Porsche training p30g drivetrain repair sports car

®

AfterSales Training
Drivetrain Repair – Sports Cars
911 (996)/Boxster “S” (986) 6-Speed Manual Transmission

P30G


Porsche AfterSales Training
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Important Notice:The contents of this AfterSales Training brochure was originally written by Porsche AG for its rest-of-world
English speaking market. The electronic text and graphic files were then imported by Porsche Cars N.A, Inc. and edited for content. Some equipment and technical data listed in this publication may not be applicable for our market. Specifications are subject to change without notice.
We have attempted to render the text within this publication to American English as best as we could. We reserve the right to
make changes without notice.
© 2007 Porsche Cars North America, Inc. All Rights Reserved. Reproduction or translation in whole or in part is not permitted
without written authorization from publisher. AfterSales Training Publications
Dr. Ing. h.c. F. Porsche AG is the owner of numerous trademarks, both registered and unregistered, including without limitation
the Porsche Crest®, Porsche®, Boxster®, Carrera®, Cayenne®, CaymanTM, Tiptronic®, VarioCam®, PCM®, 911®, 4S®, and
the model numbers and distinctive shapes of Porsche’s automobiles such as, the federally registered 911 automobile. The third
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specifications to be correct at the time of printing. However, specifications, standard equipment and options are subject to
change without notice.
Part Number - PNA P30 G01

Edition - 4/07

Table of Contents

Description

Section

Transmission Type Designations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Six-Speed Transmissions – G96.00/01/30/31, G86.20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Final Drive Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Conversion Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Drivetrain Repair – Sports Cars 6-Speed


Drivetrain Repair – Sports Cars 6-Speed


Transmission Type Designations
Transmission Number Identification
Digit:

1

2 3 4 5

6 7 8 9 10 11

Example:

G

5 0 2 0

1 0 0 5 4 3

Transmission Type:
Transmission Version:
Index of Variants:
Serial Number:

911, Boxster and Cayman Transmission Type Designations Since Model Year 1989
Model
Year

Transmission
Type

Technical
Data

Installed In

1989

G50.00
G50.01
G50.02
G50.50
G64.00

G64.01

5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T

911 Carrera - RoW
911 Carrera - USA, Australia, Japan
911 Carrera - Switzerland
911 Turbo - World-Wide
911 Carrera (964) - RoW, USA/Canada
911 Carrera 4 (964) - Switzerland

1990

A50.01
G50.03
G50.04
G64.00
G64.01

4-Speed A/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T

911 Carrera 2 (964) - RoW, USA/Canada
911 Carrera 2 (964) - RoW, USA/Canada
911 Carrera 2 (964) - Switzerland
911 Carrera 4 (964) - RoW, USA/Canada
911 Carrera 4 (964) - Switzerland

1991

A50.01
G50.03
G50.04
G50.52
G64.00
G64.01

4-Speed A/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T

911 Carrera 2 (964) - RoW, USA/Canada
911 Carrera 2 (964) - RoW, USA/Canada
911 Carrera 2 (964) - Switzerland
911 Turbo (964) - World-Wide
911 Carrera 4 (964) - RoW, USA/Canada
911 Carrera 4 (964) - Switzerland

1992

A50.02
A50.03
G50.03
G50.04
G50.05
G50.10
G50.52
G64.00
G64.01
G64.02

4-Speed A/T
4-Speed A/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T

911 Carrera 2 (964) - RoW
911 Carrera 2 (964) - USA/Canada
911 Carrera 2 (964) - RoW
911 Carrera 2 (964) - Switzerland
911 Carrera 2 (964) - USA/Canada
911 Carrera 2 RS (964) - RoW
911 Turbo (964) - World-Wide

