I dunno, Really hard to tell how much lining ...
Shift into 2nd gear a bit sooner than you normally would, maybe while headed up hill.. and floor it - might slip, shouldn't if its good.
Of course starting off chatters would be a good indication of maybe it needs a new one.
Resting foot while slowly adding progressive pressure on it while in neutral, might hear bad sounds. Most should be quiet.

Thank you for your instruction, Mikie.

Average price ?
Saab 99 at an indie, 30 years ago ...less than $100
Saab 900 at an dealer , now ,$1,500 and more..
A Porsche could run into the thousands of $$$$ !
A VW beetle - $50 - when people were honest
Some of the old cars of yore(they were engineered to be serviced) - times were better - ...maybe less than $10..
As you can see, the prices vary, adequete infomation is necessary..and you will probably need handfulls of $$$$ !

Many of the symptoms of a bad clutch could also just be caused by a clutch that's out of adjustment. Cable-operated clutches need periodic adjustment as a normal maintenance service. Hydraulic ones should stay in adjustment, but may need to be bled periodically, and the master and slave cylinders can also go bad. If you experience hard shifting or symptoms of the clutch slipping, it'd probably be a good idea to have it looked at soon, as the clutch itself may be able to be saved by a simple adjustment or at least a less costly repair.

Cost to replace a clutch does, as Earthworm said, depend a lot on the vehicle. I'd say an average for a modern car is $300 - $500. A good transmission shop (find one that does a lot of work on manual transmissions) should be able to give you a pretty firm quote as to the price to replace the clutch on a specific make and model, so you can shop around if you find that you do need a new clutch.

Earthworm and cowboy, thank you very much for your instructions.

I visited several mechanics and found that the charge for replacing a new cluch varied greatly, from $400 in a small garage to $1200 in a Toyato dealer ( my car is Toyato corolla, 98, my location is San Francisco).

Really confused. What is a reasonable price? In one garage, I noticed that the price of a clutch kit is around $250, the other is labor. Why so much difference? Does replacing a clutch need so much tech that a regualr mechanic and an expert can make great difference?

I have another question, is it possible to diagnosis a worn out clutch just by a test driving, or needing disassembling?

Thanks a lot!

A properly adjusted clutch that still slips is ready for replacement. Careful driving can extend the life of a worn out clutch assembly...
The old Saabs used a manual adjustment, when we "ran out of adjustment", it was "Miller time" for us..

Look around, its the dealership owner driving the big Mercedes, living in the ten million dollar mansion..

The small shop owner drives a ten year old beater and lives in an ordinary "economy" house, but he works much harder for this...

Yes, and San Francisco is a high cost of living area, so your prices are going to be somewhat higher than elsewhere. Shops pay higher rent for their space, and have to pay higher wages to their mechanics. I'd say if you can get the clutch replaced for $400 in your area, that's a pretty good deal. Do some checking with your local Better Business Bureau, or ask friends about their experiences, to make sure the shop does good work. The cheapest repair you can find can wind up more costly in the long run if it's not done right. But paying a higher price doesn't guarantee better work, either. So it's just a matter of asking around and finding out if the shop is good.

The problem here is attempting to pick an automotive repair shop by pricing, on top of the fact that you are pricing something that as of right now, you don't actually need.

Would you choose a doctor by how much he charges?

If you need to dig a ditch, one guy says he will do it for $10.00/hr, and another says $100.00/hr do you automatically take the $10.00/hr guy who is going to show up with a shovel, and may take all month or do you get the $100.00/hr guy thats going to show up with a back-hoe and be in and out in one day?

You see tools, training, equipment, professionalism, all have a neccessary cost associated with them in order for a shop to do business. Competition between shops has "businessmen" utilizing different strategies on how best to attempt to be successful. By using price, you reward the guys that don't send their techs to schools for not sending them! You see, if they don't have the money coming in, then they of course cant spend it on things like that, because they don't have it in the first place! By using price first your reward them for not hiring the best technicians, for not purchasing the factory scan tools, or service information, or benefits for the employee's, and on and on.

As a consumer of course you are free to choose to take your car to anyone, and use whatever reasoning you want to apply for doing so. But that does not mean you should remain oblivious to the end result of such choices. When people use price first to choose a shop, they are telling me with their actions that it was a bad idea for me to buy the factory scan tool for their car, to go to more schools than the next shop, to continue to buy tools to service newer vehicles, etc. in order to be prepared to fix their car when it breaks.

Thank you very much, earthworm, cowboy and John.

To choose a garage, my first consideration is good work, but I can not afford the lexury of not taking price into account. I totally agree with cowboy, " The cheapest repair you can find can wind up more costly in the long run if it's not done right. But paying a higher price doesn't guarantee better work, either". That is why I come here and ask you experts for help, I would like to get some knowledge so that I may find a good mechanic at a reasonable price. I think I really learn something from you. I really appreciate it.

By the way, I am sorry that I make Johm creat the impression that "The problem here is attempting to pick an automotive repair shop by pricing', this is not my inclination at all.

No problem qinggaoi..

It's just important to consciously think about the fact that you really don't want to try to pick a shop by price first. If you find a great one, that has great prices, well, then GREAT! But in all reality whats important is that you find someone that is good at what they do, someone that you like and trust, and then support him/her with your business, and everything will just fall into place.