So I've read many opinions on whether or not to get off the clutch and put the car in neutral when stopped for a while (like at a red light). My friend was saying that that wouldn't really be necessary for newer cars with self-adjusting clutches, since the wear from having the clutch disengaged would be negligible. Does the 350Z have a self-adjusting clutch (search turned up nothing)?

 

I never heard of it

 

If the clutch is fully disengaged there shouldn't ever be any wear until you reengage it. Maybe he means hydraulic clutch, which yes we do have that. My old VW bug had a cable clutch and cables tend to stretch and break after a while so maybe that's what he's talking about.

 

Some cars have self-adjusting clutches. Both my old Mustang Cobra and Daytona Shelby had it. They were both cable clutches, though. The Z's clutch is not self-adjusting. It will probably need some tweaking as the clutch plate wears.

 

Thanks for the input folks. Here is a quick description of what a self-adjusting clutch is. The remainder of my Google search shows a lot of references to BMW, so it seems they might be champions of this technology. Them Bones, I also saw some hits for Ford cars/trucks in that search. Is there a way to tell, say, by feel?

 

I think that your friend was actually referring to the 'throw-out bearing' which operates when the clutch is depressed. If you are idling for a long time and put the car in neutral with the clutch engaged, the throw-out bearing is not being used.

 

All Hydraulic clutches are "self adjusting", as are hydraulic brakes.

 

That's what I hate. Two posters here, sounding like they know wht they're talking about, each with a completely different opinion. One guy say's that the hydraulic clutch is NOT self adusting, the other guy says ALL hydraulic cluthces are. WTF? Them Bones accepts that it's a hydraulic cutch, yet still claims that it's not self adjusting. Then Silver Bullit II implies that since the Z clutch is hydraulic, then by default it must be self adjusting due to it's hydraulic nature. That's the thing about the internet man...you just never know who you're listening to...

 

I'll second that.

 

i will third that.

I know from experience because my 95 integra gsr was a hydro clutch that was self adjusting, I know that because i tried adjusting it once and there was nothing to adjust other than pedal freeplay.

 

A hydraulic clutch "linkage" system is like a simple brake system. It has a master cylinder to provide hydraulic pressure, tubing and a flexible hose to carry the hydraulic fluid, and a slave cylinder which operates the release fork and release bearing.

The hydraulic system has several advantages over its mechanical and cable counterparts. The tubing can be easily routed wherever it needs to go. The pedal pressure is less due to the lack of friction that is inherent in any cable or mechanical system. And finally, the clutch pedal action is extremely smooth. The only down side to the hydraulic system is cost, which is why some vehicles made today still use a cable.



As you can see in Figure 1, the master cylinder is a simple single piston device. The reservoir supplies hydraulic fluid (usually brake fluid) to the cylinder inlet port. The reservoir may be mounted to the cylinder (as in the illustration) or mounted remotely and connected to the cylinder by a hose. The cylinder is bolted to the firewall and has a pushrod that that attaches to the clutch pedal. A hole in the cylinder body (inlet port) supplies fluid to the cylinder bore. The push rod moves the piston into the cylinder bore. As the piston primary cup passes the inlet port, it closes off the passage to the reservoir and pushes fluid out of the cylinder and into the tubing connecting the master cylinder to the slave cylinder. The secondary cup prevents any fluid from leaking out of the back of the master cylinder and into the passenger compartment.

The primary force returning the clutch pedal to its full upper position is the clutch pressure plate spring working against the slave cylinder piston, the fluid, and ultimately the master cylinder piston. The return spring inside the master cylinder helps push the piston back against the stopper ring to ensure that the inlet port is uncovered when the clutch pedal is released. The stopper ring prevents the piston from falling out of the back of the master cylinder.

As shown if Figure 2, the slave cylinder is also a single piston cylinder. As fluid enters the cylinder, it pushes the piston outward and causes the push rod to move the clutch release fork, ultimately moving the release (throw-out) bearing to disengage the clutch. As a typical push-style clutch disc wears thin, the release fingers of the pressure plate move toward the release bearing, reducing free play. This is why mechanical linkages require periodic adjustment.



As the clutch of a slave cylinder-equipped vehicle wears, the release fork pushes the slave cylinder piston further into the cylinder bore. While a few slave cylinder push rods are adjustable, most are not. Simply by making the cylinder longer than the normal pedal stroke required to release the clutch, the hydraulic clutch system is inherently self-adjusting. When the clutch is new, the piston is operating near the open end of the cylinder. As the clutch wears, the piston is pushed deeper into the cylinder, effectively "adjusting" the clutch to compensate for wear.

http://www.babcox.com/editorial/bf/bf70238.htm

 

"ALL" is a pretty big word! Most Hydraulic clutches are self adjusting, as is the Z. There are hydraulic clutches that require a mechanical link to be adjusted, just as there are hydraulic brakes (drums) that have a mechanical adjustment that must be tweeked from time to time.

 

Most hydraulic systems that use a slave cylindar are self-adjusting, like ours.

 

I must say, I feel better about things after reading WashUJon's evidence-backed posts. I like proof.

 

Me, too.

 

Yes.. the "Z" has a hydraulic clutch and it needs NO adjustments.. I went 178,000 miles on my 1974 260Z all on the factory clutch..
Unless you ride the clutch or just plain abuse it, it should last a long time.

Steve (k2we) Dobbs Ferry, NY 13,333 miles since Sept 17,2002

Car is 1 year old today!!

 

Thanks for all the info folks, especially WashU for the great lesson!

 

No prob. I'm happy to have helped some. I knew about the clutch, but it just took me a quick minute to find that article and verify my knowledge.

 

good info to know i never knew about any of this, but at stop lights i always put it in neutral so it never really applied to me but now i know fo sho. pretty interesting stuff...

 

So does that mean when the car is new you don't have to push the pedal down as far and as the car gets older you do have to push the pedal down farther?

I was pretty suprised by how much play there is in the Z's clutch (how far the pedal goes from fully out to fully in). I would have though a much shorter range would be better for quick shifting.