After close to 10 years of driving, only recently did I hear that it was bad to fully depress both the clutch and brake pedals while idling in a manual-transmission car. Usually when I come to a stoplight, not only to I downshift on approach (say from 3rd to 2nd gear), but once I’ve stopped, I shift into 1st and leave the clutch in while keeping my foot on the brake. No neutral or emergency brake for me!
Am I slowly killing my car? If so, what, precisely, am I doing to it?
I should probably shut up, because I know 3 year old girls who know more about cars than I do, but lack of knowledge has never stopped me before.
Anyway I was told not to ride the clutch, which I was told included staying in gear at traffic lights. But then a friend of mine who DOES know about cars said it’s fine at stop lights, since the car is not in motion – that the clutch wearing down happens in those periods between being fully depressed and not depressed at all (damn those bipolar clutches). He said that the in-between phase is where the wear happened so it’s fine to hold the clutch down, especially when at a complete stop.
But I look forward to hearing what real car experts have to say on the matter.
You have to distinguish between two different types of wear.
The clutch facing wears whenever the clutch is slipping, which would be every time you get rolling from a stop by slowly taking your foot off the pedal, or if you’re holding yourself on a hill by modulating the pedal.
The clutch throwout bearing wears whenever you have your foot on the pedal (the throwout bearing presses against some “fingers” in the clutch mechanisnm to hold the clutch disengaged).
So at a stop sign, with your foot on the clutch pedal, there’s wear on the throwout bearing, but none on the clutch facing (since the throwout bearing is holding the clutch completely disengaged).
If you slip the gearshift into neutral and take your foot off the clutch pedal, there’s no wear on either the facing or the bearing (since the clutch is fully engaged).
When you start rolling, there’s wear on both the bearing (your foot’s on the pedal) and on the facing (since you’re slipping the clutch for a smooth start).
If you’re holding yourself on a hill by slipping the clutch, there’s wear on both the facing and the bearing. Lots of wear on the facing, I might add.
Here’s what the (hilarious) Car Talk guys have to say about this.
Thanks for the responses. The links are great! According to the Car Talk guys, it looks like my answer is “Yes, I am slowly killing my car.” Damn.
If I want mine to last a really long time (& they do) I only touch the clutch pedal when I want
to use the clutch. Even resting your foot on it can activate it.
Mini hijack-ette…is it really important to push the clutch the whole way in when disengaging it or changing gear? Mine has a lot of travel in it, and I really have to stretch my leg to get it pushed that extra couple of inches all the way to the floor. (I know, I could move my seat forward, but that causes me other problems).
If the car isn’t trying to creep forward when you’re stopped and you aren’t grunching the gears when shifting, I’d say don’t worry about it.
Now, wait just a minute. I started a very similar thead quite a while ago, and things didn’t seem nearly as cut and dried. It’s just about lunchtime, so the hamsters are wheezing, so I’m not going to search for it, and I can’t find it at the Car Talk website (I’m finding mostly make’n’model survey results–LAME!), but I remember the advice from Tom and Ray (or maybe from a Doper) that you’re unlikely to wear out the throwout bearing before you wear out the clutch, and if you have to replace the clutch, they will replace the throwout bearing at that time. (Sorry 'bout the lack of cites!)
You are correct, Podkayne. It is very unlikely that you will wear out a release bearing prematurely unless you make a habit of resting your foot on the clutch pedal. Keeping it down at the light, while I don’t recomend it, isn’t going to hurt it.
And you are also correct that when you replace a clutch, any mechanic worth his/her salt will replace the release bearing and pilot bushing/bearing. If they don’t want to or say don’t bother, find a new mechanic.
Well, I know this is 1 piece of anecdotal evedence, but I put 120k miles on my old Civic’s clutch and it’s still functioning as good as new…and I only put it in neutral at a stop if I was in a non-moving traffic jam.
Jman
You are driving along…you need to stop…you remove your foot from the accelerator and hit the breaks til the car slows to a stop…shortly before stopping, you pop the tranny in nuetral from whatever gear it was in…and in doing so, you never even appy the clutch (yes…you can do it). So, here you are, waiting at whatever intersection, in nuetral, having never applied the clutch. Depress the clutch pedal when traffic in front starts to roll…or if your are the first car, depress the clutch when the light turns to stop traffic coming the other way.
This is how I have always operated. Doesn’t this make a ton of clutch-friendly-sense?
Oh, one more thing, DarrenS; if you’re reasonably handy with tools, you might try adding a block to the clutch pedal. On an RX-7, I ended up bolting blocks of wood to the clutch and brake pedals so that I could sit a bit further from the gas pedal (my right leg was uncomfortably bent). It’s amazing what 3/4 inch will do.
The blocks were 3/4 wood, screwed to the pedals; I added a thin metal plate to the face with a slight overhang so I could slip the rubber pads onto them.
I thought that with modern manual transmissions you don’t damage the throwout bearing at all by keeping the clutch all the way in. I remember Tom and Ray discussing this and saying the advice was still being given because many people don’t have modern transmissions yet. Am I all wet?
Clutches have changed very little in 20-30+ years… or at least since Hydraulically operated clutches came online. Transmissions certainly have changed, but clutches by and large are the same.
Regardless, if you keep you clutch in at a light you are not “hurting” anything.
No, Telemark, you’re not all wet: http://cartalk.cars.com/Columns/Archive/1997/August/06.html
Seems the difference lies in being a “self-adjusting” clutch, whatever that is. Seems that with these newer types of clutches, the throwout bearing is always being brought into play.