![]() |
|
|
|
Registered
|
Do I have to replace my pressure plate during my clutch change?
Hi everyone,
I have an 84 3.2L Euro project coming to an end finally, I'm currently planning a transmission rebuild as well. I would like to know if I have to replace my Aluminum pressure plate as well or can I just do the clutch disc and release bearing? Thanks, Alex
__________________
Its easier asking dumb questions than fixing dumb mistakes 1974 Porsche 911 Coupe, RSR Project 1976 Porsche 911 Targa, Black 1986 Porsche 911 Carrera, Black 2006 Porsche Cayenne S, Black |
||
![]() |
|
Registered
Join Date: Oct 2003
Location: Michigan
Posts: 14,093
|
You could but why?
The money you save now will be spent later when you have to remove the engine to replace it. I thought about doing the same thing this year but my wife actually suggested getting the complete kit. I'm glad I did.
__________________
1981 911SC ROW SOLD - JULY 2015 Pacific Blue Wayne |
||
![]() |
|
I'm with Bill
Join Date: Jun 2005
Location: Scottsville Va
Posts: 24,186
|
JMO
When replacing any clutch pieces..............replace all of them, including all the bearings. You might consider having the plate re-built if it;s cheeper.
__________________
Electrical problems on a pick-up will do that to a guy- 1990C4S |
||
![]() |
|
Somatic Negative Optimist
|
If there aren't too many miles on the plate, I'd re-use.
Some people are easy on the clutch and it shows when you look at the components. Pilot bearing, release bearing and disc are relatively cheap. Where to stop? Have an experienced shop look at the plate and check the fork for cracks.
__________________
1980 Carrerarized SC with SS 3.2, LSD & Extras. SOLD! 1995 seafoam-green 993 C2, LSD, Sport seats. ![]() Abstract Darwin Ipso Facto: "Life is evolutionary random and has no meaning as evidenced by 7 Billion paranoid talking monkeys with super-inflated egos and matching vanity worshipping illusionary Gods and Saviors ". ![]() |
||
![]() |
|
Registered
|
Thanks everyone, I hope I didn't blow it. I bought an aluminum pressure plate in good used shape and was going to go knew with the rest of the hardware. Are there any dimensions I should measure to confirm it's still good, other than a visual inspection of the forks?
Regards, Alex
__________________
Its easier asking dumb questions than fixing dumb mistakes 1974 Porsche 911 Coupe, RSR Project 1976 Porsche 911 Targa, Black 1986 Porsche 911 Carrera, Black 2006 Porsche Cayenne S, Black |
||
![]() |
|
Registered
Join Date: Mar 2006
Location: Grand Rapids, MI
Posts: 245
|
What about resurfacing the flywheel? That is another step that's included in most descriptions of the job, but it adds a lot of work.
I resurfaced the (presumably original) flywheel 8 years (and probably 40,000 miles) ago when I rebuilt the engine. Is there an easy way to tell if it is OK without removing it? If I remove it I may well just replace it with a lightweight one while I am at it (this is a track car). Yet another slippery slope. Thanks Scott
__________________
1978 911SC RoW work in progress |
||
![]() |
|
![]() |
Bill is Dead.
Join Date: Jul 2005
Location: Alaska.
Posts: 9,633
|
My 2 cents worth:
All those neat little fingers on the pressure plate, collectively, are a giant spring. They are what create the clamping pressure to hold the clutch disc. Any spring, with age, will lose a portion of it's "springiness" and the result is loss of clamping force. If your pressure plate is old, I would change it. If your pressure plate shows signs of heat damage (from the clutch slipping) I would change it. If you have any reason to doubt anything about the pressure plate, replace it. That is, unless you really like removing the engine. But if your pressure plate is relatively new with low miles, then I would probably reuse it. I have my engine and trans out right now, and will be going with a new clutch disc during the reinstall. However the pressure plate is less than 2 years old and has very low miles - and will be reused.
__________________
-.-. .- ... .... ..-. .-.. -.-- . .-. The souls of the righteous are in the hand of God, and no torment will ever touch them. |
||
![]() |
|
Registered
|
In the midst of my complete engine and now transmission rebuild the part I kept was the pressure plate. Some yahoo had the clutch cable adjusted incorrectly when I purchased my SC and it was dragging. The disc was shallow, but the pressure plate was fine. My mechanic checked it out, and sent it out to be balanced with everything else on the motor.
__________________
2021 Model Y 2005 Cayenne Turbo 2012 Panamera 4S 1980 911 SC 1999 996 Cab |
||
![]() |
|
Grappler
|
The clutch disk and the pressure plate should always be replaced together, as well as resurfacing the flywheel. These parts need to wear uniformly. If you install a used pressure plate with a new clutch disk, their is a very good chance you will experience clutch jutter. Another item to change is the pilot bearing, and check the fork for excessive wear. Make sure you use new bolts when re-installing the flywheel as they can only be used once. It just doesn't make sense to go to the trouble of removing your engine/trans, than rebuild your trans, only to put in used parts. Just my .02
|
||
![]() |
|
Registered
Join Date: Dec 2001
Location: MA USA
Posts: 2,938
|
Quote:
__________________
Dean 911 SC turbo, 3.0L 930 motor, G50, 930 brakes, DTA EFI, 352 RWHP DynoDynamic dyno, |
||
![]() |
|
Grappler
|
Comparing a brake rotor to a clutch job may not be the best analogy, due to the level of difficulty in completing both jobs. I'm wondering if Dean is saying that using old parts CANNOT cause problems.HE may very well be able to identify acceptable wear on the pressure plate and flywheel. But based on determened"s initial question, I am assuming that he wants to do the job correctly the first time. It really comes down to cost vs benefit. The only benefit is that you will save a few bucks by using old parts. The flip side is; you will be using old parts, and you will probably be taking the motor out again soon to change the rear crank seal.
|
||
![]() |
|
19 years and 17k posts...
|
Buy the Sachs kit from our host and replace all of the components in the kit and you'll be glad you did...
__________________
Art Zasadny 1974 Porsche 911 Targa "Helga" (Sold, back home in Germany) Learning the bass guitar Driving Ford company cars now... www.ford.com |
||
![]() |
|
![]() |
Registered
Join Date: Dec 2003
Location: Arapahoe County, Colorado, USA
Posts: 9,032
|
I am a proponent of replacing even slightly suspicious parts. I’m
willing to spend a little more as opposed to risking an in-service failure. A clutch is on the low end of this spectrum because it is so easy to pull a 911 engine and replace a clutch. That said, there is a serious issue with Porsche clutches (’70 and later). The pressure plate is not designed to withstand use decelerating the 911 with engine inertia. The tension springs in the pressure plate are designed for only that use – tension. In the reverse direction (when the engine slows the car) the tension springs will buckle and ruin the pressure plate. Here is an example: ![]() The tension spring should be straight. In this case it has buckled and the guide pin is bent. The pressure plate is no longer centered in the housing. The symptoms here are big vibration and poor functioning of the clutch. Even subtle buckling renders the pressure plate poor functioning. Best, Grady EDIT for spelling
__________________
ANSWER PRICE LIST (as seen in someone's shop) Answers - - - - - - - - - - - - - - - - $0.75 Answers (requiring thought) - - - - $1.25 Answers (correct) - - - - - - - - - - $12.50 |
||
![]() |
|