Newbie questions on Clutch and adjusment

Sonic dB · Sonic dB's Garage

Can

marcesq · marcesq's Garage

1) When you say "clutch engaging" this is when you push down the pedal and the clutch then "opens up" at the flywheel allowing you to shift gears to match the RPM... Correct or incorrect??

(or is this properly called "clutch disengaging")??

PUSHING IN DISENGAGES THE CLUTCH (AND NO I'M NOT YELLING) LETTING OUT ENGAGES CLUTCH

How far down should one have to push the clutch pedal on a 915 in order for clutch to "engage" (if this is what it is doing)?

PUSHING DOWN DISENGAGES, DISTANCE DEPENDS ON ADJUSTMENT AND TYPE OF CLUTCH/PRESSURE PLATE IN SOME INSTANCES.

2) Define "free play".

AMOUNT OF PEDAL TRAVEL FROM TOP TO POINT WHEN THROW OUT BEARING STARTS TO PRESS AGAINST PRESSURE PLATE

3) How do you adjust free play?

THE BOLT THAT IS MENTIONED IN #4

4) What are you adjusting specifically when you tighten the bolt at the specified 1mm. (the one with the lock bolt to hold it in place)?

FREE PLAY

5) What specifically, are you adjusting with the 2 nuts which are located on the cable where it attaches to the tranny?

CABLE TRAVEL

6) What could one possibly do to mess this adjustment proceedure and damage the clutch??

* In other words....if it feels fine, shifts OK with no noticable shimmy or vibration....then is it ok?

IF FREE PLAY ADJUSTMENT IS EXCESSIVE CLUTCH CAN SLIP EVER SO SLIGHTLY CAUSING PREMATURE WEARING.

TOO LITTLE FREE PLAY AND YOU WILL HAVE A HARD TIME GETTING INTO GEAR.

7) BONUS QUESTION: Looking through the archives here at the forum, it has been recommended by some to "pry the clutch helper spring as far forward as possible before attaching the clutch cable and adjusting the clutch"

Is it proper proceedure to push clutch helper spring forward before attaching clutch cable....or not???

NEVER HAD TO DO THAT. I ATTACH THE CABLE TO THE CLUTCH ARM THEN PUT THE CABLE IN THE RETAINER BRACKET. MAKE SURE THE PEDAL IS UP ALL THE WAY AND THAT THE CABLE IS FIRMLY SEATED IN THE FIREWALL FITTING.

Sonic dB · Sonic dB's Garage

Marc....thank you for your answers. That certainly clears up a few things that I was wondering about, and now I see the light.

marcesq · marcesq's Garage

Glad I could help . . . usually I just muddle things up.

Gordo2 · Gordo2's Garage

I just adjusted my clutch for the first time today and had many of the same questions in addition to the following:

I noticed the lever arm that the adjustment bolt comes in contact with is worn with about a .5 mm divot from prior use (167,000 miles, not surprising).

How do you account for this when you are trying to adjust to spec? If I insert a 1.2 mm or 1 mm feeler, it blocks off the divot ultimately resulting an incorrect setting according to spec.

Should I work close to spec but close it down a little to account for the wear?

Gordo

911pcars · 07-31-2003, 09:03 PM

Marcesq responded with pretty accurate info. However, I'd like to butt in and clarify item no. 6.

If the free play is excessive (the distance the clutch pedal travels before the throwout bearing touches the pressure plate), this could reduce the travel needed to disengage the clutch; thus more difficult shifting.

If there is insufficient free play, the clutch could partially disengage and create slippage between the engine and transaxle, thus increasing clutch disc wear. No free play also causes the throw out bearing to constantly rub against the pressure plate; this increases wear in the TO bearing.

Just wanted to throw in another $0.02
Sherwood Lee
http://members.rennlist.org/911pcars

tsuter · 08-01-2003, 05:37 AM

Include the divot but ultimately the amount of gap is personal preference. How fast do you want the clutch to grab when releasing the clutch? Adjust accordingly. Small gap - grabs late - large gap - grabs fast. Just make sure there is some gap even if its just the divot gap. And not so large you can't shift as mentioned above.
I personnally like a small gap. Quick disengage with less pedal travel.

tsuter · 08-01-2003, 08:05 AM

Should have mentioned: if you just put in a new clutch then the gap should be left slightly larger for a little while until that clutch breaks in and seats. Then the gap should be readjusted. Or you WILL end up with a divot as that gap will close with a new clutch.