A/T - THM 700R4 Service/Parts Information: Overview
GMC NUMBER: 87-T-28
SECTION: 7A - Automatic Transmission
DATE: February, 1987
SUBJECT: SERVICE AND PARTS INFORMATION FOR TRANSMISSIONS WITH AND WITHOUT
AUXILIARY ACCUMULATOR VALVE BODY ASSEMBLIES
MODELS: 1987 LIGHT DUTY MODELS WITH 700-R4 AUTOMATIC TRANSMISSIONS
Bulletin Covers:
A 1987 model THM 700-R4 transmission may be built with or without an auxiliary accumulator valve body assembly (auxiliary valve body). Identification, service procedures, new parts and fluid passage information for this change are provided in this bulletin.
IMPORTANT: The 1987 GM Service Parts Catalog printed in September, 1986 gives information for a 1987 transmission built with an auxiliary valve body. Use of this printed information on a transmission built without an auxiliary valve body can create a misbuild.
Additionally, other changes to the 1987 THM 700-R4 transmission that affect service procedures and/or new part information are also included.
Figure 1 - Date of Change for 1987 THM-R4 Transmission Models With Auxiliary Valve Body:
Date of Changes: (Figure 1)
By October 6, 1986, (Julian Date 279) all 1987 THM 700-R4 transmission models were built with the auxiliary valve body. Also, all 1987 Service Replacement Transmission Assembly (SRTA) models are built with the auxiliary valve body.
Figure 2 - Auxiliary Valve Body Location:
Service Action
To determine which service procedures and parts to use on a 1987 THM 700-R4 assembly with a Julian Date between 198 and 279, remove the transmission oil pan and look for an auxiliary valve body (refer to Figure 2).
Service Parts Information:
If the auxiliary valve body is present, refer to 1987 GMSPO (General Motors Service Parts Operation) Catalog Listing dated September, 1986.
If the auxiliary valve body is not present, refer to GM Service Parts "Action" Bulletin #86-58.
Service Manual Reference:
1987 Service Manual procedures and illustrations in manuals printed prior to November, 1986 may not include information provided in this bulletin.
SUMMARY OF BULLETIN INFORMATION
DETAILS BEFORE AFTER
ON DATE OF DATE OF
SUBJECT PAGE CHANGE CHANGE
Auxiliary Valve Body Assembly 4 Not Used Used
- turbine shaft seals Scarf Cut Solid
Fluid Passage Identification 9-16 ----- -----
Oil Pump Assembly 17 7 Vane 10 Vane
Plugged Hole Add Feed Pipe
Forward Clutch Assembly 19 Stack Up: Stack Up:
thick spacer no spacer
& thin apply or thin apply
narrow sprag: wider sprag: wear plate no wear plate
thrust washer no thrust washer
Lo And Reverse Roller Clutch 23 Used Pre-SOP Wider Roller
1987 Models Elements
Oil Pan 24 Round Magnet Square Magnet
Dimpled Pan Deeper Pan
Temperature Switch 25 Not Used SOP Some Models