Throwout Bearing Clearance

Ref: RCR40, 363 SBF, ZF Trans, Safir SBF Clutch Kit (dual disc McLeod w/adjustable T/O Bearing). I'm wondering how much no-load clearance there should be between the throwout bearing and the clutch pressure plate actuating arms? With everything installed on the engine, I have almost no feeling of any movement when I try to rotate the operating arm. I'm wondering if I should remove one of the T/O Brng Shims and then adjust the operating arm as needed?

While there are release bearings that ride the fingers of the pressure plate always - I prefer to have some minute clearance. That clearance will generally be reduced as the clutch disk wears.

You need to have roughly .200" clearance between the PP and bearing face. That measurement will decrease as the clutch wears.

Ron & Randy, thanks for the replies.

Ron, am I reading .200 correctly? In fractions, that's somewhere between 3/16 & 1/4". I'm certainly not disputing this because I figure you know more about this stuff than I do, but it seems like a lot.

It does to me too. Just adjust the clearance so that there is no contact between the clutch disk and the pressure plate, then add a little bit more clearance to allow for thermal expansion, etc. Constant contact ("drag") will wear out your clutch disk pronto.

If this is a hydraulic release, if so it will find it's own adjustment ( fingers to bearing ). I set the travel in my clutch pedal travel to get proper disengagement and not bottoming out the slave.

RdstrRod said:

Ron & Randy, thanks for the replies.

Ron, am I reading .200 correctly? In fractions, that's somewhere between 3/16 & 1/4". I'm certainly not disputing this because I figure you know more about this stuff than I do, but it seems like a lot.

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Rod,
The actual freeplay will be adjusted from the outside by lengthening or shortening the actuation rod (between the slave cylinder and clutch lever)
after the trans is installed.
The clearance that I mentioned is needed initially so that you can maintain the desired freeplay throughout the life of the clutch.
If this clearance is not there initially, as the clutch wears , the fingers will migrate towards the bearing ( watch them move as you tighten the bolts during installation of the pressure plate) and the clutch will become partially disengaged and slip.
Hope this explains it a bit more clearly.

Ron

Ron,
Thanks for the clarification. It all makes sense now. Simply obtain the initial clearance, then adjust using the actuation rod. If anyone needs me, I'll be out in the garage today pulling the ZF back off.

Rod

Most important is indexing the bell housing to block !!!!

Randy said:

Most important is indexing the bell housing to block !!!!

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Probably not Most important, but more likely equally so. Anyway, yes, that has been done already. Interestingly, I had never heard of indexing a bell housing until the wisdom of you guys on this forum came forth. Many thanks again to all for trying to keep me on the right path.

Rod