A/T - New Drive Link Assembly and Drive/Driven Sprockets
FILE IN SECTION: 7 - TransmissionBULLETIN NO.: 37-71-07A
DATE: December, 1994
SUBJECT:
New Drive Link Assembly and Drive/Driven Sprockets
MODELS:
1993 Buick Riviera
1993-94 Buick Century, Park Avenue, LeSabre, Regal
1994 Buick Skylark
1993 Cadillac Sixty Special, Fleetwood (FWD), Eldorado, Seville
1993-94 Cadillac DeVille
1993-94 Chevrolet Lumina, Lumina APV
1994 Chevrolet Beretta, Corsica
1993-94 Oldsmobile Cutlass Ciera, Ninety Eight, Eighty Eight, Cutlass Supreme, Silhouette
1994 Oldsmobile Achieva
1993-94 Pontiac Bonneville, Grand Prix, Trans Sport
1994 Pontiac Grand Am
TRANSAXLE APPLICATIONS:
Hydra-Matic 4T60 (RPO ME9)
Hydra-Matic 4T60-E (RPO M13)
TRANSAXLE MODELS:
1993 4T60 Models
1993-94 4T60-E Models
This bulletin is being revised to change incorrect part numbers in Service Parts Information section. Please discard bulletin number 377107
(Group Reference 7 - Transmission).
A new Drive Link Assembly and Drive/Driven Sprockets were implemented into production on some 1993 Hydra-Matic 4T6O (RPO ME9) and some 1993-94