Join Date: Aug 2011
Location: Dallas, TX
2006 WRX Wagon
2004 WRX Wagon
2006 WRX Clutch Replacement - a guide / retrospective
>>PRETTY GOOGLE DOCS VERSION<<
I recently replaced the clutch in my 2006 WRX Wagon. I found several guides around the interwebs that i used, as well as the FSM, but it struck me that i found nothing particularly useful from NASIOC during my searches. Hopefully this proves to be useful for someone in the future.
Like any technical anecdote, i have a few caveats.
What you will need:
- This was my first time replacing a clutch, dropping a transmission, etc so i was likely much more cautious/slow then more seasoned mechanics.
- I donít have a lot of pictures- i was doing this with the help of a friend and we pretty much just plowed forward.
- I was missing a couple tools that would have made this job a lot easier, namely a pickle fork and proper transmission jack.
- This guide will be the ďdrop the transĒ method. In retrospect, if you have an engine hoist, just pull the dang motor. It will take you much less time to do this job like that.
- a loving and understanding significant other (Alternatively, no significant other)
- a trusty buddy
- 3/8Ē socket sets. I used pretty much everything from 10mm to 22mm, deep and shallow
- a couple 3/8Ē ratchets so you can tag team things
- A big 1/2Ē breaker bar. Not totally necessary, but a breaker bar is like a multitool.
- did i mention a 22mm socket? this is to put on the crank pulley and hold it in place while you break the flywheel bolts loose.
- anti seize
- high-temp, super duper multipurpose grease. I like Green Grease.
- Brake Cleaner
- Penetrating Oil (i used about one entire can)
- Trans fluid of your choosing
- Axle seals (just buy them. trust me. Itís $14 and itís not worth smashing one up and not having spares.)
- buttload of paper towel.
- A creeper makes this much easier
- a good jack (or 2) and a TALL set of jackstands. For reference, the absolute minimum height the car can be at to remove the trans from underneath is the minimum height of a harbor freight 6 ton jackstand.
- Torque wrench. If youíve been putting it off, go buy one. Itís a good investment and i would not do this job without it.
- a way to keep all your hardware organized. i used a bunch of yogurt cups.
- Patience, confidence, an abundance of caution, and some inherent mechanical aptitude.
Other guides have broken this up into ďon the groundĒ and ďIn the airĒ and i like this approach, so i will flatter them by mimicking it.
On the ground:
- iím not one to cut corners but i am one to ask, ďDoes this really need to come out?Ē So if itís listed here, it really needs to come out in my opinion)
- Read all the steps before you begin, and go ahead and spray every bolt you can get to that needs to be removed. Ideally you do this 3 or 4 times in the 24 hour period before you start)
In the air:
- Open beer, set aside
- Remove battery
- Remove Intercooler
- Remove passenger side intercooler bracket
- I sheared off one of the bracket bolts. It was just not going to come out. Use caution
- Remove turbo heatshield
- Remove Visible turbo to downpipe nuts and bolts
- remove clutch slave cylinder from trans case, set out of the way. You donít need to remove the clutch line
- Remove top 2 transmission case bolts. One sits next to the turbo and one goes through the upper starter mount hole. I think these are the only two you can easily get to from up top. Note that these two are the LONGER case bolts.
- Remove pitch stop
- Remove all the electrical connections to the transmission.
- There are 3 or 4 plugs that sit under the pitch stop
- donít forget the little ground wire on the firewall next to the pitch stop
- I think thatís all
- Get that mother trucker up as high as you can on jackstands. Your NAPA AC Delco 1.5 ton jack stands are not going to cut it. I used Kobalt 3 ton and Harbor Freight 6 ton stands. Make SURE youíre confident with your jackstand placement. Youíre going to be shaking and pushing and shoving the car all over the place.
- Get the exhaust out of the way. Remove the downpipe and midpipe. Remember to disconnect the rear O2 and wideband (if applicable) before trying to pull the downpipe.
- Drain the trans. 06 is the infamous gigantor torx bit.
- While the trans is draining, undo the 6 14mm bolts of the driveshaft cover just in front of the rear diff.
- Break the 14mm trans carrier bearing bolts loose but donít remove them yet
- Remove the 4 12mm bolts holding the driveshaft to the diff
- You will need to apply the handbrake and rotate the shaft in intervals to get to the bolts
- when the driveshaft is free from the diff, hold it roughly in place while you drop the bolts out of the carrier bearing.
- with all the shaft mounting points free, carefully slide the driveshaft directly back towards the diff and it will slide out of the tail of the transmission.
- Put the drainplug back into the trans if its done draining.
- Since youíre probably out from under your car to set the driveshaft somewhere, lets do some work out here.
