G50 tranny question...

[KFC911]

My car (58K miles) has developed a 'new issue' recently. My tranny has always been pretty smooth, but had the typical G50 symptoms of being a bit 'knotchy' going into 2nd (and sometimes 3rd) when cold. Just recently I've noticed that it's also starting to 'catch' just a bit when coming out of 3rd on a 3>2 downshift (more evident when she's cold). If I hesitate just a bit more (than I always have) before shifting out of 3rd, it's still nice and smooth. It's almost as if it isn't 'releasing' as quickly as it once did. I've tried different gear lubes (Mobil 1 then Redline) and now have Amsoil in her. It might be just a bit better with the Amsoil, but something is still amiss. I haven't bled the hydraulic clutch within the past year or so (if that matters), but intend to do so asap. Any similar experiences, ideas or suggestions? Thanks!

[Grady Clay]

Keith,

That seems like the clutch is not completely releasing quickly enough or completely. First try bleeding the clutch.

Could this be a symptom of a cracked clutch release shaft support in the transmission casting?

This also can be a symptom of oil on the clutch disc. Inspect for leaks. That probably won’t show any because even the tiniest bit of oil can cause this. Does the clutch tend to judder when slipping from a stop?

Another possibility is the clutch parts; disc-to-flywheel and disc-to-pressure plate surfaces have become shiny and tend to stick together.

Still another is the disc could be sticking on the splines of the transmission input shaft. This can be from lack of a little grease there or from noticeable rust.

If the clutch isn’t releasing properly, you can damage the syncro parts in the transmission (yes, even in a G50) and become a very expensive repair.

Best,
Grady

[KFC911]

Originally posted by Grady Clay
Keith,

That seems like the clutch is not completely releasing quickly enough or completely. First try bleeding the clutch.

Could this be a symptom of a cracked clutch release shaft support in the transmission casting?

This also can be a symptom of oil on the clutch disc. Inspect for leaks. That probably won’t show any because even the tiniest bit of oil can cause this. Does the clutch tend to judder when slipping from a stop?

Another possibility is the clutch parts; disc-to-flywheel and disc-to-pressure plate surfaces have become shiny and tend to stick together.

Still another is the disc could be sticking on the splines of the transmission input shaft. This can be from lack of a little grease there or from noticeable rust.

If the clutch isn’t releasing properly, you can damage the syncro parts in the transmission (yes, even in a G50) and become a very expensive repair.

Best,
Grady

Thanks Grady! I'm very much a novice, but I think you're correct in you assessment that the clutch isn't releasing 'quickly' (vs. not releasing 'completely') enough when cold, as I can simply wait a split second longer, and she'll come out of 3rd smoothly. I will definitely bleed the clutch, to see if that makes a difference. I'd read one of your other posts regarding oil on the clutch disc, but I don't have any of the 'juddering' you refer to. In you opinion, would any of the other possibilities you mentioned (cracked shaft, sticking clutch parts, sticking disc, etc.) virtually disappear after she's warmed up good? I'll bleed the clutch within the next few days, and report back on what I find. If the bleed doesn't help, I'm assuming that I'll need to drop the motor to investigate further. Since I've begun to 'baby her' on shifts (more than usual), she's very smooth, so I don't believe that I'm damaging anything else, but I sure don't want to have '$yncro repair$'. As usual, thanks for your input and advice!

[glennmathias]

Hello,
I have a 1988 911 3.2 with at G50. I love it, but the manual I have does not cover the transmission repair/service/specs. I would like to service the transmission (or repair some day, if nessary). Can anybody recomend a manual that has the G50 for the 911 1988 year?

Thank you,
Glenn