how to test a manual car for a bad clutch?

Discussion in 'The Garage' started by BlahBlahYouToo, Jun 10, 2010.

  1. BlahBlahYouToo

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    going to check out a used STi.

    i've never driven a car with a worn clutch so i don't really know how it feels.
    i've heard things like, if the tach is increasing but the speedo isn't. or let the clutch out slowly in top gear and if it doesn't stall.

    any other tips?
     
  2. amdhunter

    amdhunter Lifer

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    I'd usually check by going to 25MPH, then going to the highest gear and accelerate enough to see if it slips a bit (but ask the sellers permission first, and explain to him what you are doing.)

    I'd also try and get a colder start to feel if the synchros are acting up (my RX-8 has a notchy 3rd when its cold, my Jetta also had it in 3rd, but worse.) I'd also do a (graceful) engine brake to see if the clutch can slow the car down if needed.

    Listen for squeaky pedal/mechanics.

    Make sure the car can climb a hill in 1st without any extra gas.

    I am a n00b though when it comes to these things...but I am sure just driving for a few minutes can give me some indication of bad vs good clutch.

    Sidestory Edit: I remember when I was looking at a 2006 STi I met the coolest fucking kid salesman who tried to convince me to purchase the car.

    I didn't buy it because I couldn't drive stick, and I told him I was going to break the car if I bought it -- he looked at me dead in the eye and said "there's no fucking way you are going to destroy this clutch, and told me how the car had enough torque to make up for any mistakes I might make."

    I had no idea what he was talking about then...lol
     
    #2 amdhunter, Jun 10, 2010
    Last edited: Jun 10, 2010
  3. PricklyPete

    PricklyPete Lifer

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    Tree test. Inch the car up to a tree until the bumper is resting on it. Put it in Gear and if the car stalls immediately once you let up on the clutch...then the clutch is good. If the car does not stall...or takes a while to stall...the clutch has some major slippage.

    Of course you wouldn't want to do this on a new car...but a new car...or even close to new wouldn't have a worn clutch.
     
  4. JulesMaximus

    JulesMaximus No Lifer

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    Be careful with those cars. They are frequently modded and raced then the guy takes the mods off when he sells the car returning it to stock appearance.
     
  5. overst33r

    overst33r Diamond Member

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    Accelerating in the highest gear at low rpm will not be enough. My friend and I bought a car in Atlanta, where the clutch was fine. Then burned up on the way home.

    If you let out the clutch in top gear you won't couple for at least 20 feet. That wouldn't really tell the condition of the clutch, but moreso the torque of the engine.

    It's a crap shoot in my experience, unless you have prior experience of what a new clutch feels like in the same car vs an old one.
     
  6. speedy2

    speedy2 Golden Member

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    E-brake would work just as well as a tree would. And not scratch any paint.
     
  7. halik

    halik Lifer

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    3rd gear WOT from standstill, you should see the rpms shooting up.
     
  8. JulesMaximus

    JulesMaximus No Lifer

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    Yeah, if I was with you on a test drive and you said you wanted to park my car against a tree to test the clutch I'd tell you to get the *** out...test drive over.
     
  9. ichy

    ichy Diamond Member

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    It would never buy a used STi. The person who bought that car probably drove it HARD, there's potential for all sorts of issues.
     
  10. spidey07

    spidey07 No Lifer

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    I was always taught to try to start off in 4th or 5th gear. If it doesn't slip unevenly and the rpms don't jump then it's perfectly fine.
     
  11. BlahBlahYouToo

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    it's a stealership.
     
  12. JulesMaximus

    JulesMaximus No Lifer

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    Right, so the original owner took the parts off before he traded it in.
     
  13. ViviTheMage

    ViviTheMage Lifer

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    Safe assumption. Shit ,as long as it doesn't slip it's fine ... no REAL way of testing it, at least that I know of.
     
  14. cheezmunky

    cheezmunky Senior member

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    I bought my 05 having driven a manual about 3 times before that. I've put about 20,000 miles on it since then and haven't had a problem yet. It's true for the most part as long as you don't go around dropping the clutch everywhere
     
  15. Zargon

    Zargon Lifer

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    so?

    mod - de-mod doesnt make it a shitty car......

    it being at a dealer it has a better chance of being on good shape, because it might off lease, and if any random crap is missing they can easily source the parts for cheap
     
  16. hanoverphist

    hanoverphist Diamond Member

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    i tested the clutch in my truck when i bought it, seemed good. no slips, jumpy starts or anything. the clutch blew in 5 months, hehe. ive been driving manual trans for decades, ive never had a clutch not outlast the vehicle. except for my old 61 scout. the guy i bought it off of replaced the slave cylinder with a mid 80s datsun cylinder and didnt have it in correctly, so it wore a channel down the side of the cylinder. i found out he did that due to the lack of new or rebuilt parts for that truck.
     
  17. Zenmervolt

    Zenmervolt Supermoderator<br>The Garage<br>Elite member

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    Very few clutches actually slip unless they are ridiculously, embarrassingly trashed. And with modern, self-adjusting hydraulics, even the friction point doesn't really change over the life of the clutch. The old "engaging high" telltale sign doesn't work so well anymore.

    One thing to look for though is whether the clutch if stiffer than normal. As the friction material wears down, the pressure plate has to stretch out further to keep the clutch pushed up against the flywheel and this can make the fingers a little sticky. So a clutch that is nearing the end of its life will tend to have more of a "break" to it. That is, it will take a little more effort to get started and then pedal effort will decline as just after the initial movement.

    Frankly, I'd have a shop look at it and evaluate it. For around $100, having an independent shop check the car out can save you a lot of hassle down the road.

    ZV
     
  18. overst33r

    overst33r Diamond Member

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    What shop do you know that will drop the tranny on an AWD vehicle for $100?
     
  19. amdhunter

    amdhunter Lifer

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    I did the same with my GLi, except I NEVER drove a manual before. A friend had to come pick me up at the dealership to drive me home.
     
  20. joesmoke

    joesmoke Diamond Member

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    the redline dump, nothing more nothing less
     
  21. The Stigenator

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    They way I was taught was this:

    1. Pull E-brake
    2. Put in 2nd gear *in some cars 2nd gear wont work, so try first gear then)
    3. Release clutch slowly, if the car starts moving (then clutch is bad), if the car shuts down then clutch is good (remember no gas pedal to be used).

    Sometimes the slipping happens at higher speed, but frankly if it slips it will slip at lower speed too.

    Remember higher the mileage on the clutch, its not going to shut down that easily, but if you find the car is running without gas pressed and is in gear, that clutch is shot.
     
  22. overst33r

    overst33r Diamond Member

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    See if the car has a V8, your theory is null.
     
  23. spidey07

    spidey07 No Lifer

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    LOL! So true. I'll happily move the car with the parking brake engaged.
     
  24. angry hampster

    angry hampster Diamond Member

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    Came in here to post this. It'd definitely let you know where the weak spots are.
     
  25. The Stigenator

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    Actually it still work on a V8. Remember no throttle.

    Yes its got more torque, but the fact is that if it slips it will show up if it has more torque at idle. Slipping occurs under conditions when torque is applied (when the mating surfaces are getting together). Actually you wont see it as easily on a measly 2-3 cylinder underpowered boat.