Manual transmission at stops

A couple of weeks ago you gave advice to someone with a manual transmission. I don’t remember what the problem was but you implied that you should not keep the clutch depressed while waiting for the light to turn green. Why? About the only time I take my foot off the clutch at red lights is when they are really long and my leg gets tired. Is this the reason?

Keeping the clutch depressed while in neutral tends to wear out a part called the throwout bearing.

Now a question for you: Why on earth do you normally keep the car in gear and the clutch depressed at stoplights? What is your reasoning?

I will occasionally do it if I am in a neighborhood where I don’t feel safe. I want to be able to drive away quickly if someone approaches the car. In addition, there might be a rare occasion where you hear tires screeching behind you and can pull away or pull to the side to get out of the way. In truck driving school and in the Motorcycle Safety Foundation’s Basic Rider Course, I was taught that in some situations, you might be able to benefit from having the vehicle in gear with the clutch disengaged, ready to go. You might never need it, but if you do, you will be glad you had the vehicle in gear. If, however, you are sitting in a car at a red light with cars on either side of you, you might as well take it out of gear and release the clutch. With a motorcycle there is no throwout bearing and there is almost always an escape route. If you are first in line at a red light or if you have a possible escape route to the side, there is a safety benefit to having your vehicle in gear with the clutch disengaged.

Keeping the clutch pedal pressed down to the floor for an extended period of time causes the release bearing to wear out prematurely. And why sit there with your leg extended in anticipation? It isn’t a drag race. Also if you get rear-ended and the car is in gear, you are more likely to get pushed even further than you normally would in case your foot lets the clutch slip.

I’ve owned and driven manual trans cars since Hector was a pup and have never worn out a TO bearing. Plenty of my driving is in a city and the surrounding suburbs with plenty of stoplights. If the wait is more than a half minute, I might let the clutch out with the trans in neutral but on the other hand, it is good to be ready to go when the light turns green. Don’t worry much about your TO bearing and enjoy the ride. The bearing will likely last longer than the clutch disk.

If you have a VW, the TO bearing is lubed by the trans fluid so with one of these you can worry even less.

I’ve owned and driven manual trans cars since Hector was a pup and have never worn out a TO bearing.

I agree. My current car’s original clutch has 176,000 miles and almost ten years of use. If the throughout bearing was so fragile, mine would have failed by now.

I really don’t think the throwout bearing takes much wear if the clutch is fully disengaged, i.e. all the way to the floor. What will wear one out is riding the clutch pedal, or resting your foot on the pedal, between shifts. I too have driven manual transmissions since I first started driving 37+ years ago and was taught to keep my foot on the clutch and the car in gear at stoplights. The only time I’ve had a throwout bearing go bad was in a truck that I shared driving with another guy who kept resting his foot on the pedal between shifts.

I learned in Northern New Jersey, by the way, so lots of stop-and-go and lots of stoplights.

I was always told to sit at lights with the vehicle in neutral, right foot on the brake pedal. In my day, driver’s ed was taught in standard transmission cars. I have never had to replace a clutch or throwout bearing on any car that I’d driven since (they were) new. I have replaced TO bearings and clutches on cars that others had driven, and abused by keeping their lfet foot on the clutch at lights. It drives me nuts to ride with someone who sits with the clutch to (or worse, near) the floor.

I have two friends who have over 300K miles on their six cylinder Chevy pickups with ORIGINAL clutches. They NEVER sit with a fot anywhere near the clutch pedal.

Worried about someone approaching the car and needing a quick get away? How long can it take you to put your car in gear anyway, and what kind of areas do yo drive in?

Thanks all for the infomation. It sounds like a 50/50 split on to depress or not to depress. I have never had a TO bearing go out on me onany of the manual transmissions that I’ve had. My 91 S10 was so good that I didn’t even have to use the cluch most of the time, even though it worked just fine. Lazyness on my part was the reason behind this. It had 126,000 miles on the orangial cluch when I sold it beacuse it didn’t have power steering. Have a Merry Christmas to all.

I had a Ford F150 for 21 years and replaced the TO bearing once only because the clucth went out.

Actually, Ranck, it’s the clutch plate that wears from slippage from resting your foot on the pedal. The throwout bearing is a thrust bearing that is at its fullest load when the clutch pedal is pushed all the way in. The pedal pushes a bifurcated lever (in must cars today the two are connected hydraulically) that pushes the ends of the spring loaded fingers radially arranged around the pressure plate. When the pedal is held in, the bearing is fully loaded, the outside “bifufcated fork bearing casing” held stopped and the other casing of the bearing spinning along with the engine. Remember that the pressure plate assembly is bolted to the flywheel and spins with the engine while the clutchplate slides on the transmission input shaft and is clamped against the flywheel when the clutch pedal is released.

The throwout bearing’s least wear condition is with the pedal released, In that condition it isn’t under heavy thrust load from the pressure plate fingers and both casings are spinning at the same speed.

Holding the pedal in is more wearing to the throwout bearing than putting the tranny in neutral and letting the pedal out. Holding the pedal in won’t guarantee that teh bearing will wear out prematurely, but it does increase the odds.

Regardless of the wear & tear caused or not caused, again, I think it’s pointless to sit there idling with your left foot extended to the floor, unless i’m at the front of the pack and can anticipate a short lived light in which case I want to be ready to get the car rolling.

jmw