911 Carrera 4 (964) - RoW, USA/Canada
911 Carrera 4 (964) - Switzerland
911 Carrera 4 (964) - Taiwan

Drivetrain Repair – Sports Cars 6-Speed

Page 1.1


Transmission Type Designations
Model
Year

Transmission
Type

Technical
Data

1993

A50.02
A50.03
G50.03
G50.04
G50.05
G50.10
G64.00
G64.01
G64.02

4-Speed A/T
4-Speed A/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T

911 Carrera 2 (964) - RoW
911 Carrera 2 (964) - USA/Canada, Taiwan
911 Carrera 2 (964) - RoW
911 Carrera 2 (964) - Switzerland/Taiwan
911 Carrera 2 (964) - USA/Canada
911 Carrera 2 RS (964) - RoW
911 Carrera 4 (964) - RoW, USA
911 Carrera 4 (964) - Switzerland
911 Carrera 4 (964) - Taiwan

1994

A50.02
A50.03
G50.03
G50.04
G50.05
G50.10
G50.52

G64.00
G64.01
G64.02

4-Speed A/T
4-Speed A/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T
5-Speed M/T

911 Carrera 2 (964) - RoW
911 Carrera 2 (964) - USA/Canada, Taiwan
911 Carrera 2 (964) - RoW
911 Carrera 2 (964) - Switzerland/Taiwan
911 Carrera 2 (964) - USA/Canada
911 Carrera 2 RS (964) - RoW
911 Turbo 3.6 (964) - World-Wide
911 Carrera 4 (964) - RoW, USA
911 Carrera 4 (964) - Switzerland
911 Carrera 4 (964) - Taiwan

1995

A50.04
A50.05

G50.20
G50.21

4-Speed A/T
4-Speed A/T
6-Speed M/T
6-Speed M/T

911 Carrera 2 (993) - RoW
911 Carrera 2 (993) - USA/Canada, Taiwan
911 Carrera (993) - USA/Canada
911 Carrera (993) - RoW

1996

A50.04
A50.05
G50.20
G50.21
G64.20
G64.21
G64.51

4-Speed A/T
4-Speed A/T
6-Speed M/T
6-Speed M/T
6-Speed M/T
6-Speed M/T
6-Speed M/T

911 Carrera 2 (993) - RoW
911 Carrera 2 (993) - USA/Canada, Taiwan
911 Carrera 2 (993) - USA/Canada
911 Carrera 2 (993) - RoW
911 Carrera 4 (993) - USA/Canada
911 Carrera 4 (993) - RoW
911 Turbo (993) - World-Wide

1997

A50.04
A50.05
G50.20
G64.20
G64.51
A86.00
G86.00

4-Speed A/T
4-Speed A/T
6-Speed M/T
6-Speed M/T
6-Speed M/T
5-Speed A/T
5-Speed M/T

911 Carrera 2 (993) - RoW
911 Carrera 2 (993) - USA/Canada, Taiwan
911 Carrera 2 (993) - RoW, USA/Canada

911 Carrera 4 (993) - RoW, USA/Canada
911 Turbo (993) - World-Wide
Boxster (986)
Boxster (986)

1998

A50.04
A50.05
G50.20
G64.20
G64.42
G64.51
A86.00
G86.00

4-Speed A/T
4-Speed A/T
6-Speed M/T
6-Speed M/T
6-Speed M/T
6-Speed M/T
5-Speed A/T
5-Speed M/T

911 Carrera 2 (993) - RoW
911 Carrera 2 (993) - USA/Canada, Taiwan
911 Carrera 2 (993) - RoW, USA/Canada
911 Carrera 4/4S (993) - RoW, USA/Canada
911 Turbo (993) - Taiwan

911 Turbo (993) - RoW, USA/Canada
Boxster (986)
Boxster (986)

Page 1.2

Installed In

Drivetrain Repair – Sports Cars 6-Speed


Transmission Type Designations
Model
Year

Transmission
Type

Technical
Data

Installed In

1999

A86.00
G86.00
A96.00
A96.30
G96.00

G96.30

5-Speed A/T
5-Speed M/T
5-Speed A/T
5-Speed A/T
6-Speed M/T
6-Speed M/T

Boxster (986)
Boxster (986)
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada

2000

A86.05
A86.20
G86.01
G86.20
A96.00
A96.30
G96.00
G96.30
G96.90

5-Speed A/T
5-Speed A/T

5-Speed M/T
6-Speed M/T
5-Speed A/T
5-Speed A/T
6-Speed M/T
6-Speed M/T
6-Speed M/T

