Clutch Replacement - Part Two
Last Updated: 11/15/2010
- Remove shift boot lever (retaining clip at top )(Be careful of plastic cosmetic items, remove ashtray, two screws, lift center piece slightly & push out leather boot from bottom) set aside.
- Wedge clutch pedal down (need to do this so rear axles will turn with drive-shaft , thus positioning clamping sleeve for removal.)
- Remove large protective cover on transmission bell housing, exposing clamping sleeve
- Position drive shaft (turn rear wheels) and loosen clamping sleeve through opening 2 Allen bolts (8mm hex with extension)
- Mark position of clamping sleeve, slide toward transmission (tap if stuck)
- Unwedge clutch pedal
- Remove transmission fluid ( A good time for this, but not necessary)
- Clean area around where drive axles connect to transmission (this will prevent contamination of CV-Joint grease)
- Disconnect drive shaft axles from transmission and suspend level with wire from shocks
- Cover drive axle ends and transmission flanges with small plastic bags and close (try to keep all CV-Joint grease intact & clean)
- Remove back-up light connection (2 wires) color coded, terminals not keyed.
- Remove speedo cable (be careful of connector when disconnecting)
- Remove speedo housing (threaded) set aside, cover hole on transmission.
- Push back rubber dust cover on shift rod @ end, cut wire and remove shift-rod bolt on selector linkage.
- Remove circlip from shift-lever
- Unbolt shift lever with bearing bracket from central tube (pushing foam aside) use 10mm socket with extension (2 bolts), mark position of pivot flange on central tube, for reassembly.
- While pressing down on foam insulation turn shift rod over, and push selector rod forward in cavity about 300mm (12") This will move shift rod out of transmission protective tube.
- NOTE: Try not to damage insulation foam sheet!
- Move black protective tube for shift rod back toward rear of car. (not necessary) I tried to do this as described in the 944 Workshop Manual Vol.11 p.30-07 but was unsuccessful. The tube came out easily when I removed the transmission.
- NOTE: According to the Workshop Manual if the retainers on the tube become damaged during this process, the tube should be replaced.
- Put wooden block between central tube and rear suspension cross member. (This keeps stress off the torque when transmission is removed, keeping torque tube level.
- Run in hydraulic jack under transmission and support
- NOTE: Center of gravity is more towards rear of transmission.. Have an assistant help with this procedure, it helps.
- Remove housing bolts (4) These bolts are not all the same length, make sure they are labeled. NOTE: I had trouble with the top driver's side Allen bolt. I didn't have enough clearance for a hex socket (10mm). I took the hex bit out of the socket and used a wrench on the bit. Not fun! Good luck!
- Remove transmission suspension mounting bolts at top of transmission.(2) (make sure jack is supporting trans. This will keep the suspension bolts from binding in shaft.
- With an assistant stabilizing transmission on jack cup lower transmission slowly down while clearing spare tire well. Readjust position on cup if necessary. Observe protective tube for damage and separation from housing.
- NOTE: If your transmission is equipped with oil cooler treat it them with care, they damage easily. Once transmission is clear pull jack towards rear, while watching hanging axles for clearance.
- Remove Transverse axle strut between body and axle (4 bolts)
- Remove fuel filter hose clamp (Let fuel filter hang)
- Remove transmission carrier(4 bolts) NOTE: Check out Silent-Bloc Mount for damage and stress. Usually they last quite a long time. Replace if damaged. An expensive part.($150.00) Approx.
- Remove clutch slave cylinder and hang out of way (2 bolts)
- Mark position of exhaust carriers on central tube, and slacken but don't remove.
- Put jack under oil pan with a piece of wood between jack cup and grilled oil pan.
- NOTE: This is to prevent engine from settling to far at rear once bell housing and central are removed.
- Unbolt 4 bolts from central tube to clutch bell housing
- Slide central tube rearward with selector rod after rotating 90 degrees (be careful not to damage brake lines when rotating central tube)
- NOTE: Wear leather gloves when handling transaxle to avoid injuries. Note position of catch hooks. Exhaust clamps should be free to slide as needed)
- Remove temporary support block for central tube at rear of car
- Loosen release lever shaft retaining bolt.
