Firebird V8-305 5.0L (1982)
Case: Technical Service Bulletins
A/T - Modified Case 2nd, 3rd, 4th Clutch Pressure Taps
Bulletin Number:
89-7-22
Reference Number:
977107
Publish Date:
3/89
Subject:
NEW CASE ASSEMBLY - REMOVAL OF 2ND, 3RD AND 4TH CLUTCH PRESSURE TAPS.
Models
Affected:
1982-89 SAFARI WAGON AND FIREBIRD MODELS WITH 700R4 4L60 TRANSMISSIONS
FIGURE 1 - REMOVAL OF 2ND, 3RD AND 4TH CLUTCH PRESSURE TAPS
BULLETIN COVERS:
(Figure 1)
Service information for new THM 700-R4/HYDRA-MATIC 4L60 Case assemblies. The new case will no longer have the 2nd, 3rd or 4th clutch
pressure taps. Mainline pressure tap remains unchanged. The clutch pressure taps require case bosses to bring the channeling to the exterior of the case
and provide an area to tap and plug the pressure ports. The casting process necessary to provide the case bosses and channeling increase the chance of
case porosity in those areas. By removing the clutch pressure taps, the casting can be changed to reduce incidences of case porosity and leaks.
FIGURE 2 - THM 700-R4/HYDRA-MATIC 4L60 TRANSMISSION IDENTIFICATION INFORMATION
DATE OF PRODUCTION CHANGE:
(Figure 2)
Starting December 2, 1988 (Julian Date 337) all THM 700-R4/HYDRA-MATIC 4L60 transmissions were built without drilling and tapping the 2nd,
3rd, or 4th clutch pressure taps. The case bosses will be removed through normal die maintenance.
