Self Adjusting vs Non Self Adjusting Clutch

[partsguy84823]

Hey guys, I am looking around at replacing my clutch and I am wondering witch version to buy. At the local O'Reilly they have one SACHS Item #: K70154-02 that they say has a "self adjusting cover". They also have SACHS Item No: K70334-01 and it is "non self adjusting. From my understanding, all hydraulic clutches are self adjusting, so I'm wondering what the difference is between the two. Also, has anyone used these O'Reilly clutches? If so, what do you think? Thanks for the input!

 

[partsguy84823]

Anyone? Anyone at all? I really don't want to have to regret not using the self adjusting clutch, or spending 50 bucks that could have gone towards something else...

 

[jeffro184]

the adjusting one compensates for the clutch wear if you are useing a cable. your truck uses hydraulics so they compensate for wear. factory ford pressure plate is non adjusting

 

[partsguy84823]

Thanks, that was what I was thinking... so good to see someone else agrees.

 

[jeffro184]

no problem, i work as a ford service technician so i think i might know haha and i am the trans guy!

 

[partsguy84823]

hey, I know its been a bit since I have posted to this thread, but where in MI are you located jeffro? I have a bunch of family in Beal City (about 5 miles west of Mt. Pleasent, or about 42 miles east of big Rapids).

 

[AllanD]

It's a ctually more a matter that the angle of the diaphram "fingers" change as the clutch wears.

And while the slave cylinder has enough surplus travel to deal with that the
fingers start out nearly "Flat" early in the disc's wear cycle, and "tent" towards
the transmission and that changes the geometry and increases pedal effort.

The "adjustable" pressure plate is designed to reduce that effect.

The non-adjustable clutch cover is what leads to the classic symptom
of the clutch getting gradually harder to release just before it starts
it's terminal slide (pun intended) towards replacement.

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[partsguy84823]

Thanks Allan for the response. I know you are a big advocate of not using stock clutches unless its a 4.0 clutch... but if you were going to install a stock replacement (not saying I am, just gathering ideas) would you get the "self adjusting" version?

Also while I have your attention, do you know why the clutch would be hard to release after a long (say 100 mile) drive on the highway, but fine at all other times?

Thanks everyone for the help!

 

[Will]

I've never heard of this.

I would go to dialaclutch.com and get the standard LUK for your application. I've had one in my truck since 2001 and it's just like new. Any clutch will last forever as long as you only slip it when you initially start out. After that, never apply the gas unless the clutch pedal is all the way up. That generally entails shifting, counting one-thousand one and then let the pedal up and then accelerate.

When you can get the clutch up without killing the engine, you can drive a stick. The next step is to drive it well. That means not using the clutch to absorb gross differences between the speed of the flywheel and the speed of the input shaft. You waste energy by turning power into heat and you wear out parts that would last forever with a thoughtful person behind the wheel.

I drive my Honda mostly now so I use that as an example. Slip clutch minimal amount to start out, and accelerate to 3,000; clutch in and shift; wait for 1,800; clutch out; accelerate to 3,000; clutch in and shift; wait for 2,000; clutch out; accelerate to 3,000--and so on. I never simultaneously clutch and gas. Even starting out it's mostly clutch at first and as soon as the engine will hold it, it's on its own.

 

[partsguy84823]

Will, thanks for the advice. I've had the truck since 30k miles, and its at 150k now, and I've never replaced the clutch (I assume it wasn't replaced before I got it, lol). It gets lightly wheeled a lot, tows a HUGE (read 4 seater) jet ski, with a bed full of camping gear, almost every weekend of the summer, and the disc still has plenty of meat on it. So I think I can clutch pretty well, I drive it about how you described.

Anyway, I am looking into replacing it because I am getting some goofy hyd. issues, almost like there is a delay in the system. Its weird, but at any rate, I have had fine luck with the stock clutch. So maybe LUK will be where it is at.

 

[Will]

Can you describe the delay?

I bought my '91 from a guy in Kansas City in '01. It had a bad tranny. Turns out the rubber plugs came out and he kept driving until the front cluster (I think) failed. This made the clutch disk hard to slide up and down the waving input shaft and he kept driving it by stomping the pedal really hard and eventually pushed the master cylinder out, tearing a hole in the firewall. At least that was what I concluded.

 

[AllanD]

I'm not currently running the "adjustable" pressure plate.

I have one, but I'm not running it... Yet.

I am however running a combination I wouldn't persnally recommend to others

I'm running the "Early" (83-92) master cylinder with a '93 up Slave cylinder.

This combination gives a VERY firm pedal feel, I'm 6'4" and 300# and in highschool I BROKE the leg press setup in a universal Gym weight machine... so pressing a stiff clutch pedal isn't at all difficult.

What I wanted wasn't the stiff pedal, but the quick action.
See, I like a clutch that's nearly "on or off", I want to push that
pedal no more than 3/4" to release the clutch to upshift.

Also if my slave starts leaking I have gobs of "Reserve pedal"

I can easily modulate that pedal, mostly through sheer strength
but I can do it..

I will say that STIFF swift clutch action matches well with my Hurst shifter.

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[partsguy84823]

The delay is like this... press the clutch pedal... wait... now it releases... Fluid is 100% full and always has been. I replaced the MC last summer and it helped a bit, but its still not how I want it to be.

Allan, I kinda like how that hybrid clutch setup sounds. I would consider giving that a shot when I do this work. The early MC will attach to the late SC without mod. I assume?

 

[AllanD]

Not possible for you to use the combo I'm using.

The "early" master cyl with the bigger bore was designed to
work wih the REALLY EARLY external slaves and the first two types
of internal slaves (the '85-87 and '88-92 aluminum slave cylinders)

The plastic slave used from 1993-current(sfaik) was designed to work
with the smaller bore M/C.

The '93-94 slave is twist-lock mouted to a metal cup that is in turn bolted
to the firewall like the early master cylinder.

the '95-up M/C is also a twist-lock mounted master cylinder
but it's a smaller diameter body for the twist lock and it mounts
directly to the pedal support (NOT the firewall)

So you can't do it.

Someone with a '93-94 could by swapping in an '83-92 M/C
OR someone with an '83-92 could swap in a '93 up slave, but
that's the limit of the physical interchangeability.

The really screwed up setup is the people who dislike the '93-up
"plastic" slave (It's actually a glass fiber reinforced superplastic
called Delrin) and want a "metal" slave and swap the '88-92 slave
and try to run it with the '93-94 slave, which doesn't work well....

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[partsguy84823]

:disappointed face: oh well... thanks for the info anyway.