Well, I had some time this past weekend to swap out my clutch, so I figured I'd share with you all some of my experiences. Stock clutch lasted 134k miles; mainly highway driven by previous owner. I decided to drop the transmission instead of pulling the engine; I wanted to get the full experience and see just how much fun I could have! If you have the right tools and patience, a lot of patience, it's really not terrible. But I definitely wouldn't recommend it to everyone. Everything took me about two full days of work, with breaks along the way. I sprayed just about every bolt with Aerokroil a few days before tackling this. I also sprayed it along where the engine and transmission meet.
Items I chose to use:
-8 Flywheel bolts (800610740)
-Red Loctite for clutch bolts (your call)
-Transmission fluid (have 4L ready; mine took about 3.7L) check dipstick on level surface
-Brace to support weight of engine (2x4s and ratchet straps) Thanks BBPeik
-Way to support/lower/roll transmission safely
-More ratchet straps, pry bar, chisels (separating my engine and trans was a chore)
-Grease (I used on all metal/metal surfaces)
-Degreaser (to clean clutch/flywheel surface and other misc parts)
-Perrin WRX brass shifter bushing and washer (great, cheap mod!)
-Pen and paper to label nuts/bolts removed
May be wise to have on hand:
-Rear main seal (just in case yours is leaky)
-Camera (snap pics of things to ensure they go back together correctly)
-Sharpie or another way to mark the position of prop shaft, steering universal joint, and flywheel
Potential hang ups:
-Removing engine mounts (especially driver side...be ready for it to take a long time)
-Separating engine and transmission (don't give up; it will eventually spread apart)
-Mating engine and transmission (play around with the angles a lot and at a minimum, grease dowel pins)
-Steering universal joint (I managed to put mine on a notch off so had to take it off and reinstall)
Purchased after completion:
-Perrin intercooler coupler (PSP-ITR-321BK) (mine was in rough shape - check yours if you haven't)
-An hour long massage and cheesecake
I put the car in neutral, with e-brake off; chocked wheels. Disconnected the battery. Removed plastic engine cover. Removed intercooler.
Disconnected neutral and back-up connectors, transmission ground wire, engine harness connectors (all right below intercooler). The circles are potential mounting points for engine and transmission.
Removed clutch operating cylinder and hung out of the way. Disregard top arrow; this bracket comes off when top starter bolt is removed.
Begin to remove starter. The top bolt of the starter is easily accessible, but the bottom one is no fun; we'll get to it shortly. Removed two bolts on passenger side top of transmission.
Now the real fun...the dang engine/transmission mounts. Put the engine brace in place and use a couple ratchet straps to support the engine and transmission. I placed towels between brace and vehicle.
There's a spot in the bracket of the plugs that were disconnected earlier to support the passenger side rear of engine. I don't remember exactly what I hooked onto for driver side rear, but I know I found a good spot quickly. Ensure straps are not in the way of mounts removal.
There are 3 bolts on each mount going into the transmission, as well as one nut holding it to the frame. These bolts may be the worst part of this whole job. Passenger side is not near as cramped as driver side. Passenger side is pictured below. Driver side is the exact same, but with more parts in the way.
A shallow 17mm socket will help a lot if you have one, because there is not much room between the two long bolts and the frame (the solid arrow in the above picture is the position of the long bolt). I ended up grinding my socket down to allow access. A lot of things in the way on the driver side, causing you to only turn the wrench little by little (open ended wrench was all I could fit). Be patient. Once these are out, reward yourself! When reassembling, I did the really long bolts (one on each mount) last since they took the longest and was able to thread them on most of the way by hand, which definitely saved me time.
Now to the bottom. Raise car. Remove under tray. Drain transmission fluid. Remove center exhaust pipe (right behind cat). Remove heat shield. Label position of prop shaft to rear diff and remove prop shaft. Remove front drive axles (I removed LCA ball joint and tie rod, then slid the axles out of transmission); a pry bar did the trick. Use seat belt to hold steering wheel into place.
Label position (if you choose) and remove steering shaft universal joint; pry off after completely removing bolt. Remove lower starter bolt. Feel around for it first, use an extension bar and it's not too bad. Unplug solenoid wire and move starter out of the way. Remove two lower transmission bolts and two nuts.
Remove the bracket on the driver side of the transmission that holds the cables for the gear shifter.
Then, go to the passenger side and remove the gear shift and select cables from transmission; two bolts for each. Also, remove pin for shifter bushing (outside of pic).
I did not completely remove the cables at the shifter because I had plenty of room with them still in place. Make sure not to bend these at a sharp angle. Once removed, double check and make sure everything from the transmission has been removed.
Now is the time to support the weight of the transmission independently from the engine. Put jack in place, ensuring you have adequate space to slide back transmission and lower out of the way. Remove transmission crossmember from vehicle and transmission.
And the fun continues. I pried, chiseled, and pushed/pulled for quite some time before I finally separated the engine and transmission. What finally did it was a hammer and chisel from above. It helped me to secure the engine to the frame with ratchet straps so I could shake and shimmy the transmission without moving the engine around as well (since the rear of engine is floating with straps already, it will want to move). Once I slid them a half inch apart, the rest went smoothly. I backed the transmission up to clear the input shaft, then lowered it and gave myself enough room to work.
On to the easy part. Label or take pic of position of clutch/flywheel in case they need to rotate some for the next step. Unbolt the 6 bolts for the clutch and remove clutch and pressure plate. Unbolt the 8 bolts for the flywheel and remove flywheel. I used a 7/16 inch open ended wrench to keep the flywheel from spinning while I loosened/tightened the bolts.
Clean away all the clutch dust and ensure your rear main seal is not leaking. Fortunately, mine was fine. Get flywheel resurfaced or replace if necessary, and install new pilot bearing. Install in reverse order. Inspect, clean, and grease clutch fork pivot point. Replace TOB.
Make sure to clean clutch and flywheel surfaces with degreaser before installing clutch. When installing, make sure alignment tool slides in and out without much pressure at all. Those plastic ones have some play in them. I used a little high temp grease on the two bottom studs, dowels, and tiny bit on the input shaft to ensure everything went back together smoother than it came out.
The key of reinstalling transmission is the angle of the input shaft. Be patient. Get the first two studs on, then good luck to you. I played around with it quite a bit by raising and lowering the rear of the tranny before I was finally able to wiggle it right into place. Do not be tempted to pull them together with the bolts. Once everything is lined up properly, it should slide right into place. The rest is done in the reverse order of removal.
-Flywheel (8 bolts) 55.8 ft/lbs in star pattern
-Clutch (6 bolts) 11.8 ft/lbs
-Transmission bolts to engine, including starter (6 bolts, 2 nuts) 36.9 ft/lbs
-Transmission/rear engine mounts (3 bolts per side) 55.3 ft/lbs
-Transmission/rear engine mounts (1 nut per side) 33.2 ft/lbs
-Transmission crossmember (front 2 bolts) 103.3 ft/lbs
-Transmission crossmember (rear 4 bolts) 55.3 ft/lbs
-Clutch operating cylinder (2 bolts) 27.3 ft/lbs
-Prop shaft bolts (good luck getting a torque wrench on these)
I'm SURE I missed some things and probably jumbled some things around, since this write-up was a bit of an afterthought. Make sure to really plan ahead if you are going to tackle this. But hope it helps as a reference!