Boxster (986)
Boxster S (986)
Boxster (986)
Boxster S (986)
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada
911 GT3 (996) - RoW

2001

A86.05
A86.20
G86.01
G86.20
A96.00
A96.30
G96.00
G96.30
G96.50
A96.50

G96.88
G96.90

5-Speed A/T
5-Speed A/T
5-Speed M/T
6-Speed M/T
5-Speed A/T
5-Speed A/T
6-Speed M/T
6-Speed M/T
6-Speed M/T
5-Speed A/T
6-Speed M/T
6-Speed M/T

Boxster (986)
Boxster S (986)
Boxster (986)
Boxster S (986)
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada
911 Turbo (996) - World-Wide
911 Turbo (996) - World-Wide
911 GT2 (996) - World-Wide
911 GT3 (996) - RoW

2002

A86.05
A86.20
G86.01
G86.20
A96.10
A96.35
G96.01
G96.31
G96.50
A96.50
G96.88

5-Speed A/T
5-Speed A/T
5-Speed M/T
6-Speed M/T
5-Speed A/T
5-Speed A/T
6-Speed M/T
6-Speed M/T
6-Speed M/T
5-Speed A/T
6-Speed M/T

Boxster (986)
Boxster S (986)
Boxster (986)
Boxster S (986)
911 Carrera 2 (996) - RoW, USA/Canada

911 Carrera 4 (996) - RoW, USA/Canada
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada
911 Turbo (996) - World-Wide
911 Turbo (996) - World-Wide
911 GT2 (996) - World-Wide

Drivetrain Repair – Sports Cars 6-Speed

Page 1.3


Transmission Type Designations
Model
Year

Transmission
Type

Technical
Data

2003

A86.05
A86.20
G86.01
G86.20
A96.10
A96.35

G96.01
G96.31
G96.50
A96.50
G96.88

5-Speed A/T
5-Speed A/T
5-Speed M/T
6-Speed M/T
5-Speed A/T
5-Speed A/T
6-Speed M/T
6-Speed M/T
6-Speed M/T
5-Speed A/T
6-Speed M/T

Boxster (986)
Boxster S (986)
Boxster (986)
Boxster S (986)
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada
911 Turbo (996) - World-Wide
911 Turbo (996) - World-Wide
911 GT2 (996) - World-Wide

2004

A86.05
A86.20
G86.01
G86.20
A96.10
A96.35
G96.01
G96.31
G96.50
A96.50
G96.88
G96.96

5-Speed A/T
5-Speed A/T
5-Speed M/T
6-Speed M/T
5-Speed A/T
5-Speed A/T
6-Speed M/T
6-Speed M/T
6-Speed M/T
5-Speed A/T
6-Speed M/T
6-Speed M/T

Boxster (986)
Boxster S (986)

Boxster (986)
Boxster S (986)
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada
911 Turbo (996) - World-Wide
911 Turbo (996) - World-Wide
911 GT2 (996) - World-Wide
911 GT3 (996) - USA/Canada

2005

A87.01
A87.20
G87.01
G87.20
A96.10
A96.35
G96.01
G96.31
A97.01
G97.01
G96.50
A96.50
G96.88
G96.96

5-Speed A/T
5-Speed A/T

5-Speed M/T
6-Speed M/T
5-Speed A/T
5-Speed A/T
6-Speed M/T
6-Speed M/T
5-Speed A/T
6-Speed M/T
6-Speed M/T
5-Speed A/T
6-Speed M/T
6-Speed M/T

Boxster (987)
Boxster S (987)
Boxster (987)
Boxster S (987)
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada
911 Carrera 2 (996) - RoW, USA/Canada
911 Carrera 4 (996) - RoW, USA/Canada
911 Carrera/S (997) - RoW, USA/Canada
911 Carrera/S (997) - RoW, USA/Canada
911 Turbo (996) - World-Wide
911 Turbo (996) - World-Wide
911 GT2 (996) - World-Wide
911 GT3 (996) - USA/Canada

