CAMPAIGN: CLUTCH FORK IMPROPERLY MACHINED
SUBJECT: CLUTCH FORK IMPROPERLY MACHINED
MODELS: 1990 C5H, C6H, C7H TOPKICK/KODIAK TRUCKS EQUIPPED WITH 427 GAS (LRO) 3116 CAT DIESEL ENGINES (LXO), EATON/FULLER FS4005B, FS4005C, FS5005A, FS5005C OR FS5106 TRANSMISSIONS (RPO'S MSC, MSA, MPU, MPV OR MMO) AND 1.5 INCH SPLINE (RPO MWX)
General Motors has determined that on certain 1990 TopKick/Kodiak trucks equipped with certain Eaton/Fuller transmissions, the clutch fork tangs were improperly coined, resulting in a fork that binds in the throw out bearing groove when the fork tang rotates during clutch operation. This binding can eventually result in a cracked or broken release bearing carrier. There may be no noticeable deficiency in clutch operation even though this condition exists.
To correct this condition, dealers will replace the clutch fork and throw out bearing assembly.
VEHICLES INVOLVED
Involved are certain 1990 TopKick/Kodiak trucks equipped with 427 gas (LRO) or 3116 CAT diesel engines (LXO), Eaton/Fuller FS4005B, FS4005C, FS5005A, FS5005C or FS5106 transmissions (RPO's MSC, MSA, MPU, MPV or MMO) and 1.5 inch spline (RPO MWX) and built within the following VIN breakpoints:
Model Year Model From Through ---------- ------- -------- --------- 1990 GMC LJ600001 LJ608446 Chevrolet LJ200007 LJ203326
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.
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 cor- rection 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 REMOVAL AND REPLACEMENT
(Refer to Sections 7B-Manual Transmissions and 7C-Clutch in the 1990 Medium Truck C5H, C6H and C7H Models Service Manual, X-9033)
1. Disconnect the negative battery connections.
2. Block the wheels to prevent vehicle movement. CAUTION: Support the engine with a suitable hoist or lack to prevent engine from tipping prior to transmission removal.
3. Place the transmission in Neutral.
4. Disconnect propeller shaft and hanger and lay aside.
5. Disconnect power take-off (PTO) and controls, if equipped.
6. Disconnect transmission mounted park brake cable, if equipped.
7. Disconnect fuel transfer bar and lines if vehicle equipped with dual fuel tanks and diesel engine.
8. Disconnect electrical connections (speed sensor, backup light/alarm switch and/or temperature switch if equipped).
9. Disconnect the transmission shifter from stub.
10. Disconnect return spring, clutch cable and transmission mounted support bracket.
11. Install transmission jack and support transmission for removal. Fasten a safety chain over the top of the transmission and to both sides of the jack. (Since transmission fluid was not previously drained, DO NOT tip transmission.)
12. Remove clutch housing to flywheel housing bolts.
13. Remove the transmission assembly from the vehicle.
14. Remove clutch release fork and release bearing and discard.
15. Apply a light coat of high temperature grease to the main shaft drive gear bearing retainer and splined portion of the transmission main drive gear shaft. NOTE: Do not apply too much grease. Under normal operation excess grease can be thrown onto clutch facings resulting in damage to the clutch.
16. Install new clutch release fork assembly (P/N 15574633) and new release bearing (P/N 15556905).
17. Reinstall transmission assembly. Shift the transmission into high. Rotate the transmission output flange or yoke to align the transmission main drive gear shaft with the clutch disc hub. Move the transmission forward, guiding the main drive gear shaft into the clutch disc splines. Avoid springing the clutch when the transmission is being installed. DO NOT let the transmission drop or hang unsupported in the splined hub of the clutch disc. NOTE: When instaffing the transmission, do NOT allow the weight of the transmission to hang on the clutch disc hub. The clutch disc will become distorted, and adversely affecting the clutch operation.
18. Reinstall clutch housing to flywheel housing bolts.
GAS ENGINES:
Equipped with SAE Number 2 type bell housing torque clutch housing to flywheel housing bolts to 58 Nm (43 Ft. Lbs.).
DIESEL ENGINES:
Equipped with SAE Number 2 type bell housing torque clutch housing to flywheel housing bolts to 55 Nm (41 Ft. Lbs.).
19. Remove the transmission jack.
20. Reconnect clutch cable, transmission mounted support bracket and return spring.
21. Adjust clutch pedal free-travel. Proper free travel is between 25mm and 51mm (1 to 2 inches).
22. Reinstall transmission shifter to stub and place transmission in Neutral.
23. Reconnect electrical connections.
24. Reconnect transmission mounted park brake cable (if equipped) and adjust.
25. Reconnect the PTO, if equipped.
26. Reconnect dual fuel tank cross bar and lines, if equipped.
27. Reconnect propeller shaft and hanger.
28. Unblock the wheels.
29. Reconnect negative battery connection.
30. Install "Campaign Identification Label".
31. Test drive vehicle.
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 Number Description Quantity -------- ------------------- -------- 15574633 Clutch Fork Assembly 1 15556905 Release Bearing 1
WARRANTY INFORMATION
Dealers should submit a warranty claim on each vehicle completed under this campaign.
Labor Operation *Time Trouble Number Description Allowance Code -------- -------------- --------- ----- V6310 R & R 1.5Hrs 96 Transmission
Add:
Disconnect & Connect PTO .3 Hr.
Diesel w/Dual Fuel Tanks .5 Hr.
w/Trans. Mounted Parking Brake .6 Hr.
*For dealer to receive Administrative Time Allowance associated with this campaign, add 0.1 hour to the Labor Operation Time Allowance.
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 infor- mation 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 "GM Truck Claims Processing Manual" #P8919.
Dear GM Truck Owner:
Our records show that you own one of our new 1990 model General Motors Top- Kick/Kodiak medium trucks. The rate at which these trucks have been accepted into the stream of commerce has been very gratifying to us. In addition, feedback from customers, dealers and our own tracking systems indicate a very high degree of product reliability thus far.
We have recently become aware of a situation on certain 1990 TopKick/Kodiaks with specific Eaton/Fuller transmissions that may eventually reduce your truck's reliability. The clutch fork tangs on your truck were improperly coined and may result in a cracked or broken clutch release bearing carrier or binding in the clutch linkage during clutch operation. Field research indicates most customers are unaware there is even any deficiency. You should also be aware that it is very unlikely this situation will cause you any unscheduled maintenance.
In the interest of maintaining your truck's reliability, we would like to correct this condition by replacing the clutch fork and release bearing assembly at no charge to you.
At your convenience, please contact your GM Truck dealer to arrange a service date. Instructions for making this correction have been sent to your dealer. Please ask your dealer if you wish to know how much time will be needed to schedule, process and repair 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 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.
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.
