Can a clutch be pressed down for a few minutes without harm?

[GrindingGears]

So here's the deal. My SC is a little difficult when shifting into first gear from a stand still. Most of the time it shifts fine when I'm slowly rolling to a stop.

My tendancy is to down shift to first while still rolling and disengage the clutch (press is down) until the light turns green.

1) If I hold the clutch disengaged is this gonna burn it out, or hurt it over time?

2) I've heard that first gear is generally a pain in the ass with most SCs, fact?

[Drago]

Your probably not going to harm your clutch by holding the pedal down at stop lights....but you will harm your TO bearing, eventually.

[nostatic]

Following up on Brian's suggestion, I don't even put it all the way into second...just pull it back until there is some resistance, then slide it up.. That seems to "quiet" the tranny (the syncros maybe?), and it will usually slip right into 1st.

[fred cook]

You can not only shorten the life of the throwout bearing by holding the clutch pedal down, but could also shorten the life of the thrust bearing on the crankshaft. Remember that whenever there is pressure on the throwout bearing, the same amount of pressure is transferred from the pressure plate thru the flywheel and ultimately to the crankshaft thrust bearing. Basic laws of physics! I have a similar problem in that the PO somehow managed to completely wear out the synchonizer on 1st gear
in my Pcar tranny. I will get around to repairiing it someday, but for the time being, I use the method mentioned above of easing the shifter back into 2nd and the going for 1st.

Good Luck!

Fred Cook
'80 911SC

[GrindingGears]

i've tried shifting into second then to first....works sometimes...

this is what usually happens if first is giving me a hard time...

clutch, shift, doesnt go in.

sometimes if i'm in no nonsense mood i'll just force it in...it makes a terrible sound...no a grind, but a forced into the slot kind of sound (whatever that means)...

if i'm not willing to force it in then i'll try the shift into second then into first...

if that doesnt work i'll lift up the clutch and start over....

this can take some time...is a real pain in the ass on hills...and really pisses off the soccer moms who are three inches away from my bumper and ready to roll me over with their yellow H2....

i used to drive a 72T, we spent some money on the syncros and it shifted great...i would say shifting into first on my SC is worse than my old 72...

oh well, thanks for the repsonses.

[nostatic]

It sounds like your syncros might be tired, but try adjustements first. Also, the words "force" and "915 tranny" do NOT go together...well, unless you like cursing and rebuilding trannies.

[Shawzy]

A lot of us have this 'quirk' with the 915. I just rebuilt mine with fresh dog teeth and synchros on first, and I still have the problem you mention at times (about 1 in 10), although it was worse before rebuild. I.e. I would wait until your second gear dog teeth burn out before rebuilding unless it gets really bad.

Switching trans oil to Swepco 201 may help a pinch too.

When you have this problem, engaging second will help 'nudge' the dog teeth for first enough to line up with slider and is the best tip. Engaging first while still rolling helps a lot also, but I don't like to leave the car in gear with clutch down for the wear issues above and also for safety sake in case a soccer mom happens to rear-end me at a light.

Good luck and use this board - indespensible for all DIY P-owners!

[Sonic dB]

I have this same problem on my car sometimes... only 67,000 miles on it too.

Try blipping the throttle and then trying first. If the touching second gear thing doesnt do the trick for me, then I do the throttle blip.

The funny thing is that it works fine about 60% of the time with no need to do anything, just slips right into first.

* Also...do you have problems getting into second? I do and it sometimes feels like I am forcing it...so I try to ease it in there.

Ultimately a rebuild is in my future but I want to get it to 100K first.

[Early_S_Man]

grinding,

What is your clutch pedal free play adjusted to? Does your transaxle grind going into reverse?

My recommendation would be to do the following:

1. Rebuild your pedal box ... replace all bushings, and be sure to replace the eyelet where the clutch cable engages the clutch pedal lever.

2. Replace your clutch cable, and make sure it is well lubricated over the last three feet closest to the transaxle ... with Valvoline #985 or #986 SynPower Synthetic Grease with Moly. Adjust freeplay to 19 mm or 3/4" at the clutch pedal.

3. Replace ball-cup socket and shift-rod bushing, and shift coupler bushings if cracked or deteriorated ... 1-2 mm of longitudinal play is normal in the oval bushings' opening, from the factory, but ZERO axial play!

4. Replace your gear oil ... if dirty, flush first for 200 miles with Valvoline or Castrol, then Swepco! The Porsche-patent synchronizers in your 915 are extremely sensitive to gear oil contamination, hence the factory recommendation [per the 'spec book'] to change gear oil at the same interval as engine oil! With Swepco ... the gear oil should be changed annually, or every 20,000 miles.

[bigchillcar]

Warren makes an excellent comprehensive suggestion. I agree with the other gents on the selection of 2nd or 5th (works too) prior to shifting into 1st gear. Like nostatic, I just barely touch second gear and then up to 1st.

Definitely heed the advice of checking the clutch pedal freeplay. I find a need to adjust this maybe every six months, as my nuts drift (sounded odd). When I start having serious grinding issues I adjust the freeplay and it goes away. Do you know how to make the adjustment? It's an easy DIYer.
Ryan