G 2500 3/4 Ton Van V6-262 4.3L VIN Z (1992)
Torque Converter: All Technical Service Bulletins
A/T - Loss of Drive Gears in All Ranges
Group Ref.: 7 - Transmission
Bulletin No.: 367104
Date: August, 1994
SUBJECT:
LOSS OF DRIVE GEARS IN ALL RANGES (INSTALL SRTA TRANSMISSION AND CHECK DRIVELINE WORKING ANGLES)
MODELS:
1991-93 CHEVROLET AND GMC TRUCK P3 (32) MOTORHOMES WITH 4L80E/4L80-EHD AUTOMATIC TRANSMISSIONS (RPO MT1)
CONDITION:
Some vehicles may exhibit a loss of drive gears in all ranges.
CAUSE:
A loss of drive in all ranges may be caused by a fractured transmission turbine shaft. A fracture may occur at the forward clutch feed hole of the turbine
shaft due to 1) extreme service applications and/or
2) driveline angle misalignment caused by after-market rear suspension components.
CORRECTION:
Remove the torque converter assembly, inspect the transmission turbine shaft for fractures. The turbine shaft will spin easily if it is fractured. If the
turbine shaft is fractured, install a SRTA Transmission Assembly, check vehicle GVW and rear suspension components and correct driveline working
angles. If the turbine shaft is not fractured, refer to Section 7 of the P model Service Manual for other causes of lack of drive.
SERVICE PROCEDURE:
Important:
Driveline working angles must be corrected by either a Chevrolet, GMC Truck or motorhome dealer on motorhomes that experience a transmission
turbine shaft fracture. Service Replacement Transmission Assemblies (SRTA's) installed to fix turbine shaft fractures are not necessarily the
responsibility of General Motors. See steps 9 and 11 of the following procedures for further details. GM Consolidated Fleet Service or the GMC
Truck District Service Representative will review each case and assist In contacting the coach manufacturer for participation with the required repairs
and adjustments. Driveline angle adjustment for vehicles equipped with non-GM rear suspensions should be the responsibility of either the customer
or the body builder.
1.
Securely block front and rear wheels.
2.
Completely remove the transmission from the vehicle. Refer to transmission replacement in Section 7A of the P Model Service Manual or the
Light Duty Forward Control and Motorhome Chassis Service Manual.
3.
With the torque converter assembly removed, inspect the transmission turbine shaft for fracture(s) (Figure 1). The turbine shaft will spin easily if it
is fractured. The turbine shaft will not move easily if it is not fractured.
4.
If the turbine shaft is NOT fractured, refer to Section 7A of the P Model Service Manual or the Light Duty Forward Control and Motorhome
Chassis Service Manual for possible other causes for loss of drive in all ranges. Repair as needed and continue with step 21.
5.
If the turbine shaft is cracked, install a SRTA Transmission Assembly. Refer to the 4L80E/4LBO-EHD SRTA mod2l replacement information in
the appropriate GM parts catalog. Also refer to Transmission Replacement in Section 7A of the P Model Service Manual or the Light Duty
Forward Control and Motorhome Chassis Service Manual.
Important:
All returned Hydra-Matic 4L80-E transmissions will be disassembled and Inspected In an effort to increase product Integrity. Attempting repairs
