A/T - Harsh 1-2 Upshift, May Require Cold Soak
Number: 92-318-7ASection: 7A
Date: NOV. 1992
Corporate Bulletin No.: 277135R
ASE No.: A2
Subject:
HARSH 1-2 UPSHIFT
Model and Year:
1992 CAPRICE, CAMARO AND CORVETTE
1992 C/K, G, L/M, S/T TRUCKS
TRANSMISSION APPLICATIONS:
1992 HYDRA-MATIC 4L60
TRANSMISSION MODELS:
2AAM, 2ACM, 2ADM, 2AKM, 2BAM, 2BBM, 2BCM, 2BHM, 2BRM, 2BWM, 2CAM, 2CBM, 2CCM, 2CFM, 2CHM, 2CJM, 2CPM, 2FTM, 2FUM, 2FZM, 2HBM, 2HDM, 2HLM, 2KHM, 2KJM, 2KMM, 2LHM, 2MDM, 2MJM, 2MSM, 2SHM, 2TAM, 2TBM, 2TLM, 2TWM, 2WAM, 2WBM, 2WCM, 2YAM, 2YCM
SUBJECT:
Harsh 1-2 Upshift; Install Service Package
VEHICLE APPLICATIONS:
B, F, Y Cars C/K, S/T Trucks G, L, M Vans
CONDITION (Figure 1):
Some vehicles 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 due to 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 Transmission Models
8687992 2AAM, 2ACM, 2BAM, 2BBM, 2BCM, 2BHM, 2BRM, 2BWM,
2CAM, 2CBM, 2CCM, 2CFM, 2CHM, 2CJM, 2FTM, 2FUM,
2HBM, 2HLM, 2KHM, 2KJM, 2KMM, 2LHM, 2MJM, 2SHM,
2TLM, 2TWM, 2WAM, 2WBM, 2WCM
8688900 2ADM, 2AKM, 2CPM, 2FZM, 2HDM, 2MDM, 2MSM, 2TAM,
2TBM, 2YAM, 2YCM
WARRANTY INFORMATION:
Labor Operation Number: T7601 (Valve Body, R&R).
Labor Time:
C/K, G, L/M, S/T Trucks 1.8 hrs.
Labor Time:
Caprice 1.7 hrs.
Camaro 1.4 hrs.
Corvette 1.3 hrs.
Corvette with folding top add 0.6 hrs.
SERVICE MANUAL REFERENCE:
Refer to the HYDRA-MATIC 4L60 Unit Repair Section of the appropriate service manual for repair information.