So I spent yesterday replacing the clutch in my 06 WRX, installing Group-N pitch stop and motor mounts and here is my story:
* First and foremost I want to say that this is an involved job. I have a whole host of tools both manual and air powered, a lift, transmission jacks etc, etc; have replaced over a dozen transmissions and clutches and a WRX clutch is one very very involved job. I now fully understand why they charge soo much to do it at a shop. So if you are contemplating replacing the clutch in your wrx and all you have is a basic tool kit and a couple hundred bucks, or like to cut corners, this job is not for you.
* A full set of open end wrenches in metric.
* A full set of ratcheting box end wrenches in metric.
* A full set of Sockets in metric deep reach both 3/8" and 1/2" drive.
* A full set of sockets in metric standard reach 3/8" and 1/2" drive.
* A whole host of ratchet extensions in 1/2" and 3/8"
* T70 torx
* A 1/2" breaker bar.
* A 3/8" breaker bar.
* A 1/2" torque wrench.
* A 3/8" torque wrench.
* Pry bars, bunch of sizes.
* Needle nose pliers.
* Transmission jack or Jack with tranny adapter.
* Various stands.
* Screw drivers etc.
*** 1/2" air impact will save lots of time
The beauty of this job is that shy of the lug nuts you need very few sizes to do the whole job. Pretty much the entire job can be done with the following tool sizes: 8mm, 10mm, 12mm, 14mm, 17mm, 19mm with the only 19mm things being the castles nuts on the ball joint IIRC.
The Parts list:
* Clutch kit (I used Exedy 15804)
* Flywheel (OEM SUBI is what I used)
* Gear oil (5 qts I did the rear end too)
* Cotter pins for the castle nuts (the only thing I forgot and had to go get)
* Can of brake clean
* Synthetic grease
* Down Pipe gasket
* axle seals
* A Good manual
* Beer...for medication
This is a great "while you are there" job. After the transmission is out, and in the process of taking it out, you touch everything. I put in group-n motor mounts and changed the pitch stop to group N while I was there, but I already had changed the shifter bushings and transmission mounts otherwise this would be the opportune time. This is the best time to change the motor mounts because the rear bolt that is usually obstructed by the tranny is fully exposed and you only have to jack up the engine since the transmission is out.
* Motor mounts
* Pitch stop
* Shifter bushings
* All tranny mounts (You have to remove the crossmember from the tranny so you can replace them all on a bench)
* Down pipe and exhaust
* Sway bars and end links
Whats so different about the 06+?
The 2006+ WRX clutch system was swapped from pull to push. What that means within the scope of this job is that there are a couple fewer steps.
* There is no clutch fork release rod you need to take out
* There are no spring pins holding the axles in that need to be punched out
* The clutch kit part #'s are different.
Gettin down and dirty:
I can't stress enough the importance of a good manual, I had the factory Subaru Workshop manual.
Under the hood (Do this first):
* Now the first step is to pop the hood and get the intercooler off.
* Also disconnect the negative cable of the battery (you are taking the starter off afterall).
* Remove the down pipe heatshield.
* Remove the down pipe bolts and nuts you can get too.
* Remove the starter.
* Remove the slave cylinder and zip tie out of the way.
* Undo the 3 electrical connectors up top.
* Undo the top transmission bolts (2 also hold the starter in)
* Undo the pitch stopper
* Undo the stupid little ground cable that bolts next to the pitch stop otherwise you'll have to take it off at the tranny and that sux. (the manual says nothing about this cable)
The manual tells you to take off the throttle body and I dunno why, there is no reason at all. The manual wants you to install a tool in place of the pitch stop, I didn't do that either, I used a jack under the engine.
Now put the car in the air!
I had a lift to use, but doing this job on jackstands would scare me. There are not sufficient safe points to position jack stands under the front IMO, but it can be and has been done in the garage on jackstands many times.
EDIT: Here is a DIY for wooden wheel stands that may help people do this job.
DIY: Wooden Wheel Stands
After you have it up in the air.
