What causes a hot spot?

[MS3MB]

So I was told that I have a hot spot on my clutch but I don't know that much about car yet lol so I dont really know what that means. First of all what causes a hot spot on a clutch to form. And what really does a hot spot mean?

Also I had a problem with my 2nd gear popping out and they said that it was due to some broken gear teeth. Here are some pictures they sent me

 

[MicaSp33d]

slipping your clutch on a hill to keep from rolling instead of holding with the brakes can cause hot spots

the flywheel is a dual mass flywheel and will most likely need to be replaced, the oem replacement are expensive. Many will tell you it can't be resurfaced, but it can and it may be hard to find someone to do it.

how many miles do you have?

 

[oaklandopen]

yea, that can happen to brakes as well, and you don't even have to take anything apart to see them

basically the metal has gotten sooooooo hot that the metalergy has changed and it doesn't work as well as it should. yea coulda been trying to stay still on a hill or starting out in 3rd from a stop, lettting the clutch out too slowly. any number of things that would inherently cause major heat

 

[gonerogue]

slipping your clutch on a hill to keep from rolling instead of holding with the brakes can cause hot spots....

From the wording, it sounds like just one incident can cause a hotspot. Is that what you're getting at?

 

[matsuda]

So I was told that I have a hot spot on my clutch but I don't know that much about car yet lol so I dont really know what that means. First of all what causes a hot spot on a clutch to form. And what really does a hot spot mean?

Also I had a problem with my 2nd gear popping out and they said that it was due to some broken gear teeth. Here are some pictures they sent me

It looks like you need a car with an automatic transmission.

 

[MS3MB]

It looks like you need a car with an automatic transmission.

Or this was my first manual and that was from learning. Especially since i went to an almost vertical hill I could see how i have these.

 

[gonerogue]

Or this was my first manual and that was from learning. Especially since i went to an almost vertical hill I could see how i have these.

Have you since learned to use the parking brake to start on steep hills?

 

[MS3MB]

Have you since learned to use the parking brake to start on steep hills?

Well I know how to use it but I don't need to use it anymore. I have figured out how to drive a stick

 

[SallySpeed3]

I don't think he was trying to imply that you can't drive stick. I use the e-brake when I have to. Lets face it, if you're on a steep hill, the second it takes for you to take your right foot off the brake and put it on the gas, you're gonna roll back an inch or two, regardless of how good of a driver you are.

 

[MicaSp33d]

From the wording, it sounds like just one incident can cause a hotspot. Is that what you're getting at?

it is possible, you can fry the clutch in one try if you wanted to ...

also, i wouldn't use the parking brake on hills, you'll never learn that way. It forces you to know your clutch well.

 

[oaklandopen]

it is possible, you can fry the clutch in one try if you wanted to ...

also, i wouldn't use the parking brake on hills, you'll never learn that way. It forces you to know your clutch well.

agreed. if the hill is steep enough i usually leave the brake pedal down, but put it in 1st and slowly engage the clutch until i see the rpms drop a little. then i back off just enough and stay there until either the light changes or im able to pull out into traffic. then as soon as i take my foot off the brake i can press the gas and the clutch engagement is right there almost immediately

but most of the time i take the route that doesn't include the steep hills where i would have to be stopped on them.

 

[gtlaw]

how many miles are on the car? what is being done about the broken gear teeth? how much is this going to cost, and is mazda covering any of this?

 

[gonerogue]

it is possible, you can fry the clutch in one try if you wanted to ...

also, i wouldn't use the parking brake on hills, you'll never learn that way. It forces you to know your clutch well.

Hmm, I've heard contrary for safety purposes. Most of my knowledge about driving stick comes from experience (not much) and reading Standard Shift. I don't think it is worth trying to use just your clutch in a city like San Francisco or down near Pike Place Market in Seattle.

 

[robin2660]

Just how much of this clutch-slipping does it take and, wouldn't you smell burnt clutch?

 

[matsuda]

Or this was my first manual and that was from learning. Especially since i went to an almost vertical hill I could see how i have these.

That could easily explain the clutch damage but not the broken transmission (gear damage).

 

[imac]

Hmm, I've heard contrary for safety purposes. Most of my knowledge about driving stick comes from experience (not much) and reading Standard Shift. I don't think it is worth trying to use just your clutch in a city like San Francisco or down near Pike Place Market in Seattle.

im with oakland and mica on this too. its not bad to know how to use the ebrake for starting from a hill, but its not something i do unless its really needed, like if someone is literally right on your ass or something. once you get used to the clutch in a car you should know where the catch point is on the pedal release, so like oakland was saying, you can bring it up to just before that point and as you're letting off the brake and going to the gas, letting it off that extra little bit keeps you from going anywhere and doesnt abuse the clutch.

 

[MS3MB]

Ya I don't use e brake anymore I can start fine from hills now it was just in the beginning I was kind of harsh. But ya mazda is fixing the tansmission after they declined the claim at first, they changed their mind from my annoyance. I was told today that it will take 4 weeks for the part to come in to fix my transmission

 

[meicalnissyen]

From the wording, it sounds like just one incident can cause a hotspot. Is that what you're getting at?

the hot spot means one area, or in your case three, have taken the brunt of the abuse. thats because the theorectically flat plates and disc are not truly flat when you add heat and axial pressure and speed differentials. during small periods of time you have a stick/slip/stick thing going on, during the stick phase, cooling takes place as the parts are actually locked up and motionless to each other. when it starts to slip again then the heat builds back up. this is commonly called chatter. with the harmonics of the situation added in, the "slip" and cooler "stick"happen in the same physical area of the disc, locally heating one area more than another. carry it far enough, and you get the metalurgical change in the crystal structure the other poster mentioned. checking is another, where a fine pattern of surface cracks appear, plain warpage will cause one or two highspot to form which obviously are always first to contact and make more heat