How My Porsche 944’s Clutch Gave Me a Heart Attack

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The drive home from work in the fall of 2018 was pleasant enough. Clear and sunny weather, traffic opening up for my Porsche 944. The car had been a solid commuter to this point. Reliable, respectable gas mileage, good visibility and quite fun to drive with its summer performance tires. The air conditioning kept the interior cabin pleasant and the stereo worked well enough for podcasts and audio books. The seats were comfortable for all 5’9″ of me. The brake and gas pedal were perfectly situated for heel-toe shifts.

Driving up the second-to-last hill of my commute, I let off the gas to stop at a light. Something felt off. All drivers know that sinking feeling when something expensive presents itself to the victim in the driver’s seat. Whereas once, the transition from on-throttle to off-throttle was as smooth as Downtown Freddie Brown’s jumper, it was now clanking like a Shaquille O’Neal free throw. There was a moment’s hesitation between lifting the gas pedal and the car slowing, as if the clutch were waiting a moment to catch.

I drove home and parked the car so I could perform further research. I found the two most common causes of my symptoms were a bad clutch and a worn transmission mount. If you read the headline, you know from which malady the car suffered. Sadly, I did not have the luxury of having read my headline. I decided “Well, it would be a lot easier to replace the transmission mount than the clutch. Let’s try that first”. Hey, it was worth a shot.

My research revealed a technique of “rebuilding” the transmission mount by wrapping it with masking tape and pouring urethane into the mount, thus encapsulating the metal part that attaches to the transmission in urethane. There were lots of write-ups about the technique and it seemed simple enough that even I couldn’t screw it up. Shocking, I know, but I actually did not screw it up. My daughter helped me swap out the old mount for the “new” used urethane-filled mount, and we went on our test drive.

Solid mount on the right, new factory mount on the left

Starting the car, I noticed it was harsher than ever. No doubt, because the urethane more solidly mounted the transmission to the car. More vibration was transferred through the chassis and into the seats. This would probably be a great solution for a track car, but my daily driver, which was already obnoxious with its aftermarket exhaust, was unsuited for this transmission mount. A quick tour of the neighborhood and I knew immediately the new mount did not solve my problem. With disappointment in my voice, I mentioned to my daughter that this could be it for the 944. Replacing the clutch involved either a great deal of time, or a great deal of money consdering the worth of the car. She didn’t approve of this approach, so I told her I would need to think about it.

I spent the next couple of weeks researching how much time it would take to put a new clutch in the 944, how the old clutch failed, which parts and tools I would need to accomplish this task and what the cost would be. It was a big endeavor, but I’ve taken big things on before and succeeded – building an engine for the Corvette, preparing the Celica for the 24 Hours of LeMons in far less time than one should take to prepare a Celica for the 24 Hours of Lemons. Having taken all of this information in, I still foolishly decided “Yeah, let’s do this.”

A Porsche 944 clutch does not fail like a traditional clutch. Porsche installed a clutch disc that utilized rubber instead of a traditional clutch that uses springs to absorb the shock of engaging and disengaging. The rubber version works well when new, but after thirty years, it dries up and cracks. Porsche’s mechanical “limp-home” mode when this happens is to rely on metal fingers to connect the clutch disc to the driveshaft. There was still plenty of friction material on the disc, the failure was in the rubber (that’s what she said). The new clutch disc, made by Sachs, is a traditional spring-type disc.

Worn rubber clutch
The backup tabs for when the rubber gives up

My clutch kit from Sachs arrived. I ordered a new clutch master cylinder, slave cylinder, pilot bearing, clutch bolts, flywheel bolts, fasteners for the exhaust, new exhaust hangers and went to work dismantling the car. The first step in changing a transaxle Porsche clutch is to remove everything from the car. Those things that one believes need to come out the least, need to come out the most. Off came the starter, clutch hydraulics, exhaust, driver’s seat, A BUNCH of wires and lines in inaccessible places under the hood have to be undone. Don’t even get me started on the speed sensors in the clutch bellhousing.

The new disc with springs instead of rubber

A quite difficult part of this whole process is removing the transmission, which is in the back of the car, connected to the engine via a torque tube. A crazy amount of time is spent finding the right angle, extension, u-joint and socket wrench to get to a bolt. It’s like some sort of sick puzzle thought up by a demented German person mad at the world because the breading on his schnitzel was soggy. The hex bolts holding the CV joints to the transaxle are prone to stripping and each one requires cleaning before attempting to insert a hex bit.

