Transmission, Manual

Clutch Adjustment, Double Disc (early cars)

Clutch Adjustment, Double Disc (early cars)

Just wanted to share with everyone my success with adjusting my clutch on my 83S. Iíve heard many complaints about it being difficult to get into gear and that the syncroís are worn out. Iíve owned my car for about 10 years now, and from day one it needed new syncroís. I tried different gear oils and found the Redline 75w90ns gear oil to help the most. But it was a band-aid and not a cure. A few weeks ago I had to fix a leaking flywheel seal, and when I put the clutch back in it was harder to get into gear than before, took some pressure to get into 1st, 2nd and 3 rd gear, and even reverse. So I decided to adjust the pressure plate per what I call the ĎDevek Methodí. What a huge improvement, much, much smoother. The early clutches are sensitive to dragging, and if both discís donít release when you press-in the clutch pedal the transmission will be difficult to get in gear. The transmission is much easier to shift and it is even 50% better than I have lived with the past 10 years. Someday Iíll fix the worn syncroís (in another 10 years). If you do your own work on your car it is not a difficult job to perform. A copy of the Devek instructions is attached, below.

Randall Welch


Adjusting the 928 double disc clutch center ring.
The 928 double disc clutch is superior to any other production car clutch assembly. It is small in diameter, has a large surface area, low angular momentum and is easy to modulate. However, it does have one fault. Porsche discontinued the clutch at the end of 1986 because of continuing problems with having the clutch properly serviced in the field. If the center ring is out of position, the clutch, even in the fully disengaged position, will experience "drag". This drag will cause a creep when the car is standing still, in gear and idling. The clutch drag will also cause difficult shifting and grinding in reverse gear. The other aspect of the service problem is that improper lubrication of the clutch assembly and central shaft causes poor quality engagement and early failure of parts. The Fix: To properly adjust the center ring, remove the clutch cover and disengage the clutch by using a bar against the release bearing arm. In the disengaged position, the center ring should be equidistant from the flywheel and the pressure plate. If the center ring is out of position, reposition it by moving the adjusting forks of the center ring with a screwdriver. Rotate the engine by hand to gain access to each of the three adjusting forks. Disregard the dimensions given in the 928 factory repair manual! Lubricate all of the pivot points of the pressure plate diaphragm spring with dry molybdenum disulfide spray (such as Zep product #0073). Lubricate the central shaft and release bearing guide sleeve with moly paste. This procedure will assure easy modulation of, and long service life for, the double disc clutch assembly.

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