A/T - Auxiliary Valve Body/Gasket Revised Servicing
Number 83-I-179 Section 7 Date 3/84Subject: NEW AUXILIARY VALVE BODY AND AUXILIARY VALVE BODY GASKET - ALL THM 125-C TRANSMISSIONS
FIGURE 1 - Auxiliary Valve Body:
FIGURE 2 - Valve Body Gasket:
FIGURE 3 - Valve Body Cover:
During September, 1983 all THM 125-C transmissions were built with a new auxiliary valve body and valve body gasket. The new auxiliary valve body does not have an orifice plug hole (Figure 1). The auxiliary valve body gasket is made out of a new material and has three holes made larger (Figure 2).
The changes to the gasket eliminate a no [1][2]torque converter clutch release (TCC) or no TCC apply condition that resulted from incorrect cup plug, mispositioned cup plug or eroding gasket.
NOTE: The only interchangeable part is the auxiliary valve body cover (Figure 3). The new auxiliary valve body gasket must be used with the new auxiliary valve body. The past auxiliary valve body gasket must be used with the past auxiliary valve body.
When servicing any model THM 125-C transmission auxiliary valve body refer to the following procedure:
1. Identify the auxiliary valve body being serviced (past or new). See Figure 1.
2.. If the past auxiliary valve body is being serviced refer to Chart 1. If the new auxiliary valve body is being serviced refer to Chart 2.
CHART 1
PART BEING REPLACED PART NUMBER
Auxiliary Valve Body Cover Gasket 8653947
Auxiliary Valve Body Cover 8643645
Auxiliary Valve Body Orifice Plug 8623796
Auxiliary Valve Body (past design not serviced) New auxiliary valve body must be used,
order Service Package 8653946.
CHART 2
PART BEING REPLACED PART NUMBER
Auxiliary Valve Body Cover Gasket 8643863
Auxiliary Valve Body Cover 8643645
Auxiliary Valve Body Models
BF, BL, CE, CA, CB, CF, CL, CK, CT,
CC, PE, PD, PG, PJ, PW, PF 8653946
Service Package
EM, EN, EW, HC, HS, HV, HY, OP 8653945
Service Package
Service Package 8653946 contains:
1 8643865 Auxiliary Valve Body
1 8643863 Gasket Aux. Valve Body
1 8643645 Cover Aux. Valve Body
Service Package 8653945 contains:
1 8643864 Body Auxiliary Valve
1 8643863 Gasket Aux. Valve Body Cover
1 8643645 Cover Aux. Valve Body
Only the Auxiliary Valve Body Cover, Auxiliary Valve Body Cover Gasket, and Auxiliary Valve Body Orifice Plug can be ordered separately.
When servicing any auxiliary valve body inspect it for erosion around hole number 1 in Figure 2. If the gasket is eroded then replace the auxiliary valve body cover along with the required gasket.
If the auxiliary valve body being serviced needs the orifice plug replaced due to damage or missing follow the procedure listed below.
A. If the orifice plug is still in the auxiliary valve body, remove it with a 7/32 screw extractor.
B. Install a new orifice plug (Part Number 8623796) using a 5/16" punch to start the orifice plug in the hole. Then use a 3/8" punch and seat the plug flush with the wall Figure 1.