dying flywheel - what are the signs
Discussion
Before you ask - search function doesn't work! Even tried a google but all I found was people moaning about the 964 DMS.
I think my 997 C4S is suffering from a dying flywheel. Typically what are the signs? My 911 makes an interesting whirring noise at 4k rpm if I shift gear and my first gear currently has the fluidity of a Victorian signal box.
Suggestions?
I think my 997 C4S is suffering from a dying flywheel. Typically what are the signs? My 911 makes an interesting whirring noise at 4k rpm if I shift gear and my first gear currently has the fluidity of a Victorian signal box.
Suggestions?
If I read the symptoms right they do not point to a flywheel but more likely a release bearing. That is generally any time when you depress the clutch if you hear a noise the release bearing has to be suspect.
If gears are hard to engage the clutch can be dragging which can be a release bearing or simply a fluid problem. Which brings me to: Has the clutch hydraulic fluid been flushed/bled? This is supposed to be done every 2 years at the same time the brake fluid is flushed/bled.
Sincerely,
Rockster.
If gears are hard to engage the clutch can be dragging which can be a release bearing or simply a fluid problem. Which brings me to: Has the clutch hydraulic fluid been flushed/bled? This is supposed to be done every 2 years at the same time the brake fluid is flushed/bled.
Sincerely,
Rockster.
A clatter on switch off shows a weak flywheel. This noise can have other causes and some cars will do it as standard so don't everyone start to panic ! You have to know what you're listening for.
Your problem sounds clutch rather than flywheel related. Struggling to engage 1st geat means the clutch is dragging and turning the gearbox input shaft. Get is looked at sooner rather than later so as not to put undue strain on your gearbox. A clutch is not the end of the world, a gearbox would ruin your day
Henry
Your problem sounds clutch rather than flywheel related. Struggling to engage 1st geat means the clutch is dragging and turning the gearbox input shaft. Get is looked at sooner rather than later so as not to put undue strain on your gearbox. A clutch is not the end of the world, a gearbox would ruin your day
Henry
An audible thump from the back of the car as you pull away plus considerable backlash in any driven wheel if you jack a corner. My DMF was toast several years ago - about 25mm radial play on the outer circumference.
And it was not covered by the Porsche warranty even though I complained within days of taking delivery of the car that there was a problem. Yes, another vote of confidence in the OPC warranty!
And it was not covered by the Porsche warranty even though I complained within days of taking delivery of the car that there was a problem. Yes, another vote of confidence in the OPC warranty!
Unfortunately, I've been on the receiving end of this problem - the DMF in my last car (997S.1) completely failed. I'd driven to a client's office and reversed into a parking spot with no sign of anything being wrong with the car at all. When I came to leave, I started the engine, put the car in 1st and..... there was literally no drive whatsoever as I let out the clutch - nothing, nada, the car wouldn't move.
A phone call to my local indie and a (very embarrassing) extraction of my car by trailer from my client's car park later, the car was on the ramp and the gearbox in the process of being removed. Later that day, the indie rang me to tell me he'd narrowly escaped serious injury as he removed the gearbox from the car. Apparently, the complete outer section of the flywheel - complete with clutch - literally fell off the back of the engine and barely missed hitting him as it crashed to the floor!
Looking at the remains of the flywheel the following day, it was very apparent what had happened. (The next bit's from memory, so forgive me if I have some of the minor details wrong). The flywheel is composed of 2 parts (hence dual-mass) an inner section that bolts to the crank and an outer section that has the friction face for the clutch, the starter ring gear etc. A bearing in the centre allows the outer section to move relative to the inner whilst the drive from the inner to outer sections is transferred via 8 (I think, may have been more) hardened steel 'pins' of several mm diameter. To my amazement, ALL the pins had sheared - a clean break across the centre in each case. The indie and myself were left scratching our heads as to how on earth this had happened. The force required to snap all the pins at once would have torn the clutch apart (not to mention the internals of the gearbox) so it wasn't the previous owner dropping the clutch. There was also only minimal wear on the clutch friction plate (it went back in with the new flywheel - it was that good) so we were properly baffled - and really still are to this day!
The only explanation we could eventually think of, was that the bearing in the centre of the flywheel had seized which would have put the pins under a bending force, back and forward, every revolution of the engine. The pins then probably failed from fatigue stress over many months. The fact that, at idle, the engine used to shake the back of the car - almost imperceptibly, we'd always thought an engine mount was on the way out - but didn't once the new flywheel was fitted, also suggested this might have been the case.
Anyway, the car went back together fine, complete with a new flywheel and I went on my merry way. Now the big BUT (and why it's so important the OP listens to Henry-F's advice). About 2000 miles after my flywheel was replaced, my gearbox died - the bearing on the input shaft failed. Obviously, the failing flywheel had put it under huge stress and it was (unknown to me) only a question of time before it let go. The cost of even a second-hand 'box (many thanks to Porsch-Apart) plus fitting was several thousand £££s. Certainly did ruin my day....
A phone call to my local indie and a (very embarrassing) extraction of my car by trailer from my client's car park later, the car was on the ramp and the gearbox in the process of being removed. Later that day, the indie rang me to tell me he'd narrowly escaped serious injury as he removed the gearbox from the car. Apparently, the complete outer section of the flywheel - complete with clutch - literally fell off the back of the engine and barely missed hitting him as it crashed to the floor!
Looking at the remains of the flywheel the following day, it was very apparent what had happened. (The next bit's from memory, so forgive me if I have some of the minor details wrong). The flywheel is composed of 2 parts (hence dual-mass) an inner section that bolts to the crank and an outer section that has the friction face for the clutch, the starter ring gear etc. A bearing in the centre allows the outer section to move relative to the inner whilst the drive from the inner to outer sections is transferred via 8 (I think, may have been more) hardened steel 'pins' of several mm diameter. To my amazement, ALL the pins had sheared - a clean break across the centre in each case. The indie and myself were left scratching our heads as to how on earth this had happened. The force required to snap all the pins at once would have torn the clutch apart (not to mention the internals of the gearbox) so it wasn't the previous owner dropping the clutch. There was also only minimal wear on the clutch friction plate (it went back in with the new flywheel - it was that good) so we were properly baffled - and really still are to this day!
The only explanation we could eventually think of, was that the bearing in the centre of the flywheel had seized which would have put the pins under a bending force, back and forward, every revolution of the engine. The pins then probably failed from fatigue stress over many months. The fact that, at idle, the engine used to shake the back of the car - almost imperceptibly, we'd always thought an engine mount was on the way out - but didn't once the new flywheel was fitted, also suggested this might have been the case.
Anyway, the car went back together fine, complete with a new flywheel and I went on my merry way. Now the big BUT (and why it's so important the OP listens to Henry-F's advice). About 2000 miles after my flywheel was replaced, my gearbox died - the bearing on the input shaft failed. Obviously, the failing flywheel had put it under huge stress and it was (unknown to me) only a question of time before it let go. The cost of even a second-hand 'box (many thanks to Porsch-Apart) plus fitting was several thousand £££s. Certainly did ruin my day....
Edited by Ian_UK1 on Thursday 21st June 10:31
Edited by Ian_UK1 on Thursday 21st June 12:38
I'll bear that in mind. I'm going to pop into GT1 tomorrow and they said they'd take it for a test drive and see if they can diagnose the fault. Not having the best week. someone uses my bank account and completely cleans me out which is great, considering i was meant to be going on holiday on monday. -_-
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