915 Transmission Quirk

car911 · 04-03-2002, 11:24 PM

My 84 915 transmission shifts fine but I am wondering about one quirk.

On the odd occasion when I come to a full stop from 4th or sometimes 3rd gear (eg. running at speed in 4th gear and for some reason come to a full stop), I find that it takes considerable force on the shift stick to get it out of gear.

Normally, I can shift it in and out of any gear with almost no pressure.

Any idea why?

jluetjen · jluetjen's Garage

My >>> guess <<< is that your clutch is not fulling disengaging and thus keeping the gears partially loaded.

Do you coast to a stop with the clutch to the floor and the car in gear? Do you put the car into neutral when stopped at lights or stop signs or do you just keep your foot on the clutch? If you tend to keep you foot on the clutch, you might want try dropping the car into neutral and then releasing the clutch instead. It should lesson the future wear on the clutch.

DJB · 04-04-2002, 05:17 AM

Sorry I cannot help, but I am not convinced it is a clutch problem.

I have a similar problem and have read previous posts on this topic.

When undergoing a hard run, mine takes considerable force and a double de-clutch on ocassion to get from fifth to fourth, its pretty un-nerving at the time.

If you can throw some light on this quirk, I would love to hear.

jlex · jlex's Garage

My '85 Carrera would sometimes experience a sticky 3rd gear if I let it stop in 3rd. To avoid it, I simply make sure I always shift into neutral before rolling to a stop. Never experienced stickiness in getting out of 3rd when the car's rolling. The car ought to be in neutral when stopped for a light anyway (as opposed to holding in the clutch) so maybe its the car's way to telling you how to shift it correctly.
regards,
jlex.

Formerly Steve Wilkinson · 04-04-2002, 05:37 AM

It's not a clutch problem. It's a not-uncommon situation that is in part caused by the way the snchro mechanisms wear and in part by improper linkage adjustment. Readjust the shift linkage (at the back of the center tunnel), which is extremely easy to do. Lemme know if you need specifics, though there is, I believe, an article on the prodecure in the Pelican tech articles collection. There are a variety of 915 "problems" that are all cured by proper adjustment of this crucial linkage. (Assuming, of course, that the linkage itself and its bushings are in good condition.)

Stephan

john walker's workshop · 04-04-2002, 08:05 AM

often the hubs that the operating sleeves slide on have fairly deep notches worn into them by the op sleeves being thrusted against them for many years. 5th seems to show the worst wear. the notches can hang up the op sleeve as it tries to move back into neutral or the opposing gear. dry splines where the clutch disc sits on the mainshaft can also keep the disc from finding a center position when released where it won't drag on the flywheel or p plate, causing difficult shifting.

avendlerdp · avendlerdp's Garage

I'm telling you it's the clutch! I know it seems wacky. Try giving it a twist less freeplay and see what it does. Otherwise Mr. Walker may be correct. Good luck. I cured mine in 15 minutes though!!

tbitz · 04-04-2002, 09:08 AM

There is an easy way to test if the clutch is dragging. Come to a complete stop in neutral. Press the clutch and hold it pressed for 10 seconds. Then try and put it in reverse. Reverse has no synchro, so if you hear gears grinding then you know your clutch is dragging. If it goes in reverse without any gear noise then your clutch is not dragging.

car911 · 04-04-2002, 12:14 PM

In my case, I don't think it is a dragging clutch. (And I never leave my foot on the clutch unless I am actively shifting).

The point is that the car shifts very smoothly in every other situation. The only time it sticks is, for example, an emergency stop while running in fourth gear and I don't have time to shift to neutral before coming to a full stop. Then, it takes quite a bit of effort to pull it into neutral. However, if I ease the clutch just to load the the gears slightly, then attempt to shift, it usually works OK.

I tend to favour the idea that it is a combintation of synchro or sleeve wear plus linkage adjustment. I wonder, for example, if the sudden deceleration from speed is jamming the linkage by a tiny amount, enough to cause sticking.

911boost · 911boost's Garage

Just to pitch in here, I had the same problem with 5th gear. I thought it might be the synchro's getting stuck, but after reading info on this board I (with help..) adjusted the linkage and it works fine now. It would do the same yours is, if I had to stop quick it would get stuck and I felt I had to really "pull" to get it out of gear.

Hope that helps some.

Bill

86Carrera · 04-07-2002, 01:16 PM

I had mine rebuilt and new clutch and it does the same thing. I have the feeling it's the way these things are made and have learned to shift to neutral before coming to a stop. It feels like it is much easier on the car, like mentioned in an earlier post maybe it's the car's way of telling you how to drive it.

Not saying it can't be the clutch but I don't think it is.

Would be interested ito know if anyone else got improvement from adjusting the linkage.