Transfer Case - High Shift Effort: Overview
90chevy24GMC NUMBER: 90-7D-87
GROUP: 7D-TRANSFER CASE
DATE: AUGUST, 1990
CORPORATE
NUMBER: 067407
SUBJECT: HIGH TRANSFER CASE SHIFT EFFORT, INSTALLATION OF EASY SHIFT PACKAGE
MODELS: 1988-90 K1, K2, K3 TRUCKS EQUIPPED WITH NEW PROCESS 241 TRANSFER CASE
Some 1988-90 K-Trucks may experience high transfer case shift effort or blockouts when "shifting on the fly" from 2H to 4H under cold weather conditions (usually less than 32 degrees Fahrenheit). This condition may be corrected by the installation of the synthetic 75W90 gear lube described in GMC Truck Service Bulletin 89-T-90. If the installation of this fluid does not result in a satisfactory shift effort an "Easy Shift" package may be installed in the transfer case. This package was. installed in production early in the 1990 model year and will provide reduced transfer case shift effort under cold weather conditions.
INVOLVED VEHICLES All 1988-90 K1, K2, K3 trucks equipped with New Process 241 transfer case and built prior to the VIN Breakpoints listed below: