Clutch Slippage - Troubleshooting prior to replacing

[ejaf]

Hi All,

2009 4DSD 5MT, 85K miles.

If I punch it in second or third, engine revs, and then the clutch finally grabs. I have yet to try the tests I've found on other threads here, but pretty sure that is the clutch going (duh).

Question is, before going and pricing just what it will cost, and who around me can do it (well), which is greater NYC, I am wondering if it could possibly be anything else other than the clutch going bad. The fluid "looks" clean, but even if it was dirty, that couldn't cause that behavior, could it? Or anything else to check for, prior to looking into a replacement?

Thanks in advance...

Eric

[bronsin]

Bleed the clutch cylinder before doing ANY work on the clutch which involves engine/transmission removal. :thumbsup:

Hydraulic clutches need to be bled once a year minimum in any case. I speak from vast motorcycle experience! I cant tell you how many posts Ive answered which go like Im In Alaska On A Trip And My Transmission Wont Shift! HELP!:eek:

Yes in MANY cases their neglected dirty clutch fluid PREVENTED THEIR TRANS FROM SHIFTING! Air/water in the lines can do the same thing.:thumbsup:

You DEFINATELY ought to be bleeding the clutch once a year just like you change your oil.:headbang:

And if you re having problems with the clutch and are considering having work done FIRST have the clutch bled. Its cheap and might just SOLVE YOUR PROBLEM.:bow:

[ejaf]

Will try this this coming weekend, and see if any improvement. Have to try this before anything, which was the advise I was looking for.

Thanks...E

[bronsin]

Good luck and let us know what happens!

[ejaf]

Just bled the clutch this morning.

Fluid didn't look dirty per se, but it definitely was cloudy.

The clutch seems to be grabbing somewhat better, but flooring it in third from 2000 RPM still causes the clutch to slip, until it catches up to the engine.

Time to look into replacement, unless any of you have other ideas. It's definitely drivable, though. Wondering whether it would take a while for the new fluid to clean out gunk on the clutch (hoping beyond hope).

Thanks all...

Eric

[Bluevitz-rs]

There's some free play in the pedal with it up all the way?

Does it only slip when hot or even when cold?

[ejaf]

Free play seems about the same, but will double check. How much free play should there be?

Didn't have anywhere to drive far to heat it up too much.

It seems as if it's slipping at 3000 RPM in third when I floor it, not 2000. Flooring it at 2000 doesn't cause the engine to race.

[dogsridewith]

How much does the clutch pedal come up before it starts to engage?

[ejaf]

Will report back after my wife is done with the car...she had to take it into the city.

Eric

[Bluevitz-rs]

The clutch is done. Change it.

[bronsin]

It seems as if it's slipping at 3000 RPM in third when I floor it, not 2000. Flooring it at 2000 doesn't cause the engine to race.


Indulging in this kind of behavior means that not only will there be problems with the clutch but many other things besides in the years to come! :thumbup:

[ejaf]

Bronson...thanks for your input...very helpful.

There is 1.5 inches free play, and clutch engages about halfway up. With parking brake applied, engine stalls when in third gear.

Bluevitz...I am tending to agree with you. I will look at replacement options.

I have been driving manuals my whole life, I'm not a spring chicken any more, and this is the first time I've burnt out a clutch.

It must be my driving style, as Bronson mentions...who would want to hit the gas in third when revving at 3000 RPM?

[bronsin]

Maybe...maybe not.

Yaris has the drive by wire throttle which Is notoriously hard to moderate off idle. My ECHO had a cable operated throttle...much better!

I'm a manual man all my life too until old age dictated an auto when I bought the Yaris. I couldn't BELIEVE the poor throttle response! That on or off throttle on the Yaris spells trouble for clutches.

To me.

[ejaf]

Thanks much for your explanation.

Last night, I applied the parking brake, shifted into 4th, and the engine stalled as well. It "seems" as if tests are showing the clutch is fine, but my brain is saying something else.

Thanks all for the input.

Eric

[ejaf]

Can this happen?

About a week into the bleed, it "seems" as if the slippage signs I was having is gone!

I know that it is possible that the clutch is on it's way out (I'm not the only one driving, I hadn't bled it until 85K, I have tried to teach how to dive a manual to my teenage daughter, etc. etc.), but how would bleeding it help so much?

At first try fter the bleed, it was still exhibiting the same behavior (flooring it in 3rd from 3500 rpm, the engine would rev), but now it seems, after a week, that that no longer occurs.

Is it possible the new fluid took a while to clean the plate? I'm baffled.

Eric

[Bluevitz-rs]

The hydraulic fluid has nothing to do with the clutch. It only pushes the release fork. If it was slipping it will slip again. If the clutch was ridden and has glazed it could make it intermittent. You can continue to use it until it doesn't grad at all and hope you don't wear the clutch disc down to its rivers or change it now and all you should need to do at most is get the flywheel resurfaced.

[CoryM]

Can this happen?

About a week into the bleed, it "seems" as if the slippage signs I was having is gone!



The clutch fluid is contained within a simple hydraulic circuit that consists of one piston (Master) pushing on a second piston (Slave) via fluid. The only way changing your clutch fluid could improve the clutch is if there was air in the system. Air will make it harder to shift, but not cause slipping. There is no theory, or practical experience I know of that would cause the clutch slipping to be affected by changing the fluid.

I would guess when you change your clutch, you will find the fingers on the pressure-plate are very worn. I think this is the cause of the erratic clutch feel that happens on these cars, but cannot say for sure. Take the car and in 3rd or 4th gear go from low rpm and floor it. If your engine RPM go up faster than your vehicle speed the clutch is slipping and should be replaced.

Good luck.

[dogsridewith]

Interesting.
+1 to posts here noting air in the system would tend to keep the clutch engaged...not make it slip.
And there's no real obvious or common way a worn slipping clutch would somehow fix itself.
But what if water water got into the slave cylinder the way air apparently does with some regularity on these. Causing rust and hanging up the slave piston so it doesn't fully retract and let the clutch disengage? Then the fluid change at your bleeding was just enough to progressively improve things a little in there.

[ejaf]

Thanks for the theory...I can only hope ;)

[bronsin]

HArd to get a handle on what is really going on with your clutch. :iono:

If you are ever in the south jersey area near Philly shoot me a message and let me look at it.:thumbsup:

It would help to post here maybe every week or so as it how its working.

If you decide to have the work done let us know. Likewise if all seems well with it.

Good Luck!:thumbsup:

[ejaf]

Gotcha...ty

[CoryM]

But what if water water got into the slave cylinder the way air apparently does with some regularity on these. Causing rust and hanging up the slave piston so it doesn't fully retract and let the clutch disengage? Then the fluid change at your bleeding was just enough to progressively improve things a little in there.

This is really the only possible (although highly unlikely) scenario for a flush to fix a slipping clutch. Why it is so unlikely is because the springs of the pressure-plate are quite strong, and will force the piston back as you release the pedal. So it would have to be enough rust build-up to pack solid behind the piston. This is pretty unlikely, and a flush probably wouldn't remove the packed in rust if so. If it were a rust lip, it would form past the piston's normal travel.

Cheers.

[dogsridewith]

Would just need enough "rust" packed in the very thin annulus between piston and cylinder. One of the clutch-bleed threads has discussion and photos showing some pretty ugly fluid removed.