A/T - Revised Service Procedures, Production Change
NUMBER: 92-U-69CORP.REF.NO: 377102
DATE: February 1993
SECTION: 7A, 4L60
SUBJECT:
TRANSMISSION UNIT REPAIR INFORMATION
MODELS/YEARS:
1992 CUSTOM CRUISER AND BRAVADA
WITH THE 4L60 TRANSMISSION
BULLETIN COVERS:
New Product Information for 1992 HYDRA-MATIC 4L60 transmissions. This information has been updated since publication of the 1992 Service Manual and should be noted accordingly. Be certain to familiarize yourself with these updates to properly repair the 1992 HYDRA-MATIC 4L60 transmission.
DATE OF PRODUCTION CHANGE:
On August 14, 1991 (Julian Date 226), the HYDRA-MATIC 4L60M transmissions were built with a new calibration that changed the TV link line-up. The changes included a new TV limit valve, a new TV limit valve spring, and eliminates the TV limit plug. Also included is an updated line pressure check chart and an updated 2nd apply piston and housing application chart.
SERVICE MANUAL REFERENCE:
Update your 1992 Service Manuals with the information.
Line Pressure Check Procedure
Control Valve Assembly Exploded View
Apply Piston, And Servo Assembly Housing Application
^ Cover (15) for porosity or damage.
^ Seals for:
- Nicks or cuts.
- Freeness in the seal groove.
^ Springs for distortion.
^ Pin for wear or burrs.
Important
^ Check servo bore in the case for any wear which may cut the servo seals.
Measure
Figure 121
1. Measure piston (25) dimension *A.
2. Measure housing (22) dimension **B.
3. Check model application.