The following account explains in detail the procedure of changing a clutch in a 944/951. It also contains a list of tools, chemicals, parts and the sources where to find them. There is a lot of helpful information here for the beginner/novice mechanic.
I have just finished a complete clutch job on my 86' 951, which included replacing the throw out bearing, pressure plate, clutch disc, pilot bearing, guide sleeve, and the two needle bearings on the release lever. I am posting my experiences so I may help others who are mechanically inclined but cannot afford the $1,400.00 + labor to do the job.
This procedure applies to all 944 series cars, with some exceptions.
Porsche sets the shop time @ 23 hours (single cross-pipe) @ $55.00 =$ 1265.00 or ~16 hours (two part cross-pipe) @ $ 55.00=$ 880.00
Refuted 944 know-it-all, George Beuselinck, claims these realistic labor times:
- 944 NA, 8-9 hours.
- 944 Turbo, single piece crossover pipe, 22-24 hours
- 944 Turbo, two piece crossover pipe, 13-18 hours
- 944S and 944S2, 8-9 hours
I completed the entire job in 2 weeks working part time, which included replacing the right motor mount, cleaning underbody and transmission, undercoating, and eliminating all corrosion. Some steps will be frustrating if you have never done this kind of work on this type of car. Take your time, keep organized, and most important have "PATIENCE YOU'LL NEED IT !"
I would like to thank fellow list member Mark Sundt for all his help and support throughout this job. His patience and insight are greatly appreciated. Also I would like to thank, Milo Dorr, Steve Timmons, Kevin Gross, Jim Selders and Doug Dyakar. Without the help of these people I would never have been able to do this job. Thanks to Stan and his informative Archives.
The job should not be undertaken by those without some mechanical ability. It is not an extremely difficult job, but requires many steps especially if your car still has the single part cross pipe. Organization is important! Safety is also VERY important, when working under a car supported by jack stands. Take time and care when raising the car with the hydraulic jack, utilizing the proper jack points. A good idea would be a secondary means of support, such as concrete blocks under the wheels.
I am going to explain this procedure in detail in hopes that I can help other list members do this job. Reviewing and researching before you start is a good way to familiarize yourself with the car, and will make you more confident, resulting in a successful job. The clutch replacement on my 951' was the second time I have ever worked on a car, (other then basic maintenance of course) the first being the replacement of the front struts and strut bearings.
I am going to list tools needed and where to find them. Part #'s will be given, along with chemicals needed, research material sources and torque specs. I will refer to the Haynes 944 manual, the 944 Workshop Manuals( 6 volumes) including the Turbo supplement and Mark Sundt's notes, used with his permission. I have also included HINTS and NOTE sections to point out important areas.
I tried to make this information as accurate as possible. If there are other suggestions or hints that will make this account more complete feel free to add your comments to the list.
GOOD LUCK ! - Mike Kehr
Having the proper tools when working on a Porsche is very important!! Using good quality tools is also very important!! I have found out the hard way!! I was frustrated more times then I can remember while doing this job!! Now AFTER the job is complete I know what tools I should have used, and now you will know BEFORE you start. Of course not all tools listed are mandatory, the variety listed will make life easier.
I have found that most Craftsman tools are very poor in quality. The sockets and wrenches work ok, but the ratchets and mechanical tools are sub-standard in quality. I speak about the "newer" tools, I know that the older product is much better. Hazett and Heyco are the German tools used to assemble German cars, they are very good and are made to fit in some of those tight places. Snap On, Mac, Matco, S&K/Facom are good tools especially Snap On( great quality and big bucks ). There are very few "special" tools required to do this job. A somewhat complete list of tools and the resources for them will follow.
- 1/4" straight
- 1/4" flex head (Snap On)
- 3/8" straight
- 3/8" flex head (long handle) Clutch housing bolts (I used Craftsman)
- 1/2" straight
- breaker bar (for that real stubborn rusted hardware)
- 1/4" 3/8" 1/2"
- 1/4" long medium short (approx.) 3" 6" 12" 18"
- 3/8" long medium short
- 1/4" flexible (i.e. Snap On)
- 3/8" flexible "" ""
- 1/4" Set W/ 13mm, 15mm semi-deep
- 1/4" universal sockets 10mm, 13mm, 15mm
- 1/4 Magnetic 10mm, 13mm
- 3/8" set W/10mm, 13mm, 15mm, 17mm, 19mm semi-deep
- 3/8" universal sockets 13mm, 15mm, 17mm, 19mm
- 1/2" 13mm, 15mm, 17mm, 19mm
- Combination standard length: 8mm, 10mm, 13mm, 14mm, 15mm, 17mm, 19mm
- Box long: 8mm, 10mm, 13/15mm, 17/19mm
- Flare nut crows foot (Snap On): 13mm, 15mm
- Torque Wrench flex head 3/8" (5-75 ft. lbs.) i.e. (Snap On # QJFR275E)
- 3/8" Hex 6mm, 8mm,10mm,12mm (avoid the Craftsman, bits come out of sockets because they are held in poorly. Get the kind that are held in with a pin or set screw. (Hazett)
- 3/8" 12 Point 8mm (for cheese head bolts, hold on pressure plate, drive axles) DON'T CHEAP OUT ON THIS TOOL!! Buy either the Hazett/Heyco or Snap On. @ $ 18.00 it is well worth it! Snap On calls this tool "Triple Square" The flywheel is secured with 12mm cheese heads.
