Delta 88 V6-3800 3.8L (1988)
FIGURE 3 - DESIGNATED HIGH ALTITUDE COUNTIES*
This bulletin covers harsh 3-2 detent downshift that occurs at high altitudes for some 1988 A, C, E and H cars equipped with a 3.8L or 3800 engine and a
THM 440-T4 transaxle. This condition may be corrected by replacing the 3-2 control valve spring (341) shown in Figure 2. Refer to Figure 3 for areas
designated as High Altitude Counties in the continental United States.
Prior to replacing the 3-2 control valve spring, other items to be inspected that affect transaxle operation and may contribute to harsh shift conditions are:
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vacuum leaks (low vacuum supply to the vacuum modulator). Required vacuum is 44-61 kPa (13-18 in. Hg.)