Resurfaced flywheel thanks to C&D Machine in Kirkland, WA.
Old throwout bearing vs. new

After days of struggling, I finally managed to take everything off of my 944. I sent the flywheel off to the machine shop for resurfacing. While the transmission was out of the car, I decided it would be a good time to purchase and install a short shift kit. only944.com makes a nice short shifter which I hoped would make things a bit more precise. The short shifter goes for $97. The short shifter was quite easy to install with the transmission out of the car. I installed a new factory transmission mount in the crossmember in place of the solid mount I had made. A few days later the flywheel was refreshed and I was ready to reassemble.

Short shifter installed

Not quite ready, I am afraid. I managed to get the new clutch on, the transaxle installed and then, in February 2020, I had a heart attack. As if that weren’t bad enough, they didn’t say “Go home, rest up and you’ll be fine.” They said “We’re going to cut your chest open and do a bypass. Triple bypass, actually.” That put a stop to any progress on the 944. I spent twelve days in the hospital and then when I got home, I couldn’t get out of bed without help. I had some healing to do before being able to drive, much less turn a wrench.

While in the hospital, COVID reared its ugly head and it grew into a world-changing event while I recovered. As weeks passed, I was able to do more and more, though the effort often left me so tired as to need a nap. Every once in a while I would steal a peek at the 944 on the lift and wonder if I should just have it towed to the Porsche specialist to finish the job. Or to a cliff to really finish the job. In the end, I decided I should suck it up and complete what I started, like I told my daughter I would.

In August 2020, I felt good enough to get back to work on the Porsche. Remaining tasks included installing the clutch master and slave cylinders, the exhaust, oxygen sensor, a cover under the dash and putting the seat back in. I purchased the car with an aftermarket exhaust that had no catalytic converter. The previous owner was nice enough to throw in the factory exhaust with the deal. It has always bugged me that the exhaust was so loud, particularly on startup. I decided to install the factory exhaust in an attempt to quiet things down a bit. These tasks were checked off with the help of my daughter, and it was time to bleed to the clutch.

We raised the back of the car, filled the Motive power bleeder with brake fluid and pressurized the hydraulic system. I opened the bleeder on the clutch slave cylinder and waited. And waited… and waited. Nothing happened. The fluid was not flowing through the hydraulic system. There was no resistance to the clutch pedal. We tried bleeding it by holding in the clutch and releasing the bleeder and by pumping fluid through the bleeder in the slave cylinder. We finally gave up and regrouped.

I speculated that perhaps the clutch master, though new, was bad. It’s not that unusual for a new hydraulic part to be bad from the factory. I ordered a new clutch master cylinder from FCP Euro and received it a few days later. I spent the better part of a Saturday installing the new part, attached the power bleeder to the reservoir and gave it 10 lbs of pressure. Releasing the bleeder caused fluid to flow almost immediately. I let it bleed for about ten minutes and closed the bleeder. I got in the car with some trepidation. Would the clutch work now? Would I have to convert the car to a mechanical clutch? Should I just get a Camry?

Pushing the pedal to the floor eliminated any fear of future Camry ownership. The pedal had pressure and popped back up from the floor. I installed the starter and went for a test drive. The clutch feels fine and normal and I was quite happy. There were a couple of things that weren’t quite right. The air conditioning had stopped functioning since I parked the car. This is not a major concern as we head into autumn in the Pacific Northwest, but I will need to address it. The turn signal failed to cancel on left turns, which is not a big deal because I don’t like to turn left any way. The steering wheel, removed for easier access to under the dash, was install one tooth off, an easy fix. The shifter required a bit more force to move, but the short shifts worked great and I knew exactly where each gear was.

If you, too, wish to embark on the adventure of replacing a 944 clutch, I urge you to do your homework. Clark’s Garage is an excellent resource, with step by step instructions on how to do each task. On YouTube, Van Svenson has an hour long video that nicely demonstrates the process. Take your time, be careful and if you aren’t sure of something, step back and do your research. Most of all, don’t have a heart attack. Happy motoring.

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