<VV> Clutch Head Fasteners & Drivers

Tue May 26 20:13:16 EDT 2009

aka, turn clutch, "butterfly," figure-8, or clutch type "G"

there are, apparently, some called clutch head that look more like a 
propeller blade, and they are not type G  [they do exist, at least I 
have bits for them ...]

Having just spent an hour online, looking for these things, all I can 
say is I am glad I've got mine!  Apparently Xcelite and Apex no longer 
manufacture clutch head drivers, and that is where many of mine came 
from -- they are also used on some Corvair horn switch rings, and in the 
metering blocks of at least some older Holley carbs, so it's not just a 
GM thing.

Snap-On used to offer six regular clutch head screwdrivers from 1/8" to 
3/8", SSDC-4 to SSDC-12.  I have a Snap-On  3/8" drive socket tool for a 
larger size of clutch heads (bigger than engine lid screws) marked "F 
29". This old Snap-On catalog I have says the "F-29A Driver, Bit Diam 
3/8", fits 3/8" and 13/32" screws" -- seems to match my driver. It also 
lists an "F-30 Driver, bit diam 19/64" .

The driver socket that I have that fits the engine lid screws is an Apex 
2827-G, and it is 0.295" across the large diameter of the tip -- that is 
about 19/64".

Currently (at this moment) the online Snap-Off catalog lists:

Socket Driver, Clutch, Standard, 5/16", Stock#: F30E

Stock # 	F30E
Name 	Socket Driver, Clutch, Standard, 5/16"
<http://buy1.snapon.com/catalog/item.asp?search=true&item_ID=73783&PartNo=F30&group_id=280&supersede=&store=snapon-store&tool=all#Li>Price
	$14.00    
Description 	19/64" Clutch Socket Driver
Size 	5/16"
Finish 	Chrome
Type 	Clutch-Type
Dimension A, Bit Dia., inches 	19/64
Dimension B, Length, inches 	1 3/4

So maybe, from the websites listed below, a nominal 5/16" driver might 
fit the engine cover screws:

http://shoptoolsshoptools.com/shopdisplayproducts.asp?id=512&cat=Clutch+Head+Screwdrivers
http://www.lategreatchevy.com/product.asp?pf_id=563969&dept_id=1095
http://www.mikeschevy.com/servlet/the-3005/55-56-57-CHEVY/Detail

Or, the Snap-On tool appears to be available, and there is always 
e(vil)Bay ...

Bill Strickland