'83 up, a worn out clutch is determined when the front edge of the release arm reaches the end of the inspection hole?

If I read the WSM correctly, then about how much life is left in my clutch? Any pics of a new clutch?

I think the splined shaft has a lip, because it catches just a little, and/or the ball cup bushing is bad.

You can also see the sides of the clutch discs if you look carefully along the edges if you can see the wear grooves it should give a reasonable idea of how much disc you have left.
Also correcting (replacing ) the worn release arm bush will change your measurements.
If you opt for a new stub shaft it would also be a good idea to replace the pilot bearing and check the TOB, remember the TOB is spinning all the time the engine is running.
Make sure to get the Hi temp Porsche grease for the stub shaft, this should help it last longer without corroding, dont wash the engine as water will run down the top of the bell housing ( where the hole for the release arm is) and then damage the TOB and pilot bearing

+1


Also, Ken, if *I* read the WSM correctly, it looks like you've got about 2/3's of the discs left. But, we need to get a twin-disc clutch guy in here, 'cause I never answer twin-disc questions right...

Ken,

I won't call myself an expert but I have had EVERY single part of mine out and replaced at least once in the past 2 years. I think Dave is right, on the '85 you get until the front edge of the release arm is all the way at the front of the hole. I have my car up on jackstands for the weekend so I can get a pic of where mine is (only 1 year/ 6k miles old) later today.

I would go for ALL of the bushings before you do the clutch, just because they're all wear items and they're all relatively cheap and easy to replace (although the clutch in the '85 is very easy even though the pins challenged me a bit).

Forward shift ball cup
Release arm ball cup (top of bell housing)
Rear shift coupler
Shifter bushings (I haven't done these yet, but I hear they only take 30 minutes as well).
Your shifting will be transormed when all of these are new if they're anywhere near as bad as mine were.

FYI- for the centering spring in the trans (not the reverse lockout spring, but the one that you flex when you go into the 1/R plane) is flexed the ENTIRE TIME you are in 1 and R, not just on that end of neutral so you might want to get out of the habit of keeping it in first at lights. Eventually this spring will fail and you don't want to speed it along. Also, several people recommend adjusting it relatively loose for the same reason (with the nut on the side of the trans).

Just my .928


Edit: Here's where mine is:

Ken-

I have an almost new dual disc setup that I'm going to be putting in soon, I took some measurements today. One disc is almost new ,still has the Sachs printing on the friction surface, the other is a little more worn.

Discs:



Newer disc: 7.98 mm


More worn disc: 7.84 mm

Good info, everyone!

Thanks for the perfect pic, Mike. It looks like I'm good for a while.

Here's the relevant WSM page. I also adjusted the pedal rod and spring, according to the second page, and it improved the shifting quite a bit. (The spring was adjusted to <21mm, as if someone used the later measurement in error.) I removed the rubber...pedal cover too...for better feel.

Pull the discs and check the material above the rivits. I found the inspection hole estimation to be WAY off. When I first checked mine, th inspection hole method was worse than yours yet the discs were near new by the disc measurement. The problem was both the ball cup and the throw out bearing.

Why bother with that basic stuff?

I was busy this morning putting on things I don't really need, like the ol' eBay mini starter I had on my '81. It makes that racy starter sound. (woo ooo)

I checked the transaxle oil level, and it was ~3/4" low (leaky front seal). I topped it off with some dyno gear oil I had laying around. (I will change to syn, soon.)

After a few days, the shifting improved markedly, as if the syncros came unstuck or something. I have gotten used to the shifting, and have even speed shifted a few times, successfully trouncing lesser cars.

Today, a SL500 (2002-2006, 302hp/339tq) was roundly defeated from a dead stop. First to the rev limiter, second, third, easy-peasy. All the while the lil' 225s were scratching and clawing for grip. (Caveat: the SL weighs at least 1000lbs more @ 4200lbs! I'm easily <3200, and falling.)

Of course, once the '85 is sorted, I'll be hunting for 550s...and someday, 55s...