2006

A87.01
A87.20
G87.01
G87.20
A87.21
G87.21
A97.01
G97.01
A97.31
G97.31

5-Speed A/T
5-Speed A/T
5-Speed M/T
6-Speed M/T
5-Speed A/T
6-Speed M/T
5-Speed A/T
6-Speed M/T
5-Speed A/T
6-Speed M/T

Boxster (987)
Boxster S (987)
Boxster (987)
Boxster S (987)
Cayman S (987)
Cayman S (987)
911 Carrera 2/S (997) - RoW, USA/Canada
911 Carrera 2/S (997) - RoW, USA/Canada

911 Carrera 4/S (997) - RoW, USA/Canada
911 Carrera 4/S (997) - RoW, USA/Canada

Page 1.4

Installed In

Drivetrain Repair – Sports Cars 6-Speed


Transmission Type Designations
Model
Year

Transmission
Type

Technical
Data

Installed In

2007

A87.02
A87.21
G87.01
G87.21
A87.02
A87.21

G87.01
G87.21
A97.01
G97.01
A97.31
G97.31
G97.50
A97.50
G97.90

5-Speed A/T
5-Speed A/T
5-Speed M/T
6-Speed M/T
5-Speed A/T
5-Speed A/T
6-Speed M/T
6-Speed M/T
5-Speed A/T
6-Speed M/T
5-Speed A/T
6-Speed M/T
6-Speed M/T
5-Speed A/T
6-Speed M/T

Boxster (987)
Boxster S (987)
Boxster (987)
Boxster S (987)

Cayman (987)
Cayman S (987)
Cayman (987)
Cayman S (987)
911 Carrera 2/S (997) - RoW, USA/Canada
911 Carrera 2/S (997) - RoW, USA/Canada
911 Carrera 4/S (997) - RoW, USA/Canada
911 Carrera 4/S (997) - RoW, USA/Canada
911 Turbo (997) - World-Wide
911 Turbo (997) - World-Wide
911 GT3 (997) - USA/Canada

2008

A87.02
A87.21
G87.01
G87.21
A87.02
A87.21
G87.01
G87.21
A97.01
G97.01
A97.31
G97.31
G97.50
A97.50
G97.88
G97.90

5-Speed A/T
5-Speed A/T
5-Speed M/T
6-Speed M/T
5-Speed A/T
5-Speed A/T
6-Speed M/T
6-Speed M/T
5-Speed A/T
6-Speed M/T
5-Speed A/T
6-Speed M/T
6-Speed M/T
5-Speed A/T
6-Speed M/T
6-Speed M/T

Boxster (987)
Boxster S (987)
Boxster (987)
Boxster S (987)
Cayman (987)
Cayman S (987)
Cayman (987)
Cayman S (987)
911 Carrera 2/S (997) - RoW, USA/Canada
911 Carrera 2/S (997) - RoW, USA/Canada
911 Carrera 4/S (997) - RoW, USA/Canada
911 Carrera 4/S (997) - RoW, USA/Canada

911 Turbo (997) - World-Wide
911 Turbo (997) - World-Wide
911 GT2 (997) - World-Wide
911 GT3 (997) - USA/Canada

Drivetrain Repair – Sports Cars 6-Speed

Page 1.5


Transmission Type Designations

Page 1.6

Drivetrain Repair – Sports Cars 6-Speed


911 (996)/Boxster S (986) Transmission

Subject

Page

General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
G96.00 - 911 Carrera 2 (996) Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
G96.01 - 911 Carrera 2 (996)/G86.20 - Boxster S (986) Transmission . . . . . . . . . . . . . . . . . . . .4
G96.30 - 911 Carrera 4 (996) Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
G96.31 - 911 Carrera 4 (996) Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Transmission Cutouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Transmission Ratios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Gears . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Final Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Limited-slip Differential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Shifter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Internal Shifting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Transmission Housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Viscous Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Front Differential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Drivetrain Repair – Sports Cars 6-Speed

Page 2.1


911 (996)/Boxster S (986) Transmission
Notes:

Page 2.2

Drivetrain Repair – Sports Cars 6-Speed


911 (996)/Boxster S (986) Transmission
Transmissions

Transmission – G96.00 - 911 Carrera 2 (996)

General
The 911 Carrera 2/4 (996) and Boxster S (986) (M.Y.

