A/T - New Style Thrust Bearing Assembly
Number: 84-100Section: 7A (VIIc)
Date: April, 1984
Subject: THRUST BEARING ASSEMBLY, FINAL DRIVE SUN GEAR TO DIFFERENTIAL
CARRIER INFORMATION
Model and Year: ALL 1980-84 THM 125/125C
TO: ALL CHEVROLET DEALERS
Since October, 1983, a new larger thrust bearing assembly (final drive sun gear to differential carrier) went into production in the 1984 model THM 125/125C transmission, using the 2.84 ratio final drive and differential assembly..
FIGURE 1 - Thrust Bearing:
FIGURE 2 - Thrust Bearing:
The difference between the two (2) thrust bearing assemblies is the outer diameter size. Also the carrier bearing surface is machined larger to accommodate the larger outer diameter bearing. Thrust bearing, P/N 8646254 (Figure 1), is larger than thrust bearing, P/N 8628962 (Figure 2).
The two (2) thrust bearing assemblies are not interchangeable and damage to the final drive could result if the bearings are mixed. To assure correct usage, refer to the following service procedure.
SERVICE PROCEDURE
1. After removing the thrust bearing assembly from the final drive differential carrier, measure the outer diameter using a standard ruler as shown in Figures 1 and 2.
2. If the outer diameter is 2 1/8" order service package 8646254. If the outer diameter is 2" order part 8628962.
NOTICE: The larger thrust bearing assembly, P/N 8646254, was previously used on only the 3.06 and 3.33 ratio final drive assemblies, but now is used on all models.