C 3500 Truck 2WD V8-305 5.0L (1988)
Shifter M/T: All Technical Service Bulletins
M/T - Noises In Forward Gears/Shift Lever Rattle
Number:
88-295-7B
Section:
7B
Date:
JULY, 1988
Subject:
TRANSMISSION NOISES IN FORWARD GEARS/ SHIFT LEVER RATTLE
Model and Year:
1988 C/K TRUCKS WITH HM-290 MANUAL TRANSMISSION
FIGURE 1 - HM-290 TRANSMISSION IDENTIFICATION INFORMATION RPO MC0/MG5
TO:
ALL CHEVROLET DEALERS
This bulletin covers 1988 C/K Trucks equipped with a HM-290 4 or 5 speed manual transmission which may experience noises in any or all forward
gears, or a condition of shift lever rattle/buzz and/or excessive vibration of the shift lever (Figure 1). Some movement of the shift lever is normal,
especially with the 4.3L engine, unless it causes a rattling noise. Any of the above conditions could be caused by excessive clearance in the shift lever
housing assembly transmitting vibration and rattle to the driver compartment. The condition(s) will increase with engine RPM and be in any or all gears,
including neutral. conditions explained as shift lever rattle/buzz and excess vibration of the shifter can be repaired by installing a new shift lever housing
assembly: The new shift lever housing assembly uses compression grommets at the pivot points, eliminating the chance of excess clearances due to
improper shim selection.
IMPORTANT:
A slight gear rattle at low engine RPM (800-1200 RPM) is normal to all manual transmissions. The service repair described above will
only reduce the rattle condition due to improper shimming.