2000-04) came equipped with a 6-speed Manual Transmission or optional Tiptronic automatic transmission.
A completely new transmission was developed for use in
the 911 Carrera (996) and subsequently the Boxster S
(986). The most important development objectives were:
●
●
●
●

One transmission variant worldwide
Adaptation to the engine power
Smooth shifting
Reduction of transmission noise by means of ground
gearwheels and cable shifting

Manual Transmission Types:

The 6th gear has been configured to allow the maximum
possible vehicle speed to be reached. The relatively short
1st gear relieves the load placed on the clutch when the
vehicle moves off and also ensures a favorable crawling
speed. The reverse gear has been considerably
shortened.

911 Carrera 2 (996)
●
●

G96.00 – M.Y. 1999 - 2001
G96.01 – M.Y. 2002 - 05

911 Carrera 4/4S (996)
●
●

G96.30 – M.Y, 1999 - 2001
G96.31 – M.Y, 2002 - 05

Boxster S (986)
●

G86.20 – 2000 - 04

This section describes the manual transmission for the
911 Carrera/4 (996). The 6-speed transmission for the
Boxster S (986) M.Y. 2000-04 is identical except for the
installation position of the ring gear.

Drivetrain Repair – Sports Cars 6-Speed

Page 2.3


911 (996)/Boxster S (986) Transmission
Transmission – G96.01 - 911 Carrera 2 (996) &
G86.20 - Boxster S (986)

Transmission – G96.30 - 911 Carrera 4 (996)

Additional 3rd Bearing on Input Shaft, See Arrow

911 Carrera 4 (996) Driveline Configuration

The manual transmission for the rear wheel drive vehicle
and the four-wheel drive vehicle is based on the previous
911 (993) generation transmission. The manual transmission has been adapted to the higher engine torque of the
911 3.6 l engine with the dimensions and transmission
ratios remaining unchanged. The necessary higher
dynamic strength of the components has been achieved
through the use of higher alloy steels and precision shot
blasting at the pinion shafts. The aluminum die-cast housing has been further optimized with regard to acoustics
and vibration and has been adapted to the new installation
position due to the standardization of the transmission
mounts (manual and Tiptronic).

Power is transmitted to the front axle from the transmission via a single-piece drive shaft and a central shaft to the
viscous multi-disc clutch integrated in the front-axle final
drive.
The advantages of this concept-drive shaft plus central
shaft are the reduced weight and the increased ease of
repair. For example, after the drive shaft has been
removed, it is then possible to remove the transmission
without the engine.

The efficiency has been improved by reducing the drag
factor through decreased preloading on the tapered roller
bearings. For vibration reasons, the input shaft has been
converted from a 2-bearing to a 3-bearing arrangement
(see arrow).
Improved transmission cooling through directed air flow in

the underbody of the vehicle, an open ventilator with
labyrinth sealing and waxed sealing rings completes the
optimization.

As a standard feature, the new 911 Carrera 4 (996) is
fitted with a six-speed manual transmission. This transmission was redesigned for the 911 Carrera 4 with cable
shifting and both units are largely identical.
The drive shaft has been extended towards the front for
the all-wheel drive of the front axle. The shaft emerges
through an additional opening in the front section of the
transmission housing and drives the front axle via a single
piece drive shaft and a central shaft.