- Clutch alignment tool
- 8mm * 150mm bolt ( for removing release lever shaft) (pilot bearing)
- Vice Grips 10"
- Hammer (not so special)
- Magnetic Pick-up (for that hardware you thought you would never see again)
- Rubber Mallet (Maybe needed for intake manifold removal)
- Safety glasses or goggles
- Various Screwdrivers straight blade , Phillips #1, #2
- Jack stands 3 ton (4 ea.) heavy-duty (12" minimum 17" max. approx.)
- Hydraulic Jack 2 1/4 ton @ least (Min. height 5" inches, maximum height 18" @ least) Blocks of wood & short 2 * 4's
- * Odd Socket Sizes & wrenches 10mm, 13mm, 15mm, 17mm, 19mm are used 95% of the time. I don't think I ever used any even sizes. Maybe 14mm on exhaust system?* Flex Head Ratchets are very useful , don't overlook these tools.
- * Universals and flex sockets for those weird angles
- * 12 point sockets and fine tooth ratchets are a great help in confined areas.
- * Magnetic 1/4"socket 10mm and 13mm is very handy along with a flexible extension and or universal when working in the tight engine compartment spaces.
- * I accomplished the work with much less, but this is what I recommend after completing the job. That is if you have the $$$.
CHEMICALS & GREASE:
- Hi pressure grease MoS2
- Penetrating Spray ( Wurth Rost Off or PB)
- Anti-Seize Compound (i.e. Loctite_37564)
- Wurth HSS-K (Great spray grease)
- Loctite #270 (for M8*25mm ground stud. (clutch bell housing)
- Wurth Green Bushing/Bearing fixing Agent (optional)
- Gasket remover (i.e. Wurth # 89091000)
- 944 Parts Fiche: ( not necessary but helps to identify parts , for PSM 000.002 ordering, disassembly / assembly.)
- Haynes 944 Manual: #1027 chapter 7 "Manual Transaxle" pp.126-129 chapter 8 "Clutch and Drive train pp.134-140
- Porsche 944 Workshop Manual: (Vol.#2 Transmission) #WKD 481.821 USA 30-05/30-09 Torque specs (6 vol.) 30-5/30-17 Clutch 34-1/34-5 Transmission
- Porsche 944 Turbo Supplement: 30-1/30-7, 30-05/30-09 Clutch 21-6, 24-4 Intake Manifold
- Porschephiles archives: Dec 91, Mar.92 April, May 94
A NOTE ON REFERENCE MATERIAL:
I would at least purchase the HAYNES MANUAL. I would suggest having access to a friends set of workshop manuals and parts fiche, if possible. Though you may not need much after you use these notes.
PARTS (all prices approximate):
- Release bearing+ #951.116.082.01 ESP
- "The Turbo Cup" clutch disc is the strongest and is highly recommended for the street, and is a must have for track use. It does not use the small springs that prematurely fail! It is available as a Porsche Motorsport part# 951.116.011.15.(07) Turbo S clutch disc: #951.116.011.15
- Pressure plate+ #951.116.023.01 ESP
- pilot bearing+ #931.102.111.00
- guide sleeve+ #016.141.181
- needle bearings+ (2 ea.) #999.201.213.00
- Cheesehead Bolts** (12 ea.) #999.510.012.02
- All new exhaust sealing rings & hardware= (bolts, nuts, washers)
- Intake manifold gaskets=(4ea.) # 944.110.163.05 (If manifold is removed)
- Fuel Injector Seals (4 kits) #944.110.901.00 (If manifold is removed)
- Sealing Ring #944.111.205.03 *** (Large)
- Sealing Ring #944.111.205.04 *** (medium) (4ea.)
- Sealing Ring #993.111.195.00 *** (Small) (1ea.)
- Sealing Band #951.123.134.02 *** @ $24.40 (1ea.)
