CAMPAIGN:SOFT CRANKSHAFT SPROCKETS (NO HEAT - TREAT)
SUBJECT: SOFT CRANKSHAFT SPROCKETS (NO HEAT-TREAT)
MODELS: 1993 C/K, G, P TRUCKS WITH 7.4L ENGINES (VIN CODE N)
THIS BULLETIN CANCELS AND REPLACES 93-C-11 ISSUED JUNE 1993. DESTROY ALL COPIES OF 93-C-11.
REVISIONS INCLUDE AN ADDED STEP TO THE SERVICE PROCEDURE AND CHANGES IN THE WARRANTY INFORMATION.
General Motors has determined that CERTAIN 1993 C/K, G, and P trucks with the 7.4L gas engines may have been built with soft crankshaft sprockets. A non-hardened sprocket will have excessive wear and could cause an engine failure.
To prevent this failure from occurring, dealers are to replace the crankshaft sprocket. In the event that the truck is towed in and it is determined that the crankshaft sprocket has failed, the engine should be replaced. To replace the engine, call your Technical Assistance Department for a new engine replacement. DO NOT order engine from General Motors Service Parts Operation (GMSPO).
VEHICLES INVOLVED
Involved are CERTAIN 1993 C/K, G, P trucks equipped with option (L19) 7.4L TBI gas engine and built within the following VIN breakpoints:
Year Model Plant From Through
1993 C E PE502218 PE510574 J PJ500613 PJ708196 1 P1504168 P1517580 K E PE502197 PE519555 J PJ700071 PJ704234 1 P1504267 P1508729 G 4 P4501039 P4503018 P 3 P3500229 P3500320
The specific vehicles involved in this campaign have been identified by Vehicle Identification Number Computer Listings. These listings are furnished to all involved dealers with the campaign bulletin.
Dealers should confirm vehicle eligibility through VISS (Vehicle Information Service System) prior to beginning campaign repairs.
These listings 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 the follow-up necessary to complete this campaign. Any dealer not receiving a computer listing with the campaign bulletin has no involved vehicles currently assigned.
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. Dealers are to correct all affected vehicles in new and used vehicle stock prior to their sale.
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 ensure 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 make the required correction according to instructions contained in this bulletin.
If the name and address of the owner of an involved vehicle was unavailable to GMC Truck Division at the time of campaign initiation, the dealer must 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 Division General Motors Corporation 101 Union Street Plymouth, Michigan 48170
OWNER NOTIFICATION
Owners will be notified of this campaign on their vehicles by GMC Truck Division (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
1. Remove torsional damper and front cover per the 1993 Service Manual, section 6A5 using tool J 39046.
NOTICE: Extreme care should be used when removing front cover from engine block to prevent damage to oil pan gasket. Oil pan gasket is attached to front cover at RTV joints.
2. Remove crankshaft sprocket using tool J 28509-A. See section 6A5 in the Service Manual.
3. Inspect crankshaft sprocket for excessive wear. Place new crankshaft sprocket and crankshaft sprocket removed from truck on a flat surface on edge (see illustration #1). If old gear is 1/8 (0.125) inch smaller, go to step #4. If old gear is the same or less than 1/8 (0.125) inch smaller, go to step #5.
4. Install new crankshaft sprocket using tool J 22102, camshaft sprocket and timing chain, and magnetic oil drain plug.
5. Only install new crankshaft sprocket using tool J 22102.
6. Install front cover and torque bolts to 10 N-m (96 lbs. in.). Install torsional damper and torque bolt to 115 N-m (85 lbs. ft.).
7. Change oil and filter.
8. Only return the crankshaft sprocket to:
G.M. Powertrain 30003 Van Dyke Warren, MI 48090 Room 2-207
NOTICE: All crankshaft sprockets are to be wire tagged with complete VIN #, mileage, and date.
9. Install "Campaign Identification Label".
PARTS INFORMATION
Parts are to be obtained from General Motors Service Parts Operation (GMSPO). To ensure that these parts will be obtained as soon as possible, they should be ordered from GMSPO on a C.I.O. order with no special instruction code but order under an advise code (2).
Part Description Quantity Number ------------------------------------------------------- 03902426 Crankshaft Sprocket 1 10114161 Front Cover Gasket 1 14103224 Timing Chain 1 (if required) 00330814 Camshaft Sprocket 1 (if required) 25013977 Oil Filter (PF1218) 1 12345616 Oil, 10W-30 5 qts. 23011420 Magnetic Drain Plug 1 (if required) 13860039 Water Pump Gasket 2
NOTICE: Due to the limited number of involved vehicles, parts should be ordered based on involved vehicle listings.
WARRANTY INFORMATION
Dealers should submit a warranty claim on each vehicle completed under this campaign.
Labor *Time Trouble Parts ***Net Operation Description Allowance Code Allowance Amt Number ----------------------------------------------------------------------------- V8090 Replace Crankshaft Sprocket, C/K 2.6 96 ** $#.## Oil and Filter G 2.9 P 3.5 V8093 Replace Crankshaft Sprocket, C/K 2.6 96 ** $#.## Cam/Shaft Sprocket, Timing Chain, G 2.9 Oil Pan Plug, Oil & Filter P 3.5
V8096 Replace Engine C/K 6.1 96 -- -- G 8.3 P 7.8
*For dealer to receive Administrative Time Allowance associated with this campaign, add 0.1 hour to the Labor Operation Time Allowance.
**The "Parts Allowance" should be the sum total of the current GMSPO Dealer net price plus 30% of all parts required for the repair.
***The $ #.## shown in the "net amount" column represents UPS shipment charges required for returning replaced crankshaft sprockets. Add 0.2 hours to the Labor Operation Time Allowance for parts handling.
NOTE: CONTACT YOUR GMC DISTRICT SERVICE MANAGER IF YOU HAVE ANY ADDITIONAL QUESTIONS.
CAMPAIGN IDENTIFICATION LABEL
Each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin will require a "Campaign Identification Label." Each label provides a space to include the campaign number and five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or ball point pen.
Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in for periodic servicing by the owner.
Apply "Campaign Identification Label" only on a clean, dry surface.
ADMINISTRATIVE PROCEDURE
Procedures covering this campaign are outlined in Section V of your dealership's "GMC Truck Warranty Claims Processing Manual" #P9119.
Dear GMC Truck Owner:
As a valued customer, your complete satisfaction with your GMC truck is our goal. In keeping with this goal, we want to let you know that we have discovered a problem that could affect your vehicle and we want to take care of it at no charge to you.
On certain 1993 C/K models, G vans, and P trucks with the 7.4L gas engines, such as yours, the engine crankshaft sprocket may not have been properly hardened. This condition could resuit in excessive sprocket wear and may cause an engine failure.
To be absolutely sure that your vehicle is to specifications, whether it has the problem or not, we will install a new crankshaft sprocket and change the engine oil and oil filter free of charge. Instructions for performing this service have been sent to your GMC dealer, and parts are available. Please contact your GMC dealer to arrange a service date as soon as possible. This procedure will take about three hours to complete, but you should ask how much additional time your dealer will need to schedule and process your vehicle.
The enclosed postage paid owner reply card identifies your vehicle. Presentation of this card to your dealer will assist in making the necessary correction to your vehicle in the shortest possible time. If you have sold or traded your vehicle, please furnish us the complete name and address of the person you sold or traded your vehicle to and return the card to us.
We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our product.
GMC TRUCK DIVISION GENERAL MOTORS CORPORATION
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.