- Thread 8mm * 150mm bolt into release lever shaft on clutch bell housing; with Vice-Grips attached to end of bolt, tap Grips with hammer to remove shaft. NOTE: A shorter bolt can be used, but I needed the extra leverage to remove shaft. (REFER to Haynes Manual Chapter 8 p.136)
- Remove bell housing bolts (4) total 2 @ top, 2 @ bottom NOTE: The bolts at the top are a little difficult to access. Use a long flex head ratchet (Use 17mm or 19mm ? 12 point socket.)
- Remove bell housing with release lever.
- With 8 mm 12 point driver, remove 9 cheese head bolts. Uniformly loosen bolts on pressure plate.
- NOTE: Use a HIGH QUALITY 12 point tool! Make sure tool is seated properly in head, and that pressure is applied when turning out bolt, this may help from stripping out the head. ( the head of these cheese heads are real easy to strip out!!)
- Remove pressure plate with release bearing and clutch Disc (Be careful the pressure plate is somewhat heavy)
- Remove starter ring from pressure plate ( I used a hammer and a block of wood. Spray with penetrating spray. Remove evenly as not to bend ring.
- NOTE: The release bearing and pressure plate are packaged separately, therefore you must assemble these as one working part.
- Install release bearing on pressure plate ( have an assistant push down on pressure plate while you install retaining ring. NOTE: compare assembly of old unit.
- Install starter ring on new pressure plate ( align bolt holes and tap on evenly)
- NOTE: This is a very precise fit make sure ring goes on even and bolt holes are exactly aligned.
- The pilot bearing is a bearing that supports the rear of the crankshaft. As you can see it has taken a lot of work to get to this point, therefore it is a good idea that this part be replaced.
- Removal requires the use of a special hooked puller tool, but this method should work fine.
- Find a 8" bolt with a head that is slightly smaller then the bearing opening. Attach Vice-Grips to other end. Hook head on other side of bearing, and lightly tap on pliers with a hammer.
- NOTE: A long bolt will give you more leverage. I had a little trouble with this. HINT: Tap out evenly. ( refer to Haynes Manual Chapter 8 p.140 )
- Remove bearing and clean out bore in the crankshaft recess
- Lightly oil sides of new pilot bearing and install (use a suitable size socket with extension and hammer NOTE: Make sure bearing is tapped in evenly!
- Remove bolts (M6) holding guide sleeve on clutch bell housing ; replace with new part if damaged or worn ( torque=11 ft. lbs. / 15Nm )
- Punch out old needle bearings ( 2 ) with proper size socket and extension.
- NOTE: Spray the needle bearing bore area with a penetrating spray to aid in removal.
- NOTE: These were tough, I used a block of wood under the lever, with the extension going through the opposite needle bearing shaft. I would have used a vice , but did not have one at the time.
- Oil sides of bearings and install, and make sure they punch in level. A very tight fit.
- Check flywheel for wear and scoring (Heat checking). If imperfections are slight, a machine shop can machine the surface to spec.
- Make sure all clutch surface areas are free of grease and oil. It is important that friction surfaces are perfectly clean.
- Apply a thin coat of MoS2 grease to guide sleeve, splines of central shaft, and grooved ball bearing/flywheel area.
- Lubricate release lever fork (needle sleeves, ball socket, and fork)
- NOTE: Solid white lubricating paste # AOS 126 0006 is no longer used, because it hardens with age, replace with MoS2.
- Use clutch alignment tool to center clutch plate to pressure plate
- NOTE: Make sure tool is inserted all the way into pilot bearing.
- Apply a small amount of anti-seize to threads of cheese head bolts, and start by hand to assure that the threads won't be stripped. Tighten uniformly in a diagonally opposite sequence ( 18 ft. lbs. /25Nm ).
- NOTE: Make sure you have a good leverage and that the tool is in level, these bolt heads are real shallow. Turn flywheel to access bolts at bottom for best results. (takes some effort)
- UPDATE!!! Installation procedure for updated speed sensor mounting block turbo 1989- The installation of the speed sensor mounting block is straight forward. However, there is a height adjustment. One of the bolt holes in the sensor is elliptical. The mounting block height can be adjusted by rotation the block around the other bolt. The height adjustment is very important. I installed the block too low, and as a result, one of the two sensors (speed or reference, I don't know which is which) got destroyed by the pin on the flywheel. If you start the car and hear a tapping sound, once per revolution, check to make sure that the sensors are NOT too low.
- Install the release lever and clutch housing together on the engine release bearing, with cup on release lever facing slave cylinder opening. Two forks at end will fit under release bearing edge. Hold lever through slave cylinder opening while aligning.( you will understand this better when you do it ).