* Drain the tranny fluid first! Otherwise it will pour out when you take all 3 driveshafts out. My 06 takes a huge T70 torx bit and a 1/2" breaker bar.
* Take the exhaust off and get it out of the way, don't forget to unclip the 02 sensor.
* Pull the rear driveline cover and pull the driveline. You will need to rotate the shaft by hand and then set the ebrake to break the 4 bolts holding the driveshaft to the rear end.
* disconnect the lower sway bar end links on both sides
* undo the lower castle nuts on the a arms and pull the cotter pins
* pull the hub assembly out of the lower a arm
* pull the axles out of the side of the tranny and try your damndest not to damage the axle seals, move them out of the way.
* Put the tranny jack under the front of the tranny ( not on the crossmember cause this needs to come off)
* remove tranny crossmember (6 bolts) drops as one unit. ( great time to change those tranny mounts we talked about)
* put something under the engine to support it, a floor jack with a block of wood under the oil pan works good
* Undo the remaining tranny bolts from the bottom of the bellhousing and remove.
* With a buddy (if you have one, I did) use a pry bar between the bottom of the tranny and the bottom of the frame. 1 quick pry and the whole thing should pop free.
* roll the tranny out of the way.
* with an impact, remove the pressure plate, clutch disc and flywheel.
Putting it all back in:
Here is where being diligent and a little OCD helps....
There are several little grease points that need to be taken care of.
* You need to pop the shifter fork out of the transmission, Take off the old TOB, clean the fork and lubricate the wear surfaces with a little bit of grease not a ton.
* Clean the fork pivot ball next to the input shaft of the trans and use some grease here too.
* Clean all the old clutch fibers off of everything including the trans with a shop vac.
* Clean the input shaft splines and grease lightly.
* Put the new flywheel onto the crank shaft and torque the bolts. You'll either need a friend with a pry bar or the special tool to do this. I believe the spec was 53ish ft-lbs.
* Spray the friction surface of the flywheel with a little bit of brake clean and wipe with a clean paper towel
* Spray the friction surface of the new pressure plate with some brake clean and wipe with a towel too
* using your clutch alignment tool, install the new clutch disc and pressure plate. Torque bolts to procedure and spec.
-----Just an FYI, you really can't put the clutch disc (in this case) in backwards, it will only go one way.
* Putting the trans in;
IMO this was one of the worst parts of the whole job. It wasn't the hardest one I have ever had to deal with but its not fun. Some pointers:
--Grease the bottom two bellhousing studs on the engine
--Grease the two alignment pins on the bellhousing
--Don't shove the trans into place, spend some time getting the angle of the engine and trans to match
--Once the input shaft is in contact with the splines and not quite going in, grab the rear driveline and insert it into the back of the trans. Rotate it until you feel the splines of the trans and clutch line up (It'll stop rotating), then gingerly wiggle it back into place.
* Now reinstall everything in reverse order
Reinstalling the front axles is the second hardest part of this job. It requires 2 people, a lot of finesse, grunting and shoving to get them to go. All the while you need to make sure not to damage the axle seals.
The torque spec on the bellhousing bolts is 37ft-lbs.
The torque spec on the 2 large front tranny crossmember bolts is 103 ft-lbs.
The torque spec on the 4 rear crossmember bolts is 50ish (maybe 57?) ft-lbs.
The torque spec on the lower castle nut is 36ft-lbs + lining up the cotter pin hole
The pitch stop mount bolts have 2 different torque values.
I like to put a dab of grease on any steel bolt going into aluminum to help combat electrolysis and corrosion.
If there was ever any doubt, the factory clutch disc is made by exedy, I took a pic ill post.
Some pics of my job:
Car in the air:
Trans jack I made and stabilizer stands:
Tons of clutch fibers:
The little fork pivot ball that needs cleaning and grease:
Flywheel and engine side bellhousing, shows the studs to grease and pins to grease to ease reinstallation:
Factory Disc stamped EXEDY on the center ring, middle of two springs: