Just bought a 2008 Hatchback Manual Tranny and it shifts really strange

[attrapereves]

Originally Posted by CoryM

Yep, the Yaris clutch is probably (IMO) the worst part of the car. The slow throttle-body doesn't help much either. Nor does the engine being so quiet, and easy to stall. My clutch is now broken from driving for 3yrs on R-comp tires: Imagine what you have, but the engagement point changes at random. Sometimes it engages close to the floor, sometimes near the top. I'll be doing the clutch soon......

Interestingly enough my clutch isn't damaged from launching hard, but from tire slippage then biting HARD in corners. I think the previous owner took some life out of it too. I'm curious to see what a Luk clutch will do for the feel of the clutch because I'm sure not going to try an OE one again.

Can you explain what you mean about killing the clutch from tire slippage?

The clutch is the worst part of the Yaris. My previous Chevy Sonic (which had an issue with grinding going into 2nd) was light years better than this Yaris clutch.

[CoryM]

Originally Posted by attrapereves

Can you explain what you mean about killing the clutch from tire slippage?

It's not the slipping that hurts it, it's the sudden traction afterwards. I daily-drive (and autoX) on DOT race tires. The raw grip of these tires is far beyond what "street" tires can do. So: going around a corner hard, gas pedal to the floor to pull the car out of the corner, the inside tire spins due to weight-transfer/body-roll, then bites very hard as the weight goes back onto the inside tire. This causes a shock to the clutch similar to if you were to let the clutch out very abruptly. This usually wears/breaks the torsional springs in the clutch disc, which are there to soak up shock loads and vibration.

It's going to be about a month before I get a chance to do my clutch, but I am curious to see what it's going to look like

Cheers.

[attrapereves]

Originally Posted by CoryM

It's not the slipping that hurts it, it's the sudden traction afterwards. I daily-drive (and autoX) on DOT race tires. The raw grip of these tires is far beyond what "street" tires can do. So: going around a corner hard, gas pedal to the floor to pull the car out of the corner, the inside tire spins due to weight-transfer/body-roll, then bites very hard as the weight goes back onto the inside tire. This causes a shock to the clutch similar to if you were to let the clutch out very abruptly. This usually wears/breaks the torsional springs in the clutch disc, which are there to soak up shock loads and vibration.

It's going to be about a month before I get a chance to do my clutch, but I am curious to see what it's going to look like

Cheers.

Question about that. I was teaching my wife how to drive a manual today and once or twice she accidentally revved it to 4000rpm, then launched the car screeching the tires. I'm assuming this wears the clutch significantly?

Also, sometimes when I shift into 2nd my car will jerk a little bit. Does this jerking cause clutch wear?

[CoryM]

Originally Posted by attrapereves

Question about that. I was teaching my wife how to drive a manual today and once or twice she accidentally revved it to 4000rpm, then launched the car screeching the tires. I'm assuming this wears the clutch significantly?

Also, sometimes when I shift into 2nd my car will jerk a little bit. Does this jerking cause clutch wear?

Heh. Teaching people to drive manual is fun huh?

It's definitely not great for the clutch but, so long as the clutch is in good shape to begin with, not going to kill it while she learns. If you weren't smelling burnt clutch (strong, acrid smell that lingers), you aren't wearing the clutch too badly. If she were to continue to drive like that you would see reduced clutch life but it should be fine while teaching her. It takes time to get smooth.

Jerking should not cause wear of the friction surface, but will cause minute wear of the parts of the clutch that are there to absorb the shock loads. Nothing to worry about as you will always get the occasional poor shift. The clutches are designed with this in mind, and have a mechanism to deal with small shock loads. That being said, the smoother you can drive the more life you will get out of nearly every part of the car.

End of the day, the Yaris is hard on clutches. You need to ride the clutch a fair bit to get going, and with the poor pedal feel it can be hard to be smooth on shifts. I wouldn't worry much as the clutches still last a long time in these cars even with that. Mine is only broken because I am subjecting it to abnormally high shock loads from the race-tires. I am a mechanic though so repairs are cheap/easy .

Cheers.