Symptoms of warped clutch/flywheel?

[Geomax]

saw a post earlier about someone experiencing a shudder when shifting. anyway, what would the symptoms be if the clutch plate or flywheel were "warped" (as someone put it)???

[The HACK]

Clutch and flywheels work by smashing two DISCS together. Brakes warp because the pads only contact a fraction of the surface of the brake disc at a time, hence irregularities in use or poor material may result in warpage. It's more likely the clutch is BURNT or slipping, when the contact surface of the clutch disc are worn smooth allowing the two clutch discs to spin past one another. Normally the symptoms would be higher revs at lower speed (i.e. launching from a stand still, the rev goes up, clutch is engaged but the car does not move) along with a foul smell some have described as crappy firecracker with a tinge of dead animal. Some smoke may be associated with it.

The shudder may be the syncro mesh struggling to catch up with the clutch plate.

[10chi]

I don't have any of those symptoms. I thought that it may have been due to the wet surface and wet leaves. However, I was just concerened that the DSC didn't light up when the tires normally slip.

[Geomax]

Hack - excellent reply. Thanks! Could you also explain what the syncro mesh is??

[Geomax]

[10chi]

yup. I am gonna try it again...the roads have dried up a bit.

[Sergio 323ci]

I've noticed that in my car, in heavy stop-go traffic, the clutch may begin to shudder if I release it slowly enough where too much heat builds up over a long period of time.

[njduce69]

you guys are all wrong, the shuddering is cause by moisture that builds between the two disc plates. Notice that this only happens when a the car is cold in the and b when it rains and you go thru a huge puddle

[Geomax]

I mean, aren't the plates sealed within a housing of some sort??

[The HACK]

Not the exact inner working of it. It's an interface between the clutch and the gearshafts that allow the gears to spin up as the clutch engages. On modern cars equipped with syncro mesh, you no longer have to "double clutch" to engage a lower gear since the syncro mesh will spin up the gears for you. Basically, on older cars in order to engage the gear you first have to put the car in neutral, engage the clutch to get the gears spinning (but not the driveshaft), disengage the clutch, put the gear selector in the proper gear, and then engage the clutch again to connect the flywheel to the gears and to the driveshaft. The syncro mesh eliminates the need to double clutch by spinning up the gears when you disengage the clutch, as well as provid a "mesh" like structure (this is the part I don't fully understand) that lessens the impact of the clutch engagement onto the gear and driveshaft. So when the engine/flywheel speed is vastly different from the speed of the gear (for example, launch from dead stop), you get the shudder/lurch when the syncro mesh can't catch up with your clutch and had to disengage/reengage or release the spooled up torque (at least that's the way I understand it). On older cars sans the mesh, if you do not get the engine speed correctly on a launch it will simply stall. On newer cars you get the lurch.

I don't know exactly when syncro meshes are introduced in manual cars, but I've never driven a car without a syncro mesh so I can't double clutch nor do I know what it feels like. If you can find the proper inner workings of a syncro mesh please let me know, I'd like to understand a little more about it as well.

[Kaz325iT]

[The HACK]

Although I'm not sure if it's slippage. The engine management software senses an impending stall and rapidly varies the engine speed and fuel injection to prevent the stall. If it's actually slipping you'll hear a squeak from metal slipping by metal. Next time watch your engine speed rise and fall along with the shudder...At least that's what I think it is.

[down speed. -Kaz325iT]

In any case, I'm not worried about it.

[The HACK]

of metal vs. metal. The shudder can also be from the drop in engine speed...Below certain rpm the rods and weights will no longer be balanced in their travel and will cause the engine to shake from side to side. I can't explain it but I'm fairly certain it's not clutch slippage. If it is I'm in for a very short clutch life. :(

[Kaz325iT]

It doesn't sound intuitive at first, but all the gears inside a manual transmission are meshing ALL THE TIME. In fact, when you 'shift gears,' there is no physical 'shifting' of gears at all. Whether its a synchro or not ('crashbox'), the part that moves when you shift are the 'dog rings'. Where synchros come into play is that they're essentially a clutch that allows the dog ring (which is permanently attached to rotate with the output shaft) to accelerate (or decelerate) the gear its about to engage (which its sharing the shaft with, but the output gear SPINS FREELY on it instead).

I found it very fascinating and answered all my questions about manual trannies when I read about this stuff.

[The HACK]

So I was somewhat correct in principle but not in actual application. It's nice to know how exactly it works. Time to go look up how a torque converter works. :)

[10chi]

well thats a little more comforting than my clutch slippage. Is this moisture build up bad? How can I remedy this problem?

[njduce69]

clutch plates are not sealed bacause then they would overheat, this moisture that builds is not bad for the clutch its normal.
duce69

[Unregistered]

I've been having issues with the shuddering. When I'm letting go of the clutch in first, it shakes the whole entire car for a split second then finally gets into gear. Does this mean there is moisture causing the problem or is my clutch slipping? I live in MN and it's always cold now that it is basically winter. During the summer I would rarely have the shuddering problem, but now it's literally every time I am letting go of first gear.

you guys are all wrong, the shuddering is cause by moisture that builds between the two disc plates. Notice that this only happens when a the car is cold in the and b when it rains and you go thru a huge puddle