Transmission / clutch failure - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Roosell · 03-09-2010, 11:32 AM

Has anyone experienced something similar to this? Any mechanics who will offer their opinion?

I have a 2003 986 with 60,000 miles. I’ve had no problems with the clutch or shifting the 5 speed manual since buying the car 6,000 miles ago. Recently I was cruising in traffic at about 35 MPH. When I lifted off the throttle, I heard and felt a clunk that was not present before. For the next two miles of city driving I listened to something clunk each time I opened or closed the throttle. I stopped and completed an errand, and when I returned I noticed the shifter didn’t want to go into first gear. Second and third felt the same, but first took significantly more effort than usual. I knew I had a problem so I tried to tip-toe home. I noticed that even as I slowed for stop signs with the clutch in, the shifter resisted first. Usually I would expect the speed of the car to ‘sync’ with the engine, which should let first gear ‘fall in’. The two times I tried that it didn’t work. The transmission didn’t want first at all. I started leaving the transmission in second, and rolling through stop signs.

On the final 2 miles home, I was on a highway. As I reached 55, I shifted into fifth gear. As soon as I let the clutch out it made a horrible medium-pitch grinding noise, and at that point I lost all forward locomotion. I coasted to a stop and found that no gear (including reverse) would move the car. I could put the transmission into a gear, but upon releasing the clutch there would be a significant grinding / whining sound. The entire event- from everything is wonderful, to first clunk and finally stranded on the shoulder- took about 6 miles.

I am a little concerned with the diagnosis from the local shop. They ‘think’ it is a clutch / throwout bearing / pressure plate issue. Could this be the clutch assembly?

Thanks in advance!

yimmy149 · 03-09-2010, 11:42 AM

Other things to consider:

At 60k your front engine mount is shot unless it's already been replaced. The clunking you hear could be your engine moving.

It's worth checking that your transmission linkage is still connected. Does the car feel like it's going into gear as you move the shifter?

gschotland · 03-09-2010, 12:34 PM

I was thinking bad clutch and/or clutch hydraulics (master cylinder). 60k is a long time for a clutch to last, although mine went to 70k and had 5-10k left in it. It's not uncommon for them to last only 30k. It all depends on what kind of driving was done and how hard drivers were on the clutch.

As long as the gearbox is being pulled you really should do the rear main seal; it's inexpensive (~$120 for parts). There's a fairly good likelihood you'll need a new flywheel as well, and you might also want to consider replacing the IMS bearing. If you're in for the long haul in terms of ownership, these things are all worthwhile IMO.

Let us know how it turns out.

Roosell · 03-09-2010, 12:37 PM

The shifter did feel like it was still connected. I can't be sure it was TOTALLY connected, but I could feel the gates between the gears. Another question:

RMS = Rear Main Seal

IMS = ? Main Seal?

BYprodriver · 03-09-2010, 12:44 PM

Quote:

Originally Posted by Roosell

The shifter did feel like it was still connected. I can't be sure it was TOTALLY connected, but I could feel the gates between the gears. Another question:

RMS = Rear Main Seal

IMS = ? Main Seal?

Intermediate Main Shaft

are you in AL ?

Roosell · 03-09-2010, 12:48 PM

Si. Trussville.

texomawaves · 03-09-2010, 12:50 PM

I'm gonna guess the tranny is toast!!!!!!!

:ah:

BYprodriver · 03-09-2010, 01:50 PM

Quote:

Originally Posted by Roosell

Si. Trussville.

Sounds like the trans needs to come out. Grays Auto service on Hwy 11 is good & honest.

gschotland · 03-09-2010, 01:53 PM

It seems odd that you'd go so quickly from a perfectly working trans to not being able to shift at all. From what I've read about trans failures they don't typically happen like that; it's more of a slow deterioration starting with the 2nd gear synchro. That's why I was thinking a loss of hydraulic pressure due to a failed master cylinder and/or clutch failure.

If you rule out the gearbox linkage, you might want to consider getting the job done by Flat6 in N. Georgia if you're thinking of getting the IMS bearing retrofit. Jake did a great job on mine.

Jake Raby · 03-09-2010, 05:33 PM

Could be the clutch assembly, but could also be shifter related as the pieces under the shift console are weak plastic. I have broken one of these in my own car while purposely abusing it.

It doesn't sound like the gearbox internals to me at this point.

MN 986 · 03-09-2010, 06:11 PM

Quote:

Originally Posted by yimmy149

Other things to consider:

At 60k your front engine mount is shot unless it's already been replaced. The clunking you hear could be your engine moving.

It's worth checking that your transmission linkage is still connected. Does the car feel like it's going into gear as you move the shifter?

+1 on checking the front engine mount. I have a 2002 986 with similar miles, and I just started noticing a very slight noise under these conditions. I have read many posts on a few different forums, and I am convinced it is the front engine mount.
It is worth checking since it is a lot cheaper than pulling the transmission.
Good luck!

Roosell · 03-10-2010, 01:03 PM

Thank you to each of you for the responses.

R~

Lil bastard · 03-10-2010, 05:30 PM

Not tranny or engine mount, at least not initially. It may have taken the engine mount with it.

What I think you have is failed clutch mechanicals - TO, Pilot bearing and/or pressure plate.

Could be shifter mechanism too, but I'm betting clutch.

Cheers!

Roosell · 04-09-2010, 12:18 PM

The verdict: Clutch assembly. The repair shop insists that the clutch in the car was the wrong clutch (possibly a disk and pressure plate from an S model?). The center of the clutch disk was larger than the transmission input shaft, and they were surprised the car ever moved. Fortunately the input shaft wasn’t damaged when the clutch plate finally lost its grip and started freewheeling. The pressure plate fasteners weren’t completely tightened / flush, and had struck something while rotating. They were bent, and had to be cut out.

The pressure plate diaphragm fingers didn’t match up with the throw out bearing properly. The bearing barely touched the fingers. The rub marks are visible at the very tips of the fingers, and it looks like eventually the throw out bearing would have been pushed inside the ring of fingers. For sure, the clutch peddle action is much lighter now! The flywheel was damaged, so I got to buy another one ($900!). This has been quite expensive. Thanks for the input, guys!