- Take your front wheels off
- Take the hubs apart
- Remove both the 17mm bolts holding the strut to the hub
- remove both the 12mm bolts holding the brake and abs lines to the hub
- disconnect the endlinks, either from the bar or the control arm
- remove the 14mm bolt in the collar that holds the ball joint into the hub
- this may vary by model (wagon/sedan). The sedan has aluminum control arms and i think the mounting style is different. In the wagon, i could not remove the ball joint stud from the arm, i had to remove the ball joint from the hub. Which was an enormous pain.
- Did i mention this was a pain? Apply copious amounts of penetrating oil to the collar bolt and go chug a beer.
- Carefully start to back these bolts out of the ball joint collars. They are not big bolts, but they have an enormous amount of tension on them and are likely very rusty.
- Remove the ball joints from the hubs.
- A pickle fork is the appropriate tool for this, which did not have.
- a pickle fork, while the right tool, will likely destroy the boots.
- One side of the car i was able to wedge my breaker bar handle between the control arm and the hub and the ball joint popped right out.
- The other side required almost 3 hours of various attempts at mechanical advantage.
- Eventually we discovered that trying to hammer all manner of objects between the control arm and the hub was causing the collar to squeeze the ball joint. By placing the breaker bar handle end on only one half of the collar and hammering viciously with a deadblow, it sloooowly started to come free of the hub.
- This ball joint, for whatever reason, was horrifically rusted. Actually most of the rust was probably from the hub, but i spent another two hours later cleaning up both ball joints and hub sockets, and apply anti seize.
- The control arm bushings apply a lot of upward force on the arms. You will not get the control arms to hang free of the hubs.
- At this point the only things holding the hubs in place are the tie rods and the axles.
- Now that youíre violently frustrated, lets get back under the car.
- Remove the remaining transmission case bolts
- There is one more holding the starter on, and i believe 4 more around the bell housing. Two are studs with nuts. Theyíre pretty obvious.
- remove the starter. It should just drop free from the trans, but you will need a 12mm socket to remove the positive battery connection on the back. The black ground clip should just slide off
- Using either another jack, jackstand, appropriately sized 2x4, petrified dinosaur fossil, etc, apply tension to the crosspipe between the headers. The reason for this is that when you break the trans free, the motor is going to want to flop forward. This probably wonít damage anything, but it will make it nearly impossible to get the trans lined back up later. We want the motor to basically stay in a neutral, upright position.
- Position a jack under the trans just aft of the drain plug, and lift it to meet the trans. No pressure on the trans is needed.
- Remove the 4 14mm bolts holding the transmission mount to the transmission
- remove the 4 14mm bolts holding the rear section of the cross member to the frame
- remove the 2 17mm bolts holding the front section of the cross member to the frame.
- Set crossmember in the parts bin for now.
- Disconnect the upper shift linkage (the two cylinders welded together) and the front shift bushing (the thing stuck onto the rod on the transmission)
- Ziptie the linkages together and just let them hang there.
- remove the downpipe bracket from the rear of the trans case. this gets in the way
- Time to pop the axles out. On the 06+ WRX, this is almost a trivial task. Find something you can wedge between the CV cup (green thing) and the trans. A big screwdriver will work.
- Lever the axle away from the trans. with a bit of force, it will pop free. DO NOT REMOVE FROM TRANS YET. it wonít work.
- Now you need a buddy on the hub to give you some extra clearance.
- Turn the steering wheel in the direction of the side youíre removing to extend the tie rod.
- Press the control arm down and out of the way while you lift the hub clear of the ball joint.
- While your buddy pulls the hub away from the car, CAREFULLY guide the axle out of the transmission. Weíre trying not to damage the axle seals here. But if you do, you have spares, right?
- Tie the axle up somewhere out of the way. Pulling them up into the engine bay made the most sense to us. Youíll need to secure them up there with bungies or something.
- Repeat on other side.
- Do a clearance check. At this point, there should be nothing holding the block to the trans except for the super glue that is years of road grime and heat.
- Removing the trans
- Thereís not really a right way to do this, so hereís how i did it.
- Get a very sharp flathead or putty knife and start hammering it in between the block and the case from the top. Gently. We just want to see the smallest gap form here.
- When you see a gap, get back underneath and with your buddy, start wiggling the trans all around while varying the pressure on the jack.
- you may need to get back up on top and do some more levering.
- Eventually the transmission will start to slide off the dowel pins and off the long studs in the block. Supporting the weight on the jack, start to roll the jack back while lowering in small increments. Make sure the input shaft is free of the clutch assembly before you lower the transmission.
- If youíd like, you can keep the trans under the car. I was still waiting on a clutch so i pulled it out for a better look.
- Prepping the trans for reinstall and replacing the clutch
- Since weíre tired of screwing with the trans, letís tackle the clutch. If youíre not in a hurry, it might be a good time to take a break and grab some beers/a sammich.
- The clutch sits under the pressure plate, which is held on with 6 12mm bolts. They have a low torque spec, so knock those suckers out. Be careful because the clutch and (very heavy) pressure plate could fall out on their own.
