Slipping clutch...solution premium gas?

rav4
clutches

#1

I have a 97 Toyota RAV4 with 110,000 miles. The clutch is slipping, which I expected about now, and I’m in the process of getting quotes to replace it. In the meantime my service station did not have regular or ultra gas in the pump this morning so I used premium and lo and behold…NO SLIPPING CLUTCH.



Since gas is not gas is not gas…can anyone recommend a permanent solution to my clutch issue (which may not be a clutch at all?)


#2

These things are TOTALLY UNRELATED…Just a coincidence. OR…The clutch wasn’t slipping…but some other problem


#3

If your clutch is worn and slipping, the type of gas you put in the tank won’t make any difference. There is NO connection.

Please define “slipping.” What happens, exactly, and when? I don’t expect my clutch to start slipping at 110K miles.


#4

Manual clutch, the engine races when I try to put it in gear, when shifting to any gear it takes a few seconds for my baby to grab the new gear rather than the previous smooth shift, acceleration.


#5

Set the parking brake, put the transmission into 5th gear, give the engine a little gas and let the clutch out slowly. If the engine stalls, the clutch isn’t slipping. If the engine doesn’t stall you need a clutch, and the gasoline you put into the tank won’t make any difference.

By the way, premium gas won’t fix flat tires, either.


#6

Well, that sounds like a slipping clutch. Premium gas has NOT fixed it.


#7

You’re right! I air my tires with regular gas.

Sometimes, what you Toyolover have experienced is called coincidence.


#8

All joking aside (That was fun, wasn’t it?), it may be more of a matter of there being a delay of engagement. If the clutch is hanging up somewhere, it might be thought of as slipping.
A clutch can last a lifetime if the engagement is done at minimum speed difference between the engine and transmission, at minimum load.


#9

Thank you for your genius. The car immediately stalled out, but you knew that, didn’t you? Can you suggest what might be the problem, since my mechanic wanted to simply replace the clutch? And I’ve now driven through the premium gas to see if, indeed, I was mistaken, and the problem has returned.


#10

its definately the clutch thats getting worn,but driven gently it could go on for quite a while! the premium gas theory is totally un-related!110,000 miles is pretty good mileage for a clutch,so start saving up for your new clutch!


#11

toyotalover,
JayWB asked you to do a stall test. The engine stalled. This shows that the problem isn’t, actually, a slipping clutch. The fault is that the clutch disc isn’t actually contacting the clutch pressure plate at those times you describe. You do need to remove and replace your…mechanic.


#12

Or maybe you could just keep using premium fuel …


#13

Letting out the clutch to see if it stall isn’t a good enough test, as most engines aren’t making peak torque at low rpm. It only proves is that the clutch doesn’t slip with low torque, but it won’t reveal if the clutch is on its way out until you get stuck on a hill because the clutch can’t handle the max power from the engine. You need to floor it from idle to redline in 3rd gear. If it slips, the engine will suddenly get louder than it should.


#14

No, I don’t agree.

First, one does not check for a slipping clutch in third gear. One uses the highest gear available, because that will be the most likely to produce slippage. On the road, a clutch slipping badly in high gear might not slip at all in lower gears because the torgue multiplication of the transmission in the lower gear allows the limited traction of the clutch disk to move the car. Higher gears eliminate the torque multiplication.

Flooring the throttle to test the clutch will harm the clutch, possibly not ruining it, but certainly damaging it. And it certainly won’t do the engine much good. 2 thousand or 25 hundred RPMs is plenty to show a slipping clutch.


#15

Has there been any change, any change at all, in the way the clutch pedal “feels” when you shift the vehicle or put it in gear?

In their final moments of life, just before they come completely unglued, clutches can act pretty funny. And, Please, FORGET the premium gas thing…

here is what usually happens. Clutch facings are RIVETED to a steel flex-plate. When worn out, the brass rivit heads touch the flywheel and pressure plate and start taking the place of the friction material which has worn away. The rivits provide little friction and the clutch starts to slip. As more friction material gets worn away, it slips worse. Finally, the rivets are worn away, the friction material (think brake linings) is free to fly out of the clutch, and there are some ugly sounds as forward motion ceases…THIS repair bill can bring a smile to any mechanics face, as EVERYTHING inside the bell-housing must be replaced…


#16

I’m well aware that letting out the clutch with the engine at redline amongst to abuse. What I mean was, do a normal start, work your way up to 3rd gear, flooring the gas pedal after the clutch is completely out. If the clutch is bad, engine power can break loose the engaged clutch. My point was that even if the clutch graps ok at idle, it can still break loose when you least want it to, at a freeway onramp or while going uphill.

You can do it in the top gear, but in some cars, that would be reckless driving if you do it on public road.


#17

well, Jay, I think you summed it up correctly.