**ESP = Denotes EuroSelect part**
- ** Replace any hardware that becomes damaged upon removal**
- I replaced all of these parts because of the labor involved to access them.
- *** Must replace exhaust sealing rings & gaskets if disassembled
FIRST, YOU NEED TO CHECK TO SEE IF YOU WILL BE ABLE TO MOVE THE DRIVE SHAFT One of the main reasons that the turbo clutch fails is that their are (6) small springs on the clutch disc. These springs prematurely break under wear and stress, and wedge themselves between the disc and other clutch parts. This is a really poor design on Porsche's part, and can be eliminated by purchasing the "Turbo Cup" clutch disc with the (07) suffix. This clutch disc is more robust and engages a bit quicker, but I feel the trade off is well worth premature clutch failure! The Turbo Cup disc eliminates those nasty small springs.
** With the rear wheels off the ground, the clutch pedal engaged, and the emergency brake released, check to see if you can turn the rear wheels. IF YOU CANNOT, JUMP AHEAD TO THE TRANSMISSION SECTION and follow the "added note" to align the drive shaft clamping sleeve Allen hex bolts.
SECOND, IT NEEDS TO BE DETERMINED IF YOU HAVE A SINGLE OR 2 PART CROSSOVER PIPE (the diagram is in the Turbo supplement (p. 30-3) All 86' 951's originally had the single part cross-pipe. Under warranty PCNA replaced the non-bellowed type headers when they cracked, with the improved accordion style. This was done for the first 5 years or 50K. The one part cross pipe was updated to the current two part type under "hidden" warranty with the headers.
The old style did not have a separate pipe going up to the waste gate. The clutch bell housing cannot be removed without this piece removed! Believe me I tried. So if you have the single cross pipe, it must be completely removed all the way up to the turbocharger. This involves removing the intake manifold, and lots more stuff in the engine compartment, in order to access the turbo exhaust bolts.
The cross pipe is only on the 951 models (turbo only) so if you have a 944 normal or plain "S", consider yourself lucky in this case. THIS CREATES A LOT MORE WORK!!! Lets hope you have the new 2 section cross-pipe!
- Jack up car & support with 2 jack stands
- Remove aluminum engine protection shield
- Determine which crosspipe you have (explanation above)
- If you do have the two part jump up and down and proceed to here
- This may be a good time to determine if you would like to replace the headers and crosspipe with the new updated parts. It's not cheap! I elected not to do it at this time. I hope the headers don't crack! If you have the single part pipe, lower the car and proceed as follows:
- This part of the job is much easier while on the ground
- NOTE: As parts are removed, label and store them in plastic parts bags. BE ORGANIZED!! BE ORGANIZED!!
- HINT! Be careful when removing and installing hardware in and around engine compartment. There are many "black holes" where nuts and misc. items just disappear. I used a shop rag just under the working area to catch falling objects. A telescoping magnetic pick-up tool works great for hardware retrieval!
- Place covers over fenders
- Remove battery ground (shield terminal from possible ground contact)
CRUISE CONTROL CABLE:
- Disconnect cable on cruise control motor (If applicable)
- remove retaining clip on cable
- loosen and slide cable housing locking nut toward motor
- pull end of cable housing through hole, slide cable through split in cable housing mount.
- remove cruise control cable clamp ( on manifold )
VACUUM, SPARK, FUEL:
- Pull off vacuum hoses on pressure regulator and pressure damper. ( inspect at same time) Replace if damaged. * Remove fuel Rail (be careful of plastic cap @ end)
- Remove distributor cap with spark plug wires (I left the cap on and just removed the spark plug ends wires only)
- Disconnect fuel connections to fuel rail: (2) (one is a clamp the other is a nut.) try to catch fuel that leaks out of the system. I covered exposed ends with plastic bags and wrapped with electrical tape. DANGER! Be careful with fumes from fuel. Work in a well ventilated area, and not around gas pilot lights!
- Fuel Injectors ( Carefully remove fuel rail from injectors starting at one end. More fuel will spill out of rail. Next remove injectors one at a time from the intake manifold Set aside.
- Hose clamps on many intercooler connections
- Remove black aluminum intercooler tubes
- Electrical connection to throttle body
- Throttle and cruise control cables w/ clamp on intake manifold.
- Vacuum tube at throttle body (underneath) 13mm bolt @ front 10mm bolt @ dipstick
- Remove dipstick shaft
- 2-5mm Allen bolts @ oil filter
- 10mm bolt @ electrical harness in back
** If intake manifold will not come loose, tap with rubber mallet to free manifold from the gaskets. Cover intake ports. Turn manifold over so turbo-charger is visible.
