Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

928 CLUTCHES

Thread Tools
 
Search this Thread
 
Old 06-19-2001 | 02:41 AM
  #1  
Lars's Avatar
Lars
Thread Starter
Instructor
 
Joined: Jun 2001
Posts: 115
Likes: 0
From: Near Edmonton, Alberta
Post 928 CLUTCHES

Do you guys burn out clutches with all the low end torque.
I have heard that that is part of the reason 70 percent of the 928s bought in a certain time period were autos (also the fact that its a lux car and a cruiser).

But seriously, do you burn out clutches easily. Or is it just a myth. I am afraid of this. I have a 931 and am done with it but looking for 928.
Old 06-19-2001 | 04:18 AM
  #2  
DoubleNutz's Avatar
DoubleNutz
USMarine
Rennlist Member
 
Joined: May 2001
Posts: 3,640
Likes: 68
From: Brush Prairie, Washington
Cool

Not a lot of experience burning out the dual disc pre-87 clutch. However, I have had one in the 85 and it took a extreme dump at about 6500 rpm.
Old 06-19-2001 | 09:36 AM
  #3  
Ed Ruiz's Avatar
Ed Ruiz
Burning Brakes
 
Joined: Jun 2001
Posts: 778
Likes: 1
From: Herndon, VA
Wink

A 928 clutch can last 150k miles or it can be used up in 50k miles, it mostly depends on the driver.

If you can be gentle on the clutch during up-shifts AND down-shifts, then it should last a very long time. YMMV.
Old 06-19-2001 | 03:28 PM
  #4  
Lars's Avatar
Lars
Thread Starter
Instructor
 
Joined: Jun 2001
Posts: 115
Likes: 0
From: Near Edmonton, Alberta
Post

That is not nearly as bad as I thought...I hate it when people spread rumors, I swear everyone with Porsches is out to "get" the other guy with another model number, 911s won't believe a 924 turbo "S" in 1980 had better G force in lateral acceleration than the 911 SC in mid 80s, and boxters and 911s don't know 928s can eat them alive. And then there are the 928 owners who say that the weight of the 928 doesn't affect its handling... kmmmph

[ 06-19-2001: Message edited by: Lars ]
Old 06-19-2001 | 03:42 PM
  #5  
John N's Avatar
John N
Cruisin'
 
Joined: Jun 2001
Posts: 9
Likes: 0
From: New Orleans
Thumbs up

Lars,
According to Devek, the dual disc clutch is one of the best production clutch set ups made. The real problem was in the adjustments, most repair shops did not know how to properly adjust the clutch. The result premature burn up. However, Devek provides a great tech tip for the adjustment. I can testify to it's accuracy. My '84 Euro S, 5spd leaves pretty hard, lots of surface area on the dual discs.
Good luck in your shark hunt!
Old 06-19-2001 | 07:12 PM
  #6  
Lars's Avatar
Lars
Thread Starter
Instructor
 
Joined: Jun 2001
Posts: 115
Likes: 0
From: Near Edmonton, Alberta
Post

ok so they didn't know how to adjust them...how? the clutch ride height, or something more complicated like angle ?
Like lets say i do a clutch on a 928 cuz it needs one...whatdoya gotta do to do it right, whats teh big mistake the guys made, one clutch wore out more than the other since its dual?
Old 06-19-2001 | 09:11 PM
  #7  
John N's Avatar
John N
Cruisin'
 
Joined: Jun 2001
Posts: 9
Likes: 0
From: New Orleans
Cool

Lars,
Here is what Devek says about the adjustment.
They were also very helpful over the phone when the job was being done.

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.

I hope this helps.


Old 06-20-2001 | 01:47 AM
  #8  
Lars's Avatar
Lars
Thread Starter
Instructor
 
Joined: Jun 2001
Posts: 115
Likes: 0
From: Near Edmonton, Alberta
Thumbs up

wow i have never had someone spend so much time on me, i really like these 928 guys (other than the drunk ones, but they also seem nice), its not just the cars, its the people

You know what...there was also something similar to this with other porsches, but not because it was out of adjustment, but rather because of the clutch disc design. The little slots in the clutch help dislodge it, if it is a smooth clutch like sachs makes its bad for a vacuum holding it
Old Yesterday | 12:04 PM
  #9  
dday830's Avatar
dday830
Rennlist Member
 
Joined: May 2023
Posts: 181
Likes: 28
From: Berlin
Default

Originally Posted by John N
Lars,
Here is what Devek says about the adjustment.
They were also very helpful over the phone when the job was being done.

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.

I hope this helps.


Gents,

This adjustment looks like a contentious point, and one with too much information....

Are there any pictures of what the section I highlighted looks like when properly centered?

Am getting set to pull the Transmission, TT & thereby clutch on my 928 (will photodocument on "west German Car in Trabi Garage").

never worked on a dual plate and need a few more visuals if posible other than what is in the WSM.

Many thanks as always,

DDay

Last edited by dday830; Yesterday at 03:42 PM.
Old Yesterday | 12:16 PM
  #10  
Darklands's Avatar
Darklands
Rennlist Member
 
Joined: Jul 2008
Posts: 2,781
Likes: 1,226
From: Near Hamburg-Germany
Default

I must do this this winter also!
Old Yesterday | 03:40 PM
  #11  
dday830's Avatar
dday830
Rennlist Member
 
Joined: May 2023
Posts: 181
Likes: 28
From: Berlin
Default

Originally Posted by Darklands
I must do this this winter also!
Ich vermute, dass es sich um eine norddeutsche Winteraktivität handeln muss, da wir keine Bowlingbahnen wie die Amis haben ...?




All times are GMT -3. The time now is 05:18 PM.