Daniel:

What are your thoughts on car ramps? I bought a set of these new plastic Rhino Ramps in preparation for my oil pressure sensor change. The ramps only have a 17 degree incline so as not to damage bumpers. From what I read on other boards, they are quite popular especially with the Mazda Miata owners. I thought they were would be more stable than traditional metal ramps on account of their wedge design yielding a larger footprint for contact on the garage floor. With my 5 spd. it was a little nervewracking getting the car up the ramps since I was moving extremely slow trying to be very careful not to fully release the clutch thereby launching the car up and over the ramps and at the same time trying not to take too long to get up them since I figure the clutch was slipping more than usual. Have you ever used ramps with a MT and do you think this occasional amount of clutch slippage is acceptable?

Thanks

 

I'm not Daniel, however:

The ramps are fine. I'm not sure of they are any more stable than the metal ramps, but they work just as well.

Your clutch is not actually slipping. It is remaining engaged. You are just riding it a bit in order to avoid stalling or launching yourself over the ramp. This is fine
-- as long as you don't sit there for hours getting yourself up onto the ramp. Just be sure to use your parking brake once you are up on the ramp. Also, use chocks on the back tires when on the ramp. You can never be too cautious.

 

Don't worry about the clutch. After a while you will "get the hang of it" and be able to drive up onto the ramps with very little clutch slippage.

Ramps are inexpensive and convenient. I prefer a floor jack and sturdy jackstands. These are less convenient than ramps but are more versatile. For example, ramps are fine for oil changes but not good for brake pad replacement or tire rotation.

 

Thanks Daniel and Ajaffee.

Daniel, I am right though that while moving slowly in first gear up the ramps that a certain amount of slippage is occuring, right? I was later concerned that since at one point I paused midway up the ramps with the clutch partially out and rpms revved a little, this could cause heating and glazing but as Ajaffee points out, one would hope this would be under extended periods of slippage time on the ramp's incline. After thinking about it, certainly people living in hilly areas subject this to their cars daily when they must engage 1st gear on a hill like in San Francisco.

Also, another question comes to mind. Does the clutch plate friction material become abraded and lose material similar to brake pads over time?

 

Yes. When the clutch pedal is all the way down or all the way up there is no slippage. Anywhere in between the two extremes, there is slippage.

Yes.

Clutch life depends on driving environment and driving style. A clutch will wear quickly in a stop-and-go urban environment. A clutch will last more than 200K miles if used in highway driving. The driver who engages in stoplight races will wear out his clutch quickly.

Clutch replacement is not inevitable. I have owned several stick-shift cars and have never worn out a clutch, even on cars driven more than 150K miles.

 

Daniel:

I take it then that occasional higher that usual revs with clutch partially out (such as driving up ramps) or starting from a stop on hills will not burn or glaze a clutch. I understand that this can happen however and was curious what conditions would cause that. Once glazed, is the damage irreversible or will the glaze wear off with use? What are the indications of a failing clutch?

 

Occasional ramp-climbing will do no harm.

An experienced driver can start from rest on a steep hill with very little clutch slippage. If you find it helpful, you can apply the handbrake until it is time to get moving. In one synchronized motion you feed gas, engage the clutch, and release the handbrake.

Abusive driving practices such as ...
- stoplight racing
- towing a trailer heavier than the factory-recommended maximum
- "holding" a grade by slipping the clutch rather than using the foot brake or handbrake (ugh!)

I've encountered some misinformed drivers who think they are "saving the brakes" by downshifting 5th-to-4th-to-3rd-to-2nd as they approach a red traffic light. They fail to realize they are saving the brakes at the expense of increased wear on their clutch and transmission synchronizers. Brake pads are cheap, clutches are not.

I've never known it to wear off.

A good test for a slipping clutch is to travel on a level road at 50 mph in 5th gear. Floor the gas pedal. If the engine rpm increases quickly but the vehicle speed does not, you have a slipping clutch. The sensation is similar to spinning your wheels on an icy roadway.

 

I've encountered some misinformed drivers who think they are "saving the brakes" by downshifting 5th-to-4th-to-3rd-to-2nd as they approach a red traffic light. They fail to realize they are saving the brakes at the expense of increased wear on their clutch and transmission synchronizers. Brake pads are cheap, clutches are not.

i agree with you here daniel, but if you rev-match (properly) while downshifting, it shouldn't wear the clutch much or the synchros at all, right?

rob

 

sorry, didn't quote that lost post right. that first line is meant to be quoted from daniel's post.

rob

 

I'll agree, if you change the word properly to perfectly. Few of us are that good.

For that matter, the driver who can rev-match perfectly doesn't even need to step on the clutch to shift gears.