Porsche 928 Workshop Manual page 1124

38
Automatic Transmission/Gears, Valve Body
928
Condition:
Strong jolt when engaging selector lever in "D" and "R".
Cause/Correction:
1. Adjust idle speed and CO level to specifications.
2. Check modulating pressure, correcting if necessary
3. Check whether spring is installed underneath valve
ball (5) in shift valve housing (see page 38 126).
4. Check vacuum line and connections for leaks.
5. Check whether pressure acceptance piston in shift
valve housing moves easily and is in correct installed
position, replacing shift valve housing if necessary.
Note:
If there is a hard engagement jolt when quickly shifting back and forth
between "N" and "D" several times, there is no fault. The pressure pick-up
requires a running time of approx. 2 seconds. If this time is given, the
engagement jolt will also be correct.
Condition:
Strong jolts when changing gears.
Cause/Correction:
1. Check modulating pressure, adjusting if necessary.
2. Check vacuum line and connections for leaks
a
38-114 Troubleshooting
Printed in Germany