987.2 Clutch/Transmission issue-

1964 Views 47 Replies 9 Participants Last post by RSchwerer, 3 mo ago

tjlacal

I'm a long time lurker, first time posting here and I could use some help with an intermittent 1st and 2nd trans grind when cold.

History:
I've got a 2010 Cayman 2.9l with the 6 speed with 37k miles, I bought it 8 years ago with 4k miles. 4 years ago the shift cables snapped and I brought it to my indy shop who replaced the cables and changed the trans fluid and the clutch fluid. The past 4 years I haven't driven it all that much, about 12k miles. Sometimes the car sits for a few weeks, but no longer than a month.

Issues:
In the past 2 years (about 5k miles ago) I started noticing a squeaking sound when the clutch petal was slowly depressed, no other symptoms.

3 months ago I started her up and it would not go into 1st or 2nd gear, but it went into all other gears fine. After 5 mins of running in the garage, i tried holding the shifter towards 2nd and it finally started to slide into 2nd gear and then I was able to get it in 1st. It seemed ok after that so I drove it around the block and got it up to operating temp. The next day when I went out for a drive it did the same thing.

Diagnosis:

I called my local indy shop and they suggested i tow it in. They had the car for about a week and they said they found no issues with it other than a slight grind in 2nd which happened a few times over test driving it and spending a few hours looking it over. They couldn't replicate the issue since it only happens when it's cold, they said that i just have to push harder into gear and it sometimes happens when these cars age. They changed the trans fluid and said the clutch fluid was fine. I went to pick it up and the engine was cold so it was doing the same thing. This time i pushed hard and it went into 1st and 2nd. The squeaking noise disappeared but the clutch has a weird springy binding sensation when you push it in slowly.

Yesterday I went to start it and it seemed worse. The car was on level ground in my garage, when started in neutral and cold, depressed the clutch and moved the shifter towards 1st, I had a sensation the car moved forward before i even put it in gear (as if someone was rocking the car from behind). For the first 3 miles it was very inconsistent, there was a slight grind when forcing it in 1st and 2nd but not all the time. As the car warmed up it drove completely fine.

This morning it did the same thing, but this time I noticed that sensation of the car moving forward was so bad that the car started to roll down out of the garage, over a rubber door seal I have on the garage floor and down the driveway without me even releasing the clutch or putting it in 1st.

Since the car drives fine when warm, I feel like I'll get the same response from the Indy shop. Does anyone have any suggestions on how to handle this or have had issues like this?

Thank you

See less See more

Save

41 - 48 of 48 Posts

deilenberger

· #41 · 3 mo ago

RSchwerer said:
I had an incident this morning that made me think of this thread. I am in the process of doing a brake job (pads & rotors followed by flush) on my 2010 Cayman 2.9L MT. The car is up on Quick Jack with wheels off. I just finished the last (left rear) wheel and wanted to test that the new wear sensors were all working, so I started the car and stepped out. It was in neutral. I noticed the left rear rear hub/rotor as slowly spinning. That's what reminded me of this thread. The right rear was stationary. After double checking it was in neutral, I put a gloved hand on the rotor and easily stopped it. When I let go, it remain stationary, but with a slight nudge, it started again. Is this normal?

Oh, one other odd thing associated with the above. I was able to start the engine without getting in and pressing the clutch or brake. I assumed my clutch switch is faulty and don't think it is related to the rotation.

If I was asked to guess - my WAG is a pilot bearing going bad. That's the bearing in the center of the flywheel that the nose of the transmission input shaft goes into. Usually it just spins. If it starts to drag probably the only symptom would be what you've experienced. And perhaps some noise under the conditions you're seeing the tire slowly spinning.

Manual Transmission Pilot Bearing Diagnosis

Pilot bearings make their most noise when the pedal is completely depressed. The pilot bearing makes noise when the input and crankshaft are rotating at different speeds. This works the bearing. Diagnose the pilot bearing in comparison to the release bearing.

www.freeasestudyguides.com

In any case - R&R of the transmission and clutch assembly is required to replace it, so if the car has some miles on it you might consider installing a complete clutch assembly (minus the flywheel unless it's visibly burned or warped.)

5 Bad Pilot Bearing Symptoms (and How to Fix It) - My Car Makes Noise

The clutch and transmission have two crucial bearing types; the clutch release bearing and the pilot bearings.

mycarmakesnoise.com

Save

Reactions: 1

RSchwerer

· #42 · 3 mo ago

deilenberger said:
If I was asked to guess - my WAG is a pilot bearing going bad.