* Guard for master cylinder (2-10 mm bolts/3 nuts) difficult to remove/sharp edges/will bend to facilitate removal. Good luck! It is easier to access bottom two nuts when car is lifted.
Dual crossover 951 and 944na start HERE:
- Remove ground strap bolt @ top of Clutch bell housing (if removal of this ground bolt poses a problem I would remove the heater valve that is in the way) Removal will require bleeding & topping off coolant system . A 1/4" 10mm universal with a long 1/4" extension worked for me . NOTE: This bolt has been replaced with a 8 * 25 mm stud w/ copper nut. I really don't know if this will make things easier or not?
- Remove speed & reference transmitters (2) 10mm flex socket
- DG-D w/special spacer
- (replace bolts if damaged; turn side to side while pulling straight out.)
- A Note From Barry Lenoble about Sensor block removal:"I have an 89 turbo. On my car there were sleeves on the sensor mounting block that went into the bell housing. Unless you removed the sensor block, the bell housing would not come off. The sensor mounting block is held onto the rear of the motor with 2 Allen head bolts. I believe they are 6 mm, but I'm not sure. The problem is (of course) there is very little room to insert a tool into the head of the bolt and remove the bolt. I had to remove the heater hose (which I had to remove anyway to extract the sensors), and then I was able to insert and Allen socket into the bolt and turn it with a flex head ratchet. A stubby ratchet would have been better, but I didn't have one. After the bolts have been removed, the mounting block has to move towards the rear of the car, and then you can lift it out. Note that all three sensors must be removed before you can remove the mounting block."
- Remove cable clamp holding starter cable @ upper attachment point (on bell housing) 10mm bolt w/washer
- NOTE: This attachment point may be more accessible once central tube is disconnected from clutch housing.
- Raise car & support with jack stands
- ** A NOTE ON JACK STANDS** SAFETY IS VERY IMPORTANT!!!! Use the heavy-duty 3 ton stands with the lever (Imparts carries these @ $27.00 per pair.). Try to avoid the spot welded sheer pin type. The 6 ton jacks minimum height requires the use of smaller secondary stands, because it is very difficult to raise the car the 16" on the first lift. I would recommend the smaller 3 ton units with the lower minimum clearance( 12"). In order to raise it up with enough working clearance, it is safer to do this process in two stages, lifting one side at a time. An assistant spotting the opposite side is a great help. A working height of 18" worked well for me, this gave me enough clearance to remove the transmission. The 6 ton units would be required to get the full 24" clearance, but not necessary. Secure the stands at front and rear. I positioned the rear jacks under the rear axle cross member mount, and the front jacks at the front most jack points. Other positions may be used , depending on what jack stand pad configuration you have. For added stability , short 2*4's may be utilized between jack pad and lifting point . Find secure points!!
- Remove starter & slave cylinder exhaust shields
- Waste gate to exhaust clamp
- Disconnect Oxygen sensor
- Emission check tube (top bracket is attached with upper clutch bell housing bolt.
- Loosen (but cannot remove) waste gate bracket to torque tube (mark position)
- NOTE: Soak all bolts on exhaust system with Wurth Rost Off or equivalent prior to removal. A must for frozen hardware!
- Bolts at waste gate (4 nuts & washers @ studs, 4 bolts & washers @ threads)
- Bolts, washers, nuts at both exhaust manifolds (6)
- Bolts, nuts, washers at turbo(4) (top front is difficult to access; use 15mm crowfoot with short extension)
- Remove Cross-pipe
- NOTE: Always label wires & connections as to where they go
- Remove starter (2 electrical connections) replace black rubber protective boot if damaged
- Remove waste gate with holder (bypass valve) from central tube 2 bolts (disconnect hose clamp ; inspect vacuum hose for damage)
- Remove starter harness clamp at lower attachment point (replace if missing mine was.
- Remove clamp for hose to slave cylinder (be careful not to damage hydraulic clutch line)
- Remove exhaust clamp @ side of catalytic converter & remove short waste gate pipe ( probably not necessary, but I did this)
- Remove nuts, washers (4) at turbo exhaust pipe
- Remove bolts, nuts, washers (6) on the three exhaust hangers, hold level & lower down., (be careful not to damage threaded studs on turbo exhaust pipe.) Withdraw entire exhaust system to rear.
- Remove catalytic and rear muffler exhaust shields
- Leave exhaust hangers on rubber mounts.
Move on to Clutch Replacement - Part Two
> 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 Two
> 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
> Seat Back Brace Installation Instructions
> KLA Strut Brace Installation - 968/944 S2/944 S