- NOTE: Make sure that the bonded bolt on the flywheel is facing down. This will prevent damage to the reference transmitters.
- Tighten clutch housing bolts M 12 (4) two different lengths! torque= (54ft. lbs. /75 Nm )
- NOTE: Hand tighten these blots (this is important especially when threading into an alloy material. Starting this bolts with a socket will increase the chance of cross threading ( Use anti-seize on threads )
- Move release lever so that needle sleeves are aligned with bore in clutch housing.
- Slide in release lever shaft so that milled face is toward securing bolt.
- Slide in all the way ( it helps to lubricate shaft). You may need to move release lever back and forth for proper alignment. Never force! Install securing bolt with back up hex nut when shaft is correctly positioned. torque= 7 ft. lbs. / 9.5 Nm )
- Install rubber seal on clutch inspection hole , if missing.
- HINT : Apply a small amount of silicone to plug sides, and you won't have to replace it again.
**** The sequence for assembly of central tube, transmission, exhaust system, etc... is the reverse of removal, with some notes below. ****
- Slide by-pass valve bracket on central tube to marked position and tighten
- Position by-pass valve (waste gate) between clutch housing and body.
- Uniformly tighten M 6 bolts connecting bypass line/ exhaust cross-pipe, torque to spec. torque= 7ft. lbs /10 Nm (sorry this is a bit vague)
- NOTE: Always use new seal rings (packing rings) on exhaust system!
- When all exhaust system bolts have been inserted, tighten the flange connection between the turbo charger and exhaust system first.
- NOTE: torque specs. exhaust bolts (Pay attention to different size bolts!!) M 8 bolts 14 + 1.4 ft. lbs. /20 + 2 Nm, M 10 bolts 29 + 3.6 ft. lbs. /40 + 5 Nm
- Run car and check exhaust system for leaks.
- Once exhaust system has cooled down, retighten all bolts and nuts to specified torque (see above)
- NOTE: It is very important to retighten the flange connection between the by-pass line and exhaust cross-pipe. Refer to Workshop Manual "Turbo supplement" p. 30-7 # 6.
- NOTE: When installing heat shields and guards, make sure they are solid and free from vibration. (i.e. center catalytic converter shield)
- NOTE: If insulation sheet foam was damaged when shift rod was moved, replace or repair if possible.
INTAKE MANIFOLD :
- Assembly is reverse of disassembly, with some notes provided below.
- Install master cylinder guard with car still on stands (this way it will be easier to access bottom 2 nuts)
- NOTE: There is an electrical harness that runs along the front edge of this guard. Make sure that the guard is not binding on this cable bundle, this will make alignment almost impossible. I slid the turbo pump bracket for more clearance. You can also loosen turbo pump on bracket, but be careful not to stress the bottom water pump hoses. This can cause the motor shaft to bind resulting in a inoperative pump. This happened to me. I was about to order a new unit, but remembered that Jim Selders previously posted this same problem on the P-files. All I did was loosen the clamp on the bracket and moved the pump down, It worked ! Thanks Jim
- This pump has been updated to a more robust design, and I imagine this problem was resolved.
- Make sure that that the ( 4 ) intake manifold gaskets are replaced if the manifold is removed.
- NOTE: I would recommend using a gasket removing solvent to remove gaskets. (i.e. Wurth Gasket remover # 89091000) I wish I had used this !
- When installing intercooler lines and tubes, connect all lines first then tighten clamps. (make sure clamp below throttle housing does not obstruct the movement of the throttle cam)
- Check out your air filter, replace if needed.
- Inspect all fuel injector seals and O-rings. Replace if cracked or damaged.
- NOTE: Inspect the seal around the injector needles for hairline cracks.
- Make sure all spark plug wires are routed and laced properly, and inspect condition.
TORQUE SPECS: (Not previously mentioned)
- Reference mark and speed sensors= 6 ft. lbs. / 8 Nm
- Slave cylinder to clutch housing= 15 ft. lbs. / 21 Nm
- Central tube flange to clutch housing= 30 ft. lbs. / 42 Nm
- Starter to clutch housing= ?
- Transmission carrier to body= 34 ft. lbs. / 46 Nm
- Bracket to transmission= 17 ft. lbs. / 23 Nm
- Drive shaft to transmission input shaft= 58 ft. lbs. / 80 Nm (guide sleeve)
- Shift rod to transmission= 15 ft. lbs. / 21 Nm
- Shift lever plate to central tube= 15 ft. lbs. / 21 Nm
- Drive axles to transmission= 30 ft. lbs. / 41 Nm
- Speedometer socket to transmission= 30 ft. lbs. / 42 Nm ( ? )
- Intake manifold to engine= 14 ft. lbs. / 20 Nm
- Oxygen Sensor= 36-43 ft. lbs. / 50-60 Nm
- ALL OTHER BOLTS:
- M 6 = (6 + 1.4 ft, lbs.) 8 + 2 Nm
- M 8 = (14 + 1.4 ft. lbs.) 20 + 2 Nm
- M 10 = (29 + 3.6 ft. lbs.) 40 + 5 Nm
Update Notes: Revised 04.09.01 MK
- ( drive shaft clamping sleeve removal technique update)
- ( reference sensors mounting block removal/installation update)
- ( Added Paragon Products Inc. -parts vendor-)
- ( Added "Turbo Cup" clutch disc to parts list with additional notes)
Credits: Mike Kehr
Paragon Notes: The 924S, 944, 944S and 944S2 each featured a rubber centered clutch disc from the factory. Generally, when the clutch fails, it won't be because the disc ran out of friction material, but rather that the rubber center deteriorated and fell apart. Our kits feature a Sachs spring center disc made SPECIFICALLY for the 944. Doing a clutch on a 944 isn't a fun job, take the steps to make sure it isn't a frequent job too! Kits include Sachs pressure plate, disc and throw-out bearing.
The 944 Turbo featured a spring centered clutch disc from the factory that in addition to the large springs near the friction material, also had 6 small springs near the center of the disc. Generally, when the clutch fails, it won't be because the disc ran out of friction material, but rather because one or more of the small dampening springs fell out. Our kits feature a Sachs spring center disc made SPECIFICALLY for the 944 Turbo. This disc does NOT include the 6 small dampening springs and is often referred to as the "Cup" or "HD" disc. Doing a clutch on a 944 isn't a fun job, take the steps to make sure it isn't a frequent job too! Kits include Sachs pressure plate, disc and throw-out bearing. You can also build your clutch package utilizing our Lightweight Racing Pressure Plate.When doing a clutch job, it's always a good idea to check your flywheel to see if it needs to be replaced. Thin flywheels can warp and cause shuddering of your brand new clutch setup. If in doubt, don't take a chance!
When it's time to replace the clutch on your 968, only use the OEM Sachs parts that we include in our kits. Clutch kits include pressure plate, disc and throw out bearing. 968 Sport Clutch packages feature a special pressure plate that has 3100-3300 lbs. of clamping force whereas the stock pressure plate has 2300-2500 lbs. of clamping force.
> Window Express Kit Installation
> AC Delete
> Accusump Installation
> Adjustable Ride Height Kit - Paragon
> Alternator Replacement
> Brakes, front - 924S, 944, 944S
> Brey-Krause Strut Brace Installation - 944
> Camber Plate Installation (Paragon)
> Clock/Bulb Replacement, digital, Late 944 and 968
> Clutch Replacement - Part One
> Clutch Slave Bleeder Valve Remote
> Control Arm Bushing Upgrade - Weltmeister
> Control Arm, Front - Info
> Coolant Flush
> DME Chip Installation
> Dash Replacement
> Engine Identification
> Engine Production
> Fuel Level Sender
> KLA Strut Brace Installation - 924S, 944, 968
> Koni Strut Conversion - 8641-1414S for late 944, 968
> Motor Mount Replacement
> Odometer Gear Replacement - late 944
> Oil Cooling, Auxiliary
> Oil Pressure Relief Valve
> Oil Pressure Sending Unit Replacement
> Rear Ride Height Adjustment
> Porsche Chronology
> Rear Spring Rates vs. Effective Rates
> Rear Wheel Bearing Diagnosis
> Rear Wheel Bearing Replacement - 924, early 944
> Rear Wheel Bearing Replacement - late 944, 968
> Ride Height Measurement
> Rod Bearing Replacement
> Shift Lever Rebuild
> Short Shift Kit
> Throttle Position Sensor
> Sway Bars - Info
> Torque Tube Rebuild
> Torsion Bar Replacement
> Transaxle Fluid - Info
> Transaxle Fluid Change
> Rear Sway Bar Installation
> Transaxle Replacement
> Heater Clip
> Window Regulator Replacement