SERVICE GUILD: 125C AND 440-T4 TRANSAXLE FINAL DRIVE RATIO

TRANSMISSION MODELS: VEHICLE APPLICATIONS: ALL 1980-89 A,C,H,E,N,H,W,X

Bulletin Covers:

When identifying a 125C/Hydra-Matic 3T40 or 440-T4/Hydra-Matic 4T60 transaxle for the purpose of ordering parts, there may be conflicting final drive ratios listed in different publications for the same transaxle I.D. code.

Some sources, such as the Chassis Service Manual, may list the actual ratio of the final drive in the transaxle. Other sources, such as the CANSPO Parts catalogue may list an "AXLE RATIO" which is figured using ratio of the final drive assembly combined with the drive to driven sprocket ratio of the drive chain.

The chart below lists the drive/driven sprocket ratio, final drive ratio, and overall final drive ratio of the transaxle models most commonly used in 1989 Oldsmobile vehicles.

1989 125C/Hydra-Matic 3T40 --------------------------- Tooth Ratio Final Trans Drive/Driven Drive Axle Code Sprocket Ratio Ratio ---- -------- ----- ----- 9BBC 38/32 2.84 2.39 9BUC 38/32 2.84 2.39 9CTC 35/35 2.84 2.84 9KCC 35/35 3.06 3.06 9KDC 35/35 3.33 3.33 9PDC 35/35 2.84 2.84 9PNC 35/35 2.84 2.84

Tooth Ratio Final Trans Drive/Driven Drive Axle Code Sprocket Ratio Ratio ---- -------- ----- ----- 9RUC 35/35 2.84 2.84 9BAH 37/33 3.06 2.73 9BDH 37/33 3.06 2.73 9BFH 35/35 3.06 3.06 9BHH 35/35 2.84 2.84 9BJH 37/33 3.33 2.97 9BPH 35/35 2.84 2.84 9BWH 37/33 3.33 2.97 9CDH 35/35 3.33 3.33 9CLH 35/35 3.33 3.33 9CPH 35/35 3.33 3.33 9CYH 35/35 3.33 3.33 9CZH 35/35 3.33 3.33

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.