Page 2.4

Drivetrain Repair – Sports Cars 6-Speed


911 (996)/Boxster S (986) Transmission
Transmission – G96.31 - 911 Carrera 4 (996)

Notes:

Additional 3rd Bearing on Input Shaft, See Arrow

The manual transmission for the rear wheel drive vehicle
and the four-wheel drive vehicle is based on the previous
911 (993) generation transmission. The manual transmission has been adapted to the higher engine torque of the
3.6 l engine with the dimensions and transmission ratios
remaining unchanged. The necessary higher dynamic

strength of the components has been achieved through
the use of higher alloy steels and precision shot blasting at
the pinion shafts. The aluminum die-cast housing has been
further optimized with regard to acoustics and vibration
and has been adapted to the new installation position due
to the standardization of the transmission mounts (manual
and Tiptronic).
The efficiency has been improved by reducing the drag
factor through decreased preloading on the tapered roller
bearings. For vibration reasons, the input shaft has been
converted from a 2-bearing to a 3-bearing arrangement
(see arrow).
Improved transmission cooling through directed air flow in
the underbody of the vehicle, an open ventilator with
labyrinth sealing and waxed sealing rings completes
the optimization.

Drivetrain Repair – Sports Cars 6-Speed

Page 2.5


911 (996)/Boxster S (986) Transmission
G96.00 Transmission Cutout

G96.01/G86.20 Transmission Cutout

Page 2.6

Drivetrain Repair – Sports Cars 6-Speed

911 (996)/Boxster S (986) Transmission
G96.30 Transmission Cutout

G96.31 Transmission Cutout

Drivetrain Repair – Sports Cars 6-Speed

Page 2.7


911 (996)/Boxster S (986) Transmission
Transmission Ratios – 911 Carrera 2/4 (996) G96.00/30

Transmission Ratios – Boxster S (986) G86.20

\
Gear Versus Road Speed Graph

Gear Versus Road Speed Graph

Transmission Ratios – 911 Carrera 2/4 (996) G96.01/31

Gear Versus Road Speed Graph

G96.00/30 & G86.20 Transmission Ratio

1st Gear
2nd Gear

3rd Gear
4th Gear
5th Gear
6th Gear
Rev. Gear

Z1

Z2

11
20
31
37
41
44
11

42
44
47
45
42
37
39

iz
Z2:Z1
3.818
2.200

1.516
1.216
1.024
0.841
3.545

ia
3.444
3.444
3.444
3.444
3.444
3.444
3.444

itot
iz:ia
13.149
7.577
5.221
4.188
3.527
2.896
12.209

V1000
km/h
8.8
15.4
22.3

27.8
33.0
40.2
9.5

V6000
km/h
53.1
92.2
133.3
166.8
198.0
241.2
57.2

Z1 = Number of teeth in 1st gearwheel in power flow of corresponding gear
Z2 = Number of teeth in 2nd gearwheel in power flow of corresponding gear
iz = Transmission ratio
ia = Final drive ratio
V1000 = Calculated vehicle speed at 1,000 rpm engine speed
V6000 = Calculated vehicle speed at 6,000 rpm engine speed
With 225/40 ZR 17 rear tires, rolling circumference 1,940 mm, (rdyn 295 + 1.5% - 2.5%)
Note:
The values in the transmission diagram are indicative and are based on a mean effective rolling radius. Slight deviations due to the tolerance
of the tires, change of rolling radius, wear, and slip of tires have not been taken into consideration.
Page 2.8

Drivetrain Repair – Sports Cars 6-Speed

911 (996)/Boxster S (986) Transmission
Gear Sets

Bearing Method

The transmission is a two-shaft transmission with an overhead drive shaft and hypoid drive assembly. The loose and
fixed gearwheels of all forward gears have been ground
and honed to reduce noise to a minimum. The shifting
gearwheel for the reverse gear has been shaved. Pairing
of the gearwheels was not necessary.

The input and output shafts are mounted radially and
axially in the transmission case by means of sealed double
angular contact ball bearings. The output shaft is mounted
in the transmission case cover by means of cylindrical
roller bearings and the input shaft is mounted using a
roller bearing sleeve.

All loose gearwheels have needle roller bearings. The fixed
gearwheels for the reverse gear, 1st gear, and 2nd gear
form part of the input shaft. The distance between the
axles of the input and output shafts is 87 mm. The reverse
gear is synchronized and can therefore be smoothly
engaged even when the vehicle is coasting slowly
forwards.
Input and Output Shafts - Boxster G86.20 and 911 (996 (G96.01/31
have an additional bearing in this area (red arrow).

