GM Full Size Vans 1987-1997 Repair Guide

General Information


A number of transmission are available depending on selected drivetrain combinations and GVW packages. They are the Turbo Hydra-Matic 400 3-speed, the Turbo Hydra-Matic 700R4 4-speed overdrive, the 4L60E and 4L80E electronically controlled transmissions.

In 1990 the designations were changed, while the transmissions remained essentially the same. The THM 400 3-speed became the 3L80; the THM 700R4 became the 4L60.