Suburban 1/2 Ton 2WD V8-379 6.2L DSL (1986)
Technical Service Bulletin # 86C107B
Date: 861201
Campaign - Transfer Case Adapter Mis-Machined
NUMBER:
86-C-10
GROUP:
7B -Manual Transmission
DATE:
December, 1986
SUBJECT:
TRANSFER CASE ADAPTER MIS-MACHINED
MODELS:
1986 K35 LIGHT DUTY MODEL TRUCKS EQUIPPED WITH 4 SPEED MANUAL TRANSMISSIONS (RPO M20)
General Motors has determined that transmission fluid may leak from the transfer case adapter where it meets the transfer case on some 1986 K35
models, equipped with a 4 speed manual transmission. This condition may be caused by an impropery machined transfer case adapter. The bore of the
adapter at the transfer case end should be machined to a depth of 25 mm. Units that develop a leak at this area may have, an adapter bore machined to
only 14 mm which does not seat properly against the transfer case. To correct this condition, adapters that have been improperly machined must be
replaced.
Vehicles Involved
Involved are certain 1986 K35 light duty model trucks with 4 speed manual transmission (RPO M20) built within the following VIN break points.
Model
Plant
Year
From
Through
Janesville
1986
GJ522616
GJ525730
St. Louis
1986
GS523447
GS526218
The specific vehicles involved in this campaign have been identified on Vehicle Identification Number Computer Listings. These listings are furnished to
all involved dealers with the campaign bulletin.
DEALER CAMPAIGN RESPONSIBILITY
Dealers are to service all vehicles subject to this campaign at no charge to owners, regardless of mileage, age of vehicle, or ownership, from this time
forward. Whenever a vehicle subject to this campaign is taken into your new or used vehicle inventory, or it is in your dealership for service in
the future, you should take the steps necessary to be sure the the campaign correction has been made before reselling or releasing the vehicle. Owners of
vehicles recently sold from your new vehicle inventory are to be contacted by the dealer and arrangements made to makes the required correction
according to instructions contained in this bulletin. If no owner's name and address were available to GMC Truck at the time of campaign initiation, the
dealer will determine the owner's name and address from the dealership sales records. Please provide this information directly on the second copy of the
listing next to the applicable VIN so that our records may be updated and the appropriate notification mailed to the owner. This second copy should then
be submitted to the address listed below in the previously supplied yellow campaign envelopes.
GMC Truck General Motors Corporation 101 Union Street Plymouth, Michigan 48170
OWNER NOTIFICATION
Owners will be notified of this campaign on their vehicles by GMC Truck (see copy of Owner Letter included with this bulletin). A listing of owner
names and addresses has been furnished to the involved dealers to enable dealers to follow up with owners involved in this campaign. This listing may
contain owner names and addresses obtained from state motor vehicle registration records. The use of such motor vehicle registration data for any other
purpose is a violation of law in several states. Accordingly, you are urged to limit the use of this listing to this campaign.
Service Procedure
Inspection:
^
Disconnect the cable at the negative battery terminal.
^
Raise and support vehicle on a hoist.
^
Remove skid plate if equipped.
^
Drain the transmission.
^
Disconnect the speedometer cable at the transfer case
^
Separate the front propshaft from the transfer case. Move it away from the work area and secure it.
^
Remove the shift lever linkage from the transfer case.
