A/T - Revised Sprocket Support, Chain Scavenging Scoop
89Pontiac24Bulletin Number: 90-7-16
Reference Number: 977157
Publish Date: 11/89
Subject: NEW DRIVEN SPROCKET SUPPORT AND CHAIN SCAVENGING SCOOP
Models
Affected: 1990 ALL MODELS WITH 4T60/440-T4
Figure 1 - Previous And New Driven Sprocket Support:
CHANGE TO ASSEMBLY COMPONENTS: (Figure 1)
A new driven sprocket support and chain scavenging scoop is used in production on 1990 models equipped with a HYDRA-MATIC 4T60 (THM 440-T4). The new driven sprocket support requires the chain scavenging scoop to be about 1/3 the length of the previous scoop.
IMPORTANT:
The new driven sprocket support will service past models, but the new length of the chain scavenging scoop must be used with it. The previous scoop will not fit. Do not leave out. This will cause durability concerns.
Do not use the new length of the chain scavenging scoop with the previous driven sprocket support assembly. This will cause durability concerns.
DATE OF PRODUCTION CHANGE:
Starting August 16, 1989 (Julian Date 228) all HYDRA-MATIC 4T60 (THM 440-T4) will be built with the new driven sprocket support and chain scavenging scoop.
Figure 2 - Cutting Previous Scoop To Fit New Support:
SERVICE PROCEDURE:
The new driven sprocket support and chain scavenging scoop will assemble the same way as the previous. The previous scoop can be cut to fit the new support. Lay the previous scoop on the actual size scoop in Figure 2 and cut at the line. Smooth off the rough cut edge.
SERVICE PARTS INFORMATION:
Parts are expected to be available on 11-30-89. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while the 400 control is in place.
SERVICE NOTES:
The service part number did not change from the previous to the new driven sprocket support assembly. Either style may be available until the previous style stock is depleted; then the new style support will be the only style available. Cut the previous chain scavenging scoop for the new style support following procedures listed in this Service Bulletin.
SERVICE MANUAL REFERENCE:
Refer to the appropriate Service Information Manual for service procedures.