Notes:

Gear Sets

Reverse Gear Components

The reverse gear is located in the transmission case
cover. The intermediate gearwheel of the reverse gear (1)
is mounted on a pin (2) by means of 2 needle-roller assemblies and secured in place with the bearing block (3). The
pin is inserted in the transmission case cover and is
supported at the transmission case cover by means of the
bearing block (3). The pin is held and secured by a bolt
screwed in from the transmission case cover (arrow).

Drivetrain Repair – Sports Cars 6-Speed

Page 2.9


911 (996)/Boxster S (986) Transmission
Synchronization, 1st/2nd Gear

Gear Retention

As with the 911 Carrera (993), the G 96 transmission has
double cone synchronization for 1st and 2nd gear. The
major advantage of this synchronization is that the shifting
forces are reduced by approx. 30 - 40 % compared to
single cone synchronization.

Gear retention is achieved by beveling the clutch body
toothing and shift sleeve toothing. When the torque is

transmitted, the beveled surfaces of the shifting sleeve
and the clutch body are pressed against each other so
that the shifting sleeve is moved to the clutch body or
loose gearwheel.

Functioning
Final Drive

Ring and Pinion

The synchronizing ring (2) and friction ring (3) rotate at the
same speed as the guide sleeve (4) and shift sleeve (5)
irrespective of the vehicle speed (drive shaft). The loose
gearwheel with clutch body (6) and the tapered ring (1)
rotate at the same speed as the engine.
If, during the shifting process, the shift sleeve is moved
axially along the guide sleeve, a moment of friction is
produced between the synchronizing ring and tapered ring
at the around the outside diameter and between the
friction ring and tapered ring around the inside diameter.
This moment of friction decelerates (1 - 2 shifting) or
accelerates (2 - 1 shifting) all parts rotating at the same
speed as the engine. Doubling the number of friction
surfaces considerably reduces the shifting forces.

The drive set is a hypoid drive. This means that the center
axis of the crown wheel is 12 mm above the center axis of
the drive shaft. Hypoid drives can (with the same crown
wheel size) transmit relatively high torques since the teeth
of the drive shaft have designed to be more robust. In

addition, the modified crown wheel bearing can be used at
lower diffraction angles along the drive shafts. The drive
shaft and crown wheel are toothed using the Oerlikon
method. The drive shaft has been hollow-drilled to reduce
weight. The diameter of the crown wheel is 196 mm. The
adjusting dimension E is 65 mm.
Limited-slip Differential
As standard equipment, the 911 Carrera 4 (996) has a
Porsche Stability Management (PSM). A mechanical
limited-slip differential would have a detrimental effect on
the functioning of the PSM. The 911 Carrera 4 (996)
cannot be equipped with a mechanical limited-slip differential.
Lubrication

Synchronization, 3rd - 6th and R. Gear
Synchronization for gears 3 - 6 and for the reverse gear is
identical to single cone synchronization. The synchronizing
rings for gears 3 - 6 are identical and have a molybdenum
coating. The synchronizing ring for the reverse gear is not
coated.

Page 2.10

The transmission is filled with 2.7 l of Shell Transaxle Oil.
The oil change interval is 90,000 miles. It is also approved
to use Mobil oil (Mobilupe PTX).

Drivetrain Repair – Sports Cars 6-Speed

911 (996)/Boxster S (986) Transmission
Gear Shifting

Notes:

The six forward gears and the reverse gear are arranged
in four shift gates. The 6th gear is located at the bottom
right of the shifting pattern.

A newly developed cable shift is used. This prevents
assembly movement and vibrations from being transmitted
to the gear-shift lever. In contrast to the previously used
gear-shift linkage, a shift and selector cable (which can be
subject to tensile and compressive loads) form the
connection between the gear-shift lever and the transmission. The advantages of this system are the small space
requirements, the low weight, and especially the effective
prevention of assembly movement and vibration being
transmitted to the gear-shift lever without detrimentally
affecting the precise shifting behavior.

Drivetrain Repair – Sports Cars 6-Speed

Page 2.11


911 (996)/Boxster S (986) Transmission
Functioning

Gear Detent
A central gear detent is provided by the internal

mechanism (7). Each individual shift rod is also arrested by
separate springs and balls (9).

