For 1990-2009 cars

# NO DRIVE, REVERSE, SLIPS/HARSH SHIFT (INSPECT CHECK BALLS)

#### SUBJECT: NO DRIVE OR REVERSE, SLIPS, HARSH 1-2 UP/DOWN SHIFTS, SOFT 2/3 UP/DOWN SHIFTS (INSTALL CORRECT CHECKBALLS)

VEHICLES AFFECTED: 1992 "C, H" MODELS

#### APPLICATIONS:

Oldsmobile 88, 98 and Buick Le Sabre, Park Avenue with Hydra-Matic 4T60-E (M 1 3) transaxles (Models 2CLW and 2YMW).

CONDITION: (FIGURE 1 & 2)

Some C and H Cars equipped with HYDRA-MATIC 4T60-E transaxle (RPO M 1 3) built between Julian Date 021 (January 21) line 3B, to Julian Date 023 (January 23, 1992) line 3A & 3B, may exhibit any or all of the conditions listed below (symptom will depend on checkball function and degree of severity).

o No drive/reverse or slips in drive/reverse range.

o No converter clutch apply or straw colored 'HOT' converter housing assembly.

o Harsh 1-2 upshift/downshift feel.

o Soft 2-3 upshift feel and/or no/slipping 3rd gear.

o No D1, (manual low) range.

The transaxles were identified as being used in vehicles assembled at the Orion and Buick City vehicle assembly plants. The assembly plant locations can be determined by the 1 1 th position on the vehicle VIN system. An Orion assembled vehicle will have a number '4' in the 1 1 th position of the VIN system while a Buick City assembled vehicle will have the letter "H."

Suspect transaxles can be identified by the information on the nameplate (Figure 1) and VIN system (Figure 2). Both nameplate and VIN system information must be present to consider the vehicle a suspect for this condition.

CAUSE: (FIGURE 3 & 4)

The transaxles built with the above-mentioned criteria may have had smaller checkballs installed in the four (4) checkball locations of the channel plate assembly (401). The desired checkballs should be between 6.40mm (0.252") maximum and 6.29mm (0.247") minimum diameter. Due to the minimal size difference between a larger and a small checkball, R is essential that the check-balls be verified using a micrometer. A small checkball may cause premature wear of the spacer plate and/or stick in the check-ball pockets of the channel plate assembly.

Incorrect Checkballs in Channel Plate

o No/slips in drive and reverse range

o Harsh 1-2 upshift or downshift

o Soft 2-3 upshift and/or no/slipping in 3rd gear

o No (D1) manual low range

#### NOTE: Some spacer plate peening is considered acceptable and preferred because it can help set the checkball. The following two procedures can help determine if the spacer plate can be reused. Perform the following at all checkball locations.

1. The spacer plate must be inspected 1 00 percent for raised material on the opposite side of the checkball seat (see Figure 5). If the material on the opposite side is raised, the peening is too severe and spacer plate must be replaced.

2. To verify that the spacer plate is peening evenly and the ball is sealing correctly, seat the checkball on the spacer plate. Shine a beam of light on the opposite side and inspect for light between the spacer plate and checkball (see Figure 6). No trace of light should be present. If light can be seen, a proper seal does not exist, and the spacer plate needs to be replaced.

#### CORRECTION:

Begin with the "Quick Check Procedure' ("Automatic Transaxle Diagnosis" section of the 1992 Service Manual) which provides a general outline of how to diagnosis a HYDRA-MATIC 4T60-E transaxle. This procedures will aid the Technician in choosing the proper path to diagnose the transaxle by describing the basic checks and then referencing the locations of the specific checks. This will ensure the vehicle has been properly diagnosed and no unnecessary repairs are performed.

SERVICE PARTS INFORMATION:

Service Parts were set up so only damaged components need be ordered and replaced.

Part Number Description Model Usage

8644902 Pkg. Side Cover Gaskets 2CLW, 2YMW

8651922 Pkg. Spacer Plate Gaskets 2CLW, 2YMW

0104918 Pkg. Checkball - .25' diameter 2CLW, 2YMW (contains 5 checkballs .25' diameter per package. Two (2) packages will need to be ordered to replace all (9) checkball)

8680495 Plate Asm. Valve Body Spacer 2CLW and 2YMW

8681846 Channel Plate Asm. Complete 2CLW

8681847 Channel Plate Asm. Complete 2YMW

Incorrect Checkballs in Channel Plate

o No/slips in drive and reverse range

o Harsh 1-2 upshifts or downshifts

o Soft 2-3 upshift and/or no/slipping in 3rd gear

o No (D1) manual low range

#### NOTE: Due to the minimal size difference between a "larger" and a "small" checkball, it is recommended that if the check-balls need replacing, all (9) nine sized checkballs be discarded and replaced with checkballs (.25' diameter) in service package #01 04918. It should also be noted that since checkball #6 was not suspect in this bulletin, it must be saved and reused.

For vehicles repaired under warranty use 1992 Labour Time Guide:

Labour Operation: K-6540, "Valve Body and Oil Pump Assembly R and R or Replace," K-7461, "Channel Plate and/or Gasket-Replace,"

SERVICE MANUAL REFERENCE:

Refer to the 1992 Service Manual, Automatic Transaxle On-Vehicle Service Section 7A for proper On-Vehicle Service to remove and replace a control valve body. Refer to the HYDRA-MATIC Automatic Transaxle Unit Repair Section for proper checkball locations and functions.

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.