[champignon]

Originally Posted by ajvdh

He's wrong. You can wear out a throwout bearing. I bought a used E46 330 some years back with 60k miles on it. I don't idle in gear with the pedal down, but the previous owner apparently did. I could always feel a little pulsing through the clutch pedal. By 90,000 miles it was alarming, so I took it to my independent BMW shop. He said the throwout bearing was so worn it was starting to weld itself in place, but the clutch itself still had plenty of meat left on it.

OK, so what does it cost to replace this "throwout bearing?" 90K miles is a lot of service for a part in a car (other than maybe the engine). And how long would this part last if the previous owner didn't "idle in gear with the pedal down?"

No car parts I am aware of last forever.

[ajvdh]

Originally Posted by champignon

OK, so what does it cost to replace this "throwout bearing?" 90K miles is a lot of service for a part in a car (other than maybe the engine). And how long would this part last if the previous owner didn't "idle in gear with the pedal down?"

No car parts I am aware of last forever.

It requires the same steps as replacing the clutch, so several hundred dollars just in labor.

Did you miss the part above where I mentioned the clutch itself was still fine? if you're not abusing the equipment, the TO bearing should last at least as long as the clutch.

As long as you're asking: IME 90k miles is for a TO bearing/clutch in a regular passenger car is poor. You should be able to get well over 100k miles out of a clutch/bearing in normal daily driving. My E30 managed about 200k. Hell, I my turbo-ed E36 M3 time trial rat still had the original clutch in it when I sold it to a friend of mine who turned it into a wheel-to-wheel race car. He did replace it at 140k, but that's 'cause he treated it as preventive maintenance when replacing the motor he blew with a money shift.

[champignon]

Originally Posted by ajvdh

It requires the same steps as replacing the clutch, so several hundred dollars just in labor.

Did you miss the part above where I mentioned the clutch itself was still fine? if you're not abusing the equipment, the TO bearing should last at least as long as the clutch.

As long as you're asking: IME 90k miles is for a TO bearing/clutch in a regular passenger car is poor. You should be able to get well over 100k miles out of a clutch/bearing in normal daily driving. My E30 managed about 200k. Hell, I my turbo-ed E36 M3 time trial rat still had the original clutch in it when I sold it to a friend of mine who turned it into a wheel-to-wheel race car. He did replace it at 140k, but that's 'cause he treated it as preventive maintenance when replacing the motor he blew with a money shift.

Your estimation is probably no better than anyone else's. If what you are saying is that the part should last 100,000 miles, but someone who drives in a manner that you deem to be inappropriate, might only get 90,000 miles out of the part, then for anyone with any sense of statistics would say you are well within the margin of error and have by your own "estimation" failed to prove your point.

[David.m]

Originally Posted by champignon

Your estimation is probably no better than anyone else's. If what you are saying is that the part should last 100,000 miles, but someone who drives in a manner that you deem to be inappropriate, might only get 90,000 miles out of the part, then for anyone with any sense of statistics would say you are well within the margin of error and have by your own "estimation" failed to prove your point.

Your missing the point, with proper driving the throwout bearing (thrust bearing down here) will out last your clutch and I have had one clutch last 230K km. On another car I bought 2nd hand the bearing went when the clutch was half worn and of course it's smart to replace both at the same time. So the point is would you rather have a cheap bearing dictate when you need to spend $ on clutch replacement (a clutch that could have many miles of life left in it) or simply replace the bearing once your clutch has had it's day.

[champignon]

Originally Posted by David.m

Your missing the point, with proper driving the throwout bearing (thrust bearing down here) will out last your clutch and I have had one clutch last 230K km. On another car I bought 2nd hand the bearing went when the clutch was half worn and of course it's smart to replace both at the same time. So the point is would you rather have a cheap bearing dictate when you need to spend $ on clutch replacement (a clutch that could have many miles of life left in it) or simply replace the bearing once your clutch has had it's day.

I'm not missing the point at all.

Certainly there are situations where people wear out clutches in record time, people who tune their engines and then treat the transmission with anything but respect. I am assuming that you have also read posts on forums made by people complaining that their clutch needed replacement after less than 30,000 miles.

Forgetting about examples such as that, the more typical examples would be for clutches lasting anywhere from maybe 60,000 miles on upwards to what you cite in your own case, 230,000 km (roughly 142K miles). The problem with this sort of "data" is that it is anecdotal. Most people don't buy a manual transmission car when it is new and keep it for long enough to accumulate 142,000 miles; the car has long since been traded in. Most people who own a car with over 100,000 miles on it, are the 2nd, 3rd, 4th, 5th, or 6th owners. This means that the transmission components have wear from multiple people and multiple driving styles. Different cars also have different transmissions composed of differing parts, that wear at different rates, regardless of how they are driven.

I'm a fossil and I've owned a huge number of cars, from many different brands, and only one of those cars had an automatic transmission. I'm talking about Toyotas, Lexuses, Acuras, Hondas, Subarus, VWs, BMWs, and a Porsche (which I still own), most of which were bought new. Of these, I owned one BMW for 10 years, my longest personal ownership of a car bought new. The only one of my cars I have ever replaced a clutch on was the 2000 Z3M Coupe I bought 3.5 years ago with almost 60K miles on the clock, which was a single owner car, owned by a sedate senior citizen female when I bought it. I replaced the clutch within 1000 miles of having bought the car, so it was not my driving that did it in.

Bottom line is that I don't think that the data is available out there to categorically state that anything other than blatant abuse of the transmission leads to provable early failure of the clutch or other components in a MT car. There are few single owner cars that get clutch replacements, and those that do are going to be a mixture of abused vehicles and a few rare ones that are owned for a long time and driven lots of miles by a single owner. The rest of the vehicles don't show wear from one driver, they show wear from multiple drivers. Drawing conclusions from this sort of information is just not going to produce reliable results, regardless of what are your own, personally limited, observations.

