A/T - New 2-4 Servo Cover and Seal

Number 83-I-124A Section 7 Date 3/84

Subject: NEW 2-4 SERVO COVER AND SEAL - THM 700-R4 TRANSMISSION SUPPLEMENT TO DEALER SERVICE BULLETIN 83-1-124

FIGURE 2 - Servo Cover "O" Ring Location:

Beginning April, 1983 all THM 700-R4 transmissions were built with a new 2-4 servo cover and seal. This change provides a tighter fit between the case servo bore and the 2-4 servo cover.

The new servo "O" ring (Part Number 8647351) is identified with a green stripe. This is to distinguish it from the past "O" ring (Part Number 8642112) which is still used on the second apply piston. Refer to Figure 2, numbers 14 and 21 for correct location of "O" rings.

NOTE: The past servo "O" ring (Part Number 8642112) cannot be used with the new servo cover, if used together they will leak.

FIGURE 1 - 2-4 Servo Cover Assembly:

Service Information:

If a leak is found at the 2-4 servo cover:

1. Remove the 2-4 servo cover and "O" ring seal.

2.. Check the case servo bore for sharp edges especially at the recessed slots. See Figure 1.

3. Check the case servo bore for burrs, nicks or damage on sealing wall. If damage is found replace the case.

4. Check the 2-4 servo cover for porosity or damage. If required replace with Part Number 8642979 which will contain a new 2-4 servo cover and "O" ring seal.

5. If it is necessary to replace only the "O" ring seal, use Part Number 8647351.

6. When installing the 2-4 servo cover and "O" ring seal, lubricate the seal with petrolatum or equivalent and use care not to cut the seal during installation.