Suburban 3/4 Ton 4WD V8-305 5.0L (1986)
Fluid Pump: All Technical Service Bulletins
A/T - Leaks From the Oil Pump Body
CORPORATE NUMBER: 677119R NUMBER: 86-T-124
GROUP:
7A - Automatic Transmission
IMPORTANT - All Service Personnel Should Read
DATE:
November, 1986
SUBJECT:
FLUID LEAKS FROM THE OIL PUMP BODY
MODELS:
1984-86 LIGHT DUTY MODELS WITH 700-R4 AUTOMATIC TRANSMISSIONS
Some 1984 through 1986 THM 700-R4 transmissions may exhibit fluid leaks from the oil pump body caused by walk-out of the pump body bushing and
helix seal assembly. Several changes have been made to this area.
Figure 1 - THM 700-R4 Transmission Identification Information
Figure 2 - OIL PUMP BODY ASSEMBLY
Beginning October 10, 1985 (Julian Date 283, see Figure No. 1) a new front pump helix seal assembly with a 270 degree lip was introduced. In addition,
all THM 700-R4 transmission models incorporated a machine step (smaller bore diameter) in the oil pump effective January 6, 1986 (Julian Date 006) as
shown in Figure No. 2. The latest change, effective February 11, 1986 (Julian Date 042), a new front pump seal retainer was added to eliminate walk-out
of the pump body bushing and helix seal assembly.