[RAM_F30_F87]

https://www.etsy.com/listing/2390588...hoCbfkQAvD_BwE

[ajvdh]

Originally Posted by champignon

I'm not missing the point at all.

Certainly there are situations where people wear out clutches in record time, people who tune their engines and then treat the transmission with anything but respect. I am assuming that you have also read posts on forums made by people complaining that their clutch needed replacement after less than 30,000 miles.

Forgetting about examples such as that, the more typical examples would be for clutches lasting anywhere from maybe 60,000 miles on upwards to what you cite in your own case, 230,000 km (roughly 142K miles). The problem with this sort of "data" is that it is anecdotal. Most people don't buy a manual transmission car when it is new and keep it for long enough to accumulate 142,000 miles; the car has long since been traded in. Most people who own a car with over 100,000 miles on it, are the 2nd, 3rd, 4th, 5th, or 6th owners. This means that the transmission components have wear from multiple people and multiple driving styles. Different cars also have different transmissions composed of differing parts, that wear at different rates, regardless of how they are driven.

I'm a fossil and I've owned a huge number of cars, from many different brands, and only one of those cars had an automatic transmission. I'm talking about Toyotas, Lexuses, Acuras, Hondas, Subarus, VWs, BMWs, and a Porsche (which I still own), most of which were bought new. Of these, I owned one BMW for 10 years, my longest personal ownership of a car bought new. The only one of my cars I have ever replaced a clutch on was the 2000 Z3M Coupe I bought 3.5 years ago with almost 60K miles on the clock, which was a single owner car, owned by a sedate senior citizen female when I bought it. I replaced the clutch within 1000 miles of having bought the car, so it was not my driving that did it in.

Bottom line is that I don't think that the data is available out there to categorically state that anything other than blatant abuse of the transmission leads to provable early failure of the clutch or other components in a MT car. There are few single owner cars that get clutch replacements, and those that do are going to be a mixture of abused vehicles and a few rare ones that are owned for a long time and driven lots of miles by a single owner. The rest of the vehicles don't show wear from one driver, they show wear from multiple drivers. Drawing conclusions from this sort of information is just not going to produce reliable results, regardless of what are your own, personally limited, observations.

I find it interesting that you had the choice of simply saying, "Huh, I learned something about how cars actually work," but instead chose to dump a wall o' text, none of which was germane the specific issue, after admitting you don't even know how a clutch works, or can fail.

Let's recap. You originally posted:
I have been told by at least one service adviser that the admonition to "never idle in gear with the clutch depressed" isn't based on anything. When the clutch is depressed there is no engagement of the gear and no wear going on, with the possible exception of the spring that suspends the clutch pedal in place. I'm not a mechanic so I can't confirm any of this.

While some "service advisors" are mechanics, most, IME, are not. Guess what? You're not the only fossil on here, and this particular fossil has built engines and race cars. I've even replaced clutches and throwout bearings (first one about 40 years ago), so let me give you a simple explanation:

When the clutch pedal is up, there's no load on the T/O bearing. When you do depress the clutch, there is load on the T/O bearing. Load = wear. The longer you keep the pedal depressed, the more wear there is. The bearings are designed with wear in mind, but also the anticipation that the car will be in neutral with the clutch released when idling for extended periods. Habitually not doing so is abuse, and will cause premature wear and possible failure.

You wanna chance it with your clutch? Go right ahead, but please tell any anticipated buyers of one of your cars that you do so, so they factor the possibility of a clutch job into the price.

[champignon]

Originally Posted by ajvdh

I find it interesting that you had the choice of simply saying, "Huh, I learned something about how cars actually work," but instead chose to dump a wall o' text, none of which was germane the specific issue, after admitting you don't even know how a clutch works, or can fail.

Let's recap. You originally posted:
I have been told by at least one service adviser that the admonition to "never idle in gear with the clutch depressed" isn't based on anything. When the clutch is depressed there is no engagement of the gear and no wear going on, with the possible exception of the spring that suspends the clutch pedal in place. I'm not a mechanic so I can't confirm any of this.

While some "service advisors" are mechanics, most, IME, are not. Guess what? You're not the only fossil on here, and this particular fossil has built engines and race cars. I've even replaced clutches and throwout bearings (first one about 40 years ago), so let me give you a simple explanation:

When the clutch pedal is up, there's no load on the T/O bearing. When you do depress the clutch, there is load on the T/O bearing. Load = wear. The longer you keep the pedal depressed, the more wear there is. The bearings are designed with wear in mind, but also the anticipation that the car will be in neutral with the clutch released when idling for extended periods. Habitually not doing so is abuse, and will cause premature wear and possible failure.

You wanna chance it with your clutch? Go right ahead, but please tell any anticipated buyers of one of your cars that you do so, so they factor the possibility of a clutch job into the price.

Thank you for educating us drivers who don't work on our cars. I am oh, so impressed with your keen mechanical wisdom.

For the record, I don't idle with the clutch depressed for significant periods of time. I also do relatively little congested city driving, and as a result, would not have the opportunity to do so, even if I wanted to. 90% of my driving is on the open road. And as I said, in many decades of driving I have never come close to personally wearing out a clutch. I have also never worn out a set of brake pads or other related components.

I merely reported what I have been told by service writers, and no, I don't know which of them actually work on cars.

Relatively few car owners own any car for long enough to personally wear out a transmission or any of its components; that's a simple fact and easily verified by looking at how long the average driver will own any car. Any discourse about what happens at 60 or 80,000 miles, when it "should" happen at 140,000 is, however, irrelevant to most people reading these forum postings, since they won't own the car long enough to suffer or to benefit anyway.