Thanks. The car has 95000 miles and has never had any transmission work except a fluid change at about 62,000 miles. I used Redline (non-limited slip).
Since I'm not getting any noise or other side-effects, I'll just keep an eye (or ear) on it. There is no noticeable issue with clutch wear since I always try to rev-match and don't drop the clutch or do burn-out launches. But I know there'll be some work in the future and all the components in the drive train will be evaluated at that time.

Save

Reactions: 1

gubi

· #43 · 3 mo ago

So, it's not clear to me that you have a problem, and it definitely ain't a clutch problem. With the car in neutral and the clutch not pressed down, the clutch is fully engaged and the engine is transmitting power into the transmission. So in the situation you described the input shaft, the layshaft, and all of the gears in the transmission are spinning.

The output shaft should not be spinning because the car is not in gear (shifting into gear connects the output shaft to one of the gears spinning on it, but you haven't done that). What I suspect is happening is that with cold, thick gear oil, there's enough friction that the spinning gears are applying a little rotational force to the output shaft, and that's giving you the lazy wheel spin.

So I haven't tried this on the 987, but from the description and the way things in the transmission work I don't think you have a problem.

See less See more

Save

Reactions: 2

RSchwerer

· #44 · 3 mo ago (Edited)

gubi said:
don't think you have a problem.

Yeah, that's what I was thinking. The car was stone cold after it had been up on Quick Jacks for a couple days. Additionally, since I had just changed the rotor & pads, the pistons were still fully compressed into the caliper. So there was next-to-no resistance. I might try it again now that the brake job is done and I can get it to normal operating temp.

Save

deilenberger

· #45 · 3 mo ago

RSchwerer said:
Yeah, that's what I was thinking. The car was stone cold after it had been up on Quick Jacks for a couple days. Additionally, since I had just changer the rotor & pads, the pistons were still fully compressed into the caliper. So there was next-to-no resistance. I might try it again now that the brake job is done and I can get it to normal operating temp.

With those additional facts - I have to agree with @gubi - there is no problem. I often see exactly the same thing if my motorcycle is on the center stand with the engine running and the rear wheel off the ground. The only difference is - the motorcycle makes some clacking gear noises since it's a twin-boxer engine (widely separated power pulse) the engine actually accelerates and deaccelerates a bit when at idle (not noticeable on the tach, but noticeable from the gear rattle noises.. they go away if I gently apply the rear brake..)

Save

Reactions: 1

tjlacal

Discussion Starter · #46 · 3 mo ago

Problem solved: the trans was dropped and the clutch assembly was inspected. The pressure plate had very little wear on it and the flywheel was in excellent condition as well. The clutch disc had a slight warp to it when it was laid flat on the bench, warped enough to cause the disengagement issue. The shop owner commented that everything appeared to be taken care of and that it wasn't abused based on his inspection.

A new OEM Porsche Clutch disc, Pressure plate, bearing and clutch fork was replaced. The original flywheel was reused as he said it was in excellent condition. At some point he felt their was air in the clutch fluid line and he bled it once more and he noticed the pedal was firmer. all in all the issue has been completely resolved and so far I spend the weekend driving it around on the highway and in stop and go traffic so there's been over 100 miles added to it.

I also went with the OE GT3 shifter assembly. I can't say for certain that I noticed very much difference from the factory Cayman shifter assembly but the action is so smooth and it goes into gears alot easier then I can remember, especially 1st, 2nd and Reverse gears.

I asked for the original parts back as I'm planning to make a garage clock out of the old pressure plate and clutch disc. I may try to reuse the fork and bearing as a pendulum, but we will see what I can come up with. Here's a photo of those old parts, considering that there was a disengagement issue I'm surprised they look as good as they did.

Thanks for everyone's guidance, special shout out to Don

For those of you who are in Ventura county California and wanted to know more about the shops I've had encounters with feel free to PM me.

Cheers

See less See more

Save

Reactions: 5

deilenberger

· #47 · 3 mo ago

YEA!

Save

RSchwerer

· #48 · 3 mo ago

Great news. BTW, the GT3 shifter is just a beefed-up version of the original stock one. Some metal vs plastic parts. Same throw. Yes, it will have a slightly nicer feel - but probably so would any new shifter. I'm sure the installer also checked the alignment (tool included with the new shifter) so you're probably noticing that change as well.

Save

41 - 48 of 48 Posts

Top Contributors this Month