Porsche 911 Carrera Technical Manual page 182

911 Carrera (996) Final drive -Differential, differential lock
39 08 15
Adjusting drive set -GT3
7. Secure the universal dial gauge holder VW
387 with dial gauge and extension on the
housing and set it to "0" with 2 mm preload.
Adjusting crown wheel
Determine the total disc thickness "$ tot."
($1 + $2).
Readjustment of the crown wheel is necessary if:
the transmission housing, side transmission
cover, taper roller bearings for the differential,
differential housing or gear set is replaced.
Note
The pinion shaft must be removed in order to
determine the preload of the tapered roller
bearings on the differential.
1. Make sure that the bearing outer races of the
tapered roller bearings are firmly seated in the
transmission housing or in the side trans-
mission cover.
365_99
A = Dial gauge extension
(approx. 30...40 mm long)
B = Final dimension plate VW 385/17
2. Fit one 2.5 mm thick spacer ring each on the
crown wheel side and the opposite side of the
differential to be used.
8. Move the differential up and down with special
tool VW 521/4. Read and make a note of the
play indicated on the dial gauge.
3. Fit special tool VW 521/4 opposite the
crown wheel (S2 side) in the differential
housing.
Note
Do not turn the differential when measuring the
play, otherwise the measurement result will be
falsified.
4. Fit differential into the transmission housing
and turn it through several revolutions.
5. Install the side transmission cover without
sealing ring and tighten all hexagon-head bolts
to 25 Nm (19 ftlb.).
9. Calculate "S tot.".
"S tot," = Shim thickness used
+ Measurement result
+ Compression of the tapered
roller bearings
6. Place the final dimension plate VW 385/17
onto the collar of the differential.
39 -227
39 08 15 Adjusting drive set -GT3
Printed in Germany -29, 1999
GT339227