Porsche 928 Workshop Manual page 672

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a
928
Clutch/Controls
30
Intermediate Ring
Beginning with 1984 models there is a separate test connection, which is connected with a
TDC sensor, for checking the ignition timing. The TDC sensor signal is triggered by two
cylindrical pins which are pressed in the gear ring of the clutch intermediate ring. This makes
precise positioning between the intermediate ring and flywheel necessary.
This position is guaranteed, in that one of the three centering pins in the intermediate ring
has two different diameters on each end, namely 6 mm and 8 mm. A centering bore in the
flywheel now has a 8 mm diameter. Consequently the intermediate ring can only be mounted
in one position.
Central Shaft I
The first version of central shaft 928.421.235.12 (no longer available) was sometimes
installed together with new clutch parts.
The modified central shaft 928.421.235.13 was replaced with central shaft 928.421.235.16
(hard nicle-plated/same size) as from June of 1983. Central shaft 928.421.235.13 will no
longer be available after depletion of stocks.
Axial movement of clutch discs on central shaft I is better after long operating time when
using the hard nickle-plated version in conjunction with the specified lubricant.
Identification: 928.421.235.13 gray/black
928.421.235.16 dull silver
Lubricant specifications for splines (central shaft I and clutch discs):
928.423.235.12 and
928.423.235.13
very thin coat of Optimoly HT
928.423.235.16
coat of Optimoly Olista Longtime 3 EP
(Part No. 000.043.024.00)
Release Bearing Sleeve
When repairing clutch, the old release bearing sleeve 928.116.087.11 with a total length of
50 mm can be ground off to a length of 49 mm.
Printed in Germany - VIII, 1984 Disassembling and Assembling Clutch 30.16a
(Dowel Pin Centered)