque on these so don’t rush with the air gun. I had only two stubborn bolts that needed the air ratchet. The others where removed with my fingers! Just a note that one of the torx bolts is a double for the ground so that will come off naturally. I think it’s in one of the pictures. There are a couple of bolts near that seem impossible from the under side. Believe me they are not.
20. Now that you are holding seven torx bolts its time to put some tension on the transmission support jack and raise the transmission up as much as possible. This will pivot the engine forward revealing an extra inch for you to remove the top three torx head bolts.
21. I removed the heat shield and the removable firewall frame all greater visibility and maneuverability. To remove the heat shield and metal frame you will need to remove what looks like a breather line from the booster to the intake.
22. next you need to remove the coil cover and then remove all ignition coils and wires
23. Next remove the several 10MM head bolts holding the valve cover on. Hey this is a great time to replace your valve cover gasket and ignition coil seals. I am doing this. There is one 10MM head bolt at the very back of the valve cover; it’s almost hidden so make sure you remove that one before trying to pry the cover off.
24. If you haven’t replaced the gasket recently your valve cover will not budge. I tried hitting it gently with a rubber hammer—no luck. I tried pulling upwards from the engine oil cap—no luck. Then last resort was to get a clean flat head screwdriver and gently pry at the corner where the metal is thick. This did the trick for me and I was able to lift the valve cover off. Cover the exposed valves with a cloth or paper towels.
25. Get an 11MM wrench and a pipe to break the torque on the three torx head bolts. You will be surprised that after you break the torque you will be able remove the bolts with your fingers. Now you have all bolts removed from the transmission to the engine. YAY!
26. Here is the trick, to remove the transmission you have to pull the torque convertor with it. Get your trusty 27MM socket and ratchet on an extension and rotate the engine CLOCKWISE and look through the opening through the flywheel. There are SIX 13MM head bolts that hold the torque convertor on to the fly wheel. Remove all six bolts you will have to rotate the engine after each one. I had my neighbor give me a hand with this. So get a buddy.
27. Lower the transmission support jack to separate the transmission from the engine. Just enough so you can get a pry bar and separate the torque convertor from the flywheel and get it all the way inside the transmission bell housing.
28. Now you can lower the transmission several inches.
29. Go over to the driver side and get under the transmission, on the driver’s side of the transmission you will see the shift linkage, it’s held in place with a clip. Remove it and push the linkage out.
30. Now go over the passenger side and look up around the middle of the transmission you will see a 10MM head bolt that holds the fill tube onto the transmission. Loosen the head bolt with a wrench and should be able to wrestle the fill tube out from the engine compartment.
31. Because I didn’t have a transmission jack I wrapped nylon strap around the bell housing and positioned my support jack towards the rear of the transmission. I had my buddy slowly lower the strap as I lowered the jack. Once low enough I slipped a 2x4 under the transmission and the pulled it onto a waiting piece card board.
I wrote all of this from memory so I may have missed a bolt of two, but I don’t think I have missed anything important that I know will save you a lot of headache and hassle.
Besides the 27MM and torx bits and sockets no other special tools were required.
I will be updating this post for the reinstall! So stay tuned.