The short answer, yes and no.
Long answer - it depends on the type of release bearing and MC type.
As the clutch plate wears, the pressure plate fingers/release levers
will move outwards and take up any release bearing clearance. IOW, there
always needs to be *some form of adjustment. The difference is whether
said adjustment is automatic or manual.
English cars often used a carbon thrust block release bearing. These
were designed to maintain contact with a thrust plate attached to the
pressure plate fingers. They are made of a graphite base compound and
are self lubricating. The reason these were used is that the thrust
block does not remain concentric with the thrust plate on the clutch
during clutch operation and this would rapidly wear a ball thrust
bearing. In the past, centre valve master cylinders were used with this
configuration as these provide free fluid flow between master and slave
cylinder in the engaged position, no residual pressure retained. This is
an important point. The carbon thrust block type release bearing
normally runs a light engagement when the clutch is engaged and the foot
is off the clutch pedal. The engagement pressure is the *weight* of the
fluid in the clutch hydraulics. The clue to this is the lack of a return
spring on the outboard end of the clutch fork. It is not required and
the system automatically compensates for plate wear.
Cars using ball thrust release bearings generally require a *clearance*
between the bearing and the clutch fingers when the clutch is engaged
and the foot is off the clutch pedal. It is not advisable to have the
ball thrust bearing rotating continuously. In contrast to the carbon
thrust block, in the ball thrust release bearing there exists an
arrangement, a release bearing guide structure, whereby the release
bearing is maintained in concentricity with the pressure plate, even
when the clutch is fully disengaged and the pedal fully depressed. The
ball thrust release bearings are characterised by a return spring on the
clutch fork and an adjustment at the slave cylinder pushrod.
Regardless of the presence or absence of an adjustment to compensate for
wear of the clutch plate, all hydraulic clutches generally have a
clearance adjustment *at the pedal pushrod*. This is to ensure the full
return of the master cylinder piston to its stop or, in some cases, to
allow proper MC piston positioning. In the case of compensation port
master cylinders, failure to fully return the piston to its stop will
cause the hydraulic system to retain pressure in the hydraulic lines and
cause a dragging release bearing and premature wear. It is for this
reason that clutch master cylinders do not have residual line pressure
valves in their outlet port.
Nothing astonishes Noddy so much as common sense and plain dealing.
I got a surprise today when leaving for work, I wasn't getting enough torque to drive up the hill. After warming up for a half a minute it got better. 1994 Saturn SL 2 has a lot of little flaws, but is generally very reliable.
Well I sure was wrong. Today warming up didn't help and the electrical faul
ts got massively worse, clock radio flickering, nasty tap noise on the radi
o, lights went out, and when I drifted it down the hill and parked it the c
licking noise continued AFTER I took the key out.
I'm guessing the whole thing is a failed battery. I bought a new one almost
3 years ago. Now, the big surprise is that the clutch is talking to the el
ectronics, which doesn't seem necessary to me. I know from an older problem
that some mysterious "rss sender" gives a lot of components ideas of what
94 Saturn SL2, anybody know what electronics talk to the clutch/transmissi
Nils K. Hammer
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.