A/T - Pressure Regulator Bushing Pin Design Change

Bulletin No. T 84-21
File In Group 7
Number 90
Date Dec. '83

SUBJECT: PRESSURE REGULATOR BUSHING PIN DESIGN CHANGE - THM 325-4L

MODELS AFFECTED: 1983 ELDORADO AND SEVILLE

FIGURE 1 - Coiled Spring Pin:

FIGURE 2 - Larger Solid Steel Pin:

Beginning early in April, 1983 production the THM 325-4L transmission case was changed along with the coiled spring pin (refer to Figure 1) used to retain the pressure regulator valve bushing in the case. A larger solid steel pin (refer to Figure 2) is now used. This change was made to eliminate the possibility of case face distortion during assembly. Due to different sizes, these two pins cannot be used interchangeably. Furthermore, the new solid pin is a slip fit in the transmission case and may fall out if the transmission is rolled over; loss of this pin would enable the pressure regulator bushing to lose proper orientation, resulting in the loss of proper pressure regulator valve operation.
If replacement of either pin is required, use the following numbers to order the correct pin from GMWDD:
Figure 1 - Coiled Spring P/N 9437415
Figure 2 - Solid Pin P/N 141202