- Now remove the flywheel. 6 more 12mm bolts, but you will need to hold the crank pulley in place. Using your 22mm socket, and screwdriver and a breaker bar, block the rotation of the crank, clockwise if looking at the front of the car. Wedge the screwdriver into the adjustment channel on the alternator bracket so that the breaker bar will hit it when it rotates, and seat the 22mm socket on the breaker bar into the 22mm nut inside the crank pulley. Itís hard to actually see, so youíll have to feel. Lethal has good pictures of this in his guide on scoobymods. http://www.scoobymods.com/showthread...wrx-12071.html
- Youíll have to walk the flywheel off the crank, but itís HEAVY so be ready.
- Do whatever youíre going to do with the flywheel. replace, resurface, etc. If reusing, pop the old pilot bearing out with a big socket and a solid whack from a deadblow.
- You need to press the new pilot bearing into it. I did this with a 22mm socket, press in from the back (friction surface) side of the pressure plate, make sure itís square, and should be flush with the face of the flywheel. make sure the center does not bind once itís in. The center of the pilot bearing should be lightly greased.
- Get the flywheel back onto the block. Switch the orientation of your screwdriver/breaker bar setup so you can tighten the bolts.
- Thread them in by hand, then torque them in a star pattern to ~52.8 ft lbs.
- Thread your clutch alignment tool into the new clutch, then into the pilot bearing in the flywheel. Make sure the clutch is snug against the flywheel and not drooping on the alignment tool.
- Seat the pressure plate on the clutch and thread in the pressure plate bolts. Keep checking to make sure the clutch is pressed against the flywheel so it stays as centered on the pressure plate and flywheel as possible.
- Torque the the pressure plate bolts in a star pattern to 11.8 ft lbs. This will take a couple minutes, and youíll see the fingers of the pressure plate turn in as you tighten the plate against the clutch.
- Pull the clutch alignment tool out.
- Give it 30 minutes and come back and check the tq on the pressure plate bolts again. Youíre pulling against two springs here (lock washer and pressure plate) so they might settle a bit after your initial torquing. better safe than sorry.
- Now onto the trans. push the tab of the fork towards the back of the trans and it should pop the TOB off the snout. Get rid of that nasty old thing, and bust out the brake cleaner.
- The bell housing is probably pretty grimey so give everything a really thorough cleaning. You can remove the fork by pulling up to release the pivot knob from the spring inside the fork.
- input shaft
- fork pivot dimple
- pretty much all the friction surfaces of your new TOB. Exedy instructions say to even grease the inner race that contacts the pressure plate tines.
- Reassemble the TOB and fork assembly and actuate the fork tab to check for smooth operation.
- If you messed up an axle seal, replace it now.
- Woohoo! time to put it back together.
- By whatever means necessary, get the trans repositioned on a jack, under the car, ready to lift into position behind the block.
- BIG NOTE HERE:
- DO NOT use the transmission case bolts to draw the input shaft into the crank. This is a big no-no because if youíre misaligned, you can crush the pilot bearing/bend the clutch/start a nuclear holocaust.
- Raise the trans into position and get it threaded over the two big case studs towards the bottom.
- Slide it as far forward as you can like this, wiggling and trying to keep the gap around the block and the case even. Either it will go pretty much all the way, or it will stop because the splines of the crank and input shaft are not lining up.
- To make sure everything is aligned, go ahead and start getting the driveshaft back into position. We set the tail end on a jackstand under the diff and slid the nose into the output shaft of the transmission.
- Turn the driveshaft in small increments while you continue to wiggle the transmission into place. It wonít be easy, but it should continue to move a little at a time.
- When you can, go ahead and get the nuts on those two bottom studs, just a little bit. This will keep one of them from slipping off as you wiggle back and forth. Note that if you drop the trans, you're going to snap those studs. Go slowly, be careful.
- When youíve got about a half inch gap left, youíre pretty much good to go. Out of an abundance of caution, we were able to close the gap almost all the way by hand.
- Get all your case bolts back in there except for the starter (because that axle will probably be in the way) and tq them to ~37 ft lb
- The only tricky part left is getting the axles in. Get your buddy in position on the hub again, and lift it up and out to give you plenty of room to guide the axle in. Watch the seals, man. The axle will go in until thereís about 1 inch left, then it will stop. Your buddy needs to give it a REALLY good shove and it should snap all the way home.
From here on itís just putting things back together in reverse order.
Some other notes:
- When you have the slave cylinder back in, itís probably a good idea to check the operation of the clutch.
- Make sure you can turn the driveshaft independent of the motor with the clutch in or the trans in neutral.
- Double check pretty much everything. faster to do it now than when it starts to fall apart later.
- Grease, antiseize everything you touch, and torque to proper spec where it makes sense. If youíre going to be tackling maintenance yourself, these steps will give you some peace of mind, prevent rust, and make life a lot easier when you have to take something apart in the future.
Hope someone finds this useful. You veterans let me know if i missed anything big. I'll work on adding some pictures in the coming days.