A/T - Harsh 1-2 Upshift Untill System at Operating Temp
Bulletin: 92-74L60-9ADate: Nov. '92
Ref.No.: 92-315-74L60
Corp.Ref.No.: 277135R
SUBJECT:
HARSH 1-2 UPSHIFT (INSTALL SERVICE PACKAGE)
MODELS AFFECTED:
1992 ROADMASTER WITH 1992 4L60 TRANSMISSION
THIS BULLETIN IS BEING REVISED TO CORRECT THE LABOR OPERATION NUMBER. PLEASE DISCARD BULLETIN NUMBER 92-74L60-9.
CONDITION: (Figure 1)
Some Roadmasters equipped with a 1992 HYDRA-MATIC 4L60 transmission built between Julian Date 061 (March 1, 1992) and Julian Date 171 (June 19, 1992) may experience a harsh 1-2 upshift.
NOTE:
Once the transmission is brought to operating temperature, the condition may not be able to be reproduced until a "cold soak" (overnight) is performed.
CAUSE:
The above condition may be caused by a tapered 1-2 accumulator sleeve. The tapered bore may cause the 1-2 accumulator valve to stick in the bottom of the bore.
CORRECTION: (Figure 2)
To improve the 1-2 shift, install the service package listed in this bulletin. A 1-2 accumulator valve and 1-2 accumulator valve sleeve (which, normally, is not serviceable) is included in the package.
SERVICE PARTS INFORMATION:
Package Number: 8687992
Parts are currently available from GMSPO.
WARRANTY INFORMATION:
Labor Operation Number: T7601 (Valve Body, R&R or Replace)
Labor Time: 1.8 hr.