S15/T15 Sonoma P/U 2WD L4-2.2L VIN 5 Flex Fuel (2001)
Shift Cable: Technical Service Bulletins
A/T - Slipping/Missed Shifts Diagnostic Tips
File In Section: 07 - Transmission/Transaxle
Bulletin No.: 01-07-30-043
Date: December, 2001
INFORMATION
Subject:
Diagnostic Tips for Slipping or Missing Second, Third and/or Fourth Gear
Models:
2001-2002 Chevrolet Camaro, Corvette
2001-2002 Pontiac Firebird
2001-2002 Chevrolet and GMC C/K Pickup and Utility Models
(Silverado, Sierra, Suburban, Tahoe, Yukon, Yukon XL)
2001-2002 Chevrolet and GMC G-Van Models (Express, Savana)
2001-2002 Chevrolet and GMC M/L-Van Models (Astro, Safari)
2001-2002 Chevrolet and GMC S/T Pickup and Utility Models
(S10, Sonoma, Blazer, Jimmy)
2002 Chevrolet and GMC S/T Utility Models (New Style) (TrailBlazer, Envoy)
2002 Cadillac Escalade
2001-2002 Oldsmobile Bravada
Recently, a study was completed to determine the causes of slipping/missing 2nd, 3rd or 4th gear in the 4L60/4L65-E transmission family. This study
was conducted using transmissions which were determined by dealership technicians as having a slipping/missing shift. The transmissions used were
from vehicles with less than 19,000 km (12,000 mi) and the slipping/missing shift condition was verified during a test drive by dealership personnel
before the transmission was removed from the vehicle. Eight items were found to cause the majority of the slipping/missing shift concerns. These eight
items are listed below in the order of frequency that they were found.
^
Chips in the servo feed oil passage, orifice # 7 in the spacer plate.
^
Cut forward clutch piston inner seal.
^
Cut 3/4 clutch piston outer seal.
^
Input housing orifice cup plug blown out.
^
Input housing cracked or broken.
^
Mislocated valve body to spacer plate check ball(s).
^
Case damaged at the 2nd clutch apply piston pin bore causing the pin to drag/stick in the bore.
^
Input housing air bleed orifice cup plug with a check ball that does not seal.
In addition to the above items, a misadjusted shift cable has been found to cause these types of concerns. When attempting to correct a slipping/missing
second, third or fourth gear, the items listed above should be inspected as possible causes. It is also important to reference the appropriate Service
Information for additional possible causes of these concerns.
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