CAMPAIGN: ENG./TRANS. MISMATCH (REBUILD TRANSMISSION)

Subject: PRODUCT CAMPAIGN 86C03 ENGINE TRANSMISSION MISMATCH

Model and Year: 1985 & 1986 CHEVROLET C70 MEDIUM DUTY KODIAK TRUCKS EQUIPPED WITH RPO ME3 (MT 643 MODEL DETROIT DIESEL ALLISON TRANSMISSION) AND RPO LQC (3208T MODEL CATERPILLAR ENGINE)

General Motors has become aware of a condition where certain 1985 & 1986 model C70 Medium Duty Kodiak trucks were assembled with an improperly matched engine/transmission combination. An Allison Model MT 643 transmission governed at 2,600 RPM was improperly mated to a Caterpillar Model 3208T engine governed at 2,200 RPM. This mismatch results in the transmission not shifting into 4th gear when the engine is at full throttle; poor vehicle acceleration capability; and the torque converter slipping excessively resulting in higher than normal transmission oil temperatures which will shorten transmission life.

To prevent the possibility of this condition occurring, it will be necessary to rebuild the transmission torque converter and valve body to shift at 2,200 RPM on all involved vehicles.

VEHICLES INVOLVED

Involved are certain 1985 & 1986 Chevrolet C70 Medium Duty Kodiak model trucks equipped with a Detroit Diesel Allison MT 643 automatic transmission (RPO ME3) and a Caterpillar 3208T engine (RPO LQC). The only vehicles involved are listed below:

FV210112 GV100619 FV210381 GV100873 FV211456 GV102585 FV211555 GV102615 FV218652 GV102617

Involved vehicles have been identified by Vehicle Identification Number Computer Listings. Computer listings contain the complete Vehicle Identification Number, owner name and address data, and are furnished to the involved dealers with the campaign bulletin. Owner name and address data furnished will enable dealers to follow-up with owners involved in this campaign.

These listings may contain owner names and addresses obtained from State Motor Vehicle Registration Records. The use of such motor vehicle regis- tration 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 was not shipped any involved vehicles.

OWNER NOTIFICATION

Owners will be notified of this campaign on their vehicles by Chevrolet Motor Division (see copy of Owner Letter included with this 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 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 modification according to instructions contained in this bulletin.

SERVICE INFORMATION

Follow the chart to determine your involvement.

Status Correction

Dealer does not have DDAD Vehicle can be taken to a DDAD distri- Allison Transmission Agreement. butor for repair, or transmission can be removed from vehicle and taken to an authorized DDAD distributor to have valve body and converter rebuilt to specifications.

Dealer has Maintenance Service Vehicle can be taken to a DDAD distri- Operations, designated butor for repair, or transmission can responsibility for the MT 643. be removed from vehicle and sent to a DDAD distributor. If elected, after the transmission is removed by dealer, remove valve body and converter to be sent to a DDAD distributor for repair and calibration.

Dealer is Overhaul Service Campaign can be completed at dealership. Operation, designated Valve body must be calibration tested responsi ility for the by DDAD distributor. MT 643.

SERVICE PROCEDURE

Follow the instructions as outlined in the Service Information section of this bulletin. If the transmission is to be repaired at a Chevrolet dealer- ship with a DDAD Transmission agreement, refer to the Allison Transmission Service Manual SA 1317J for the following modification procedures.

Service Manual Operation Section -------------------- --------------- R & R Transmission 4-7

R & R Trans. Oil Pan 5-4

Valve Body Overhaul/Shift 5-5, 6-4 Spring Replacement/Modulator

Converter R & R and 5-4, 6-3 Overhaul, Replace Stator

Valve Body, Test 3-10

PARTS INFORMATION

Parts are to be obtained from the DDAD distributor in the dealer's area of responsibility.

Following is an add/delete list which is to be followed to convert the supplied transmission part number 23014313 to the proper assembly part number 23040278.

Quantities other than one each are noted.

Quantity Add Part Name Delete --------- -------- ---------------- ------------ 2 23016564 Converter Seals 6758036 Seal Ring 24 190139 Converter Nuts 6837540 Hold Spring 6837541 23011980 1-2 Shift Spring 23017044 23017028 2-3 Shift Spring 23013272 23013407 3-4 Mod. Sleeve

3-4 Mod. Valve 6881033 23013406 3-4 Mod. Valve 23017047 3-4 Shift Spring 23013271 6880045 Ist Trim Outer Spring 23012937 6885047 2nd Trim Outer Spring 6837692 23013908 2nd Trim Inner Spring 6885166 23018733 4th Trim Outer Spring 6880045 6880118 4th Trim Inner Spring 6885166 23016355 Mod. Lockup Spring 23017029 3rd Trim Inner Spring 6885166 23015077 Separator Plate Kit* 23019543 6881434 Stator Assembly 6836585 23016682 Filter and Gasket Kit 23019201 23013996 Modulator Body 23015348 23013997 Modulator Valve 23013764

*Follow instruction sheet in kit to drill separator plate. Use configuration specified for P/N 23013812 with adjustable lock up torque converter.

CLAIM INFORMATION

Submit a Product Campaign Claim with the information indicated below:

| |LABOR|LABOR| OTHER| NET REPAIR PERFORMED |FC| OP | HRS | HRS | AMOUNT ----------------------------------|--|-----|-----|------|-------- DELIVER TRUCK TO DDAD DISTRIBUTOR | | | | | FOR CAMPAIGN REPAIR |00|V3270| 1.0 | .1 | ----------------------------------| |-----|-----|------|-------- R&R TRANSMISSION & DELIVER | | | | | TRANSMISSION TO DDAD DISTRIBUTOR | | | | | FOR CAMPAIGN REPAIR |00|V3271| 8.2 | .1 | ----------------------------------| |-----|-----|------|-------- R&R TRANSMISSION, R&R VALVE | | | | | BODY & CONVERTER FROM TRANSMISSION| | | | | & DELIVER THESE COMPONENTS TO DDAD| | | | | DISTRIBUTOR FOR CAMPAIGN REPAIR |00|V3273| 9.8 | .1 | ----------------------------------| |-----|-----|------|-------- R & R TRANSMISSION & MODIFY | | | | | ACCORDING TO INSTRUCTIONS IN | | | | | BULLETIN |00|V3272| 11.7| .1 |

*Campaign Administrative Allowance.

**The Net Amount Column should be used to indicate the total amount of the sublet charges (DDAD repair) for the work performed.

Dealers will automatically receive the correct labor allowance for their involvement in this campaign based on the labor operation performed.

CAMPAIGN IDENTIFICATION LABEL

Each vehicle modified 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 five digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or ballpoint 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" onlv on a clean dry surface.

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.