Selector Lever

The selector cable is connected to the selector lever shaft
(1) to allow preselection of the gear level. The longitudinal
movement is converted into rotary movement via an angle
drive (2). This causes the internal shift rod (3) inserted in
the angle drive and the internal shift finger (4) attached to
the rod to rotate. As a result, the internal shift finger
catches the corresponding shift rod. The gear levels are
arrested with the cam (5).

Shift Interlock
A moving locking plate (10) is attached to the transmission
housing to ensure that only one gear can be engaged at
any one time. This plate is designed such that, when one
shift rod is moved, all others are locked.
External Shift Lever

The shift cable is connected to the external shift lever (6)
to allow the gear to be engaged. The external shift lever is
in turn connected to an internal mechanism (7) which
engages in a shift shaft (8) which causes the respective
shift fork to be moved.

External Shift Lever

The external shift lever attached to the transmission has

two weights to increase mass inertia and to prevent vibrations.

Page 2.12

Drivetrain Repair – Sports Cars 6-Speed


911 (996)/Boxster S (986) Transmission
Transmission Housing

Notes:

Since the transmission case has two bearing points, it is
formed from two parts. The case parts are produced from
the aluminum alloy GD-AL-Si9Cu3 using the die-cast technique.

Drivetrain Repair – Sports Cars 6-Speed

Page 2.13


911 (996)/Boxster S (986) Transmission
Viscous Multi-disc Clutch – 911 Carrera 4 (996)
In order to prevent high temperatures at the viscous multidisc clutch, the unit has been integrated in the front-axle
final drive. No additional space in the manual or Tiptronic
transmission has had to be provided as a result of this
measure.

However, since tire slippage exists whenever drive torque
is transmitted, it is possible to speak of a permanent allwheel drive with variable torque distribution to the front

axle of approx. 5 - 40%.

In contrast to the previous model, the new 911 Carrera 4
(996) has a stiffer viscous clutch. This is achieved by
using a more viscous silicon oil. This measure results in a
further improvement with regard to traction. The internal
toothing has been modified in order to prevent confusion
between the new and old viscous clutches.
Functioning

Viscous Clutch

The housing (1) (connected to the drive shaft of the frontaxle final drive) is supported by plain bearings in the hub
(2) (connected to the central shaft) and the interior is
sealed with sealing rings.
The viscous multi-disc clutch is filled with a precisely
defined quantity of high-viscosity silicon oil. The clutch is
sealed which means that it is not possible to add more silicon oil or check the oil level. If there is a speed differential
between the outer and inner discs, a torque is transmitted
from the fast to the slow rotating side due to the internal
fluid friction.
The discs are fully separated by the oil so that they are not
subjected to abrasion or wear. Since distribution occurs
according to the difference between the traction slippage
at the front and traction slippage at the rear wheels and to
the resulting speed differential, a variable torque distribution exists, i.e. the distribution adapts to the given requirements.

Page 2.14

Drivetrain Repair – Sports Cars 6-Speed

911 (996)/Boxster S (986) Transmission

Front Axle Differential (Z96/00) – 911 Carrera 4 (996)

Notes:

The axle is driven via a spiral bevel gear which is ground
and lapped to narrow the production tolerances. To reduce
drag losses, grooved ball bearings (1) are used in the
differential gear instead of tapered roller bearings. A hole
with M8 thread (2) is drilled into the side cover of the
differential. This is required to allow noise measurements
to be carried out during production and can be disregarded by Service personnel. There is a bleeder hole (3) in
the underside of the long-neck tube. This hole should not
be sealed. The discharge of transmission oil from this hole
indicates that the sealing ring (4) is damaged. The frontaxle final drive is filled with Shell Transaxle Oil 75W90.
Performance Test
Performance tests should only be carried out on four-roller
test stands with speed decoupling. If testing is performed
on two-roller test stands, the propeller shaft must first be
removed.

Drivetrain Repair – Sports Cars 6-Speed

Page 2.15