Porsche 928 Workshop Manual page 804

9 28
Automatic Transmission / Gears, Valve Rody
38
Condition: Strong jolts whtln changing gears
Correction: I. Check modulating and operating prcrrurcs. adjusting
modulating pressure if n~crsaary. If operating pressure
is too high, replace shift valve housing.
2. Check vacuum liilc and connections for leaks.
3. Scrvicc control valve for converter adaptation.
Condition Strong jolt in downshift from 3rd to 2nd gear
Correction: 1. Replace seal on release end of 8 2.
2. Replace brake band piston B 2.
Condition: No upshifts
Correction: 1. Check govemor pressure. If there is no govrrnur pressure
reading, continue with point 1. If governor pressure
is correct, continue with point 2.
2. Disassemble, clean and service centrifugal guvernor.
3. Disassemble and clean shift valve housing. replacing if
necessary (use new sealing bushings on plug tuba).
Conditiun:
No upshift on cold transmission. uprbifts
okay nftcr short
dirtancc
Correction: 1. Replace shift valve housing (use new sealing bushings
on
plug
tubes).
Primed in Germany - I. 1978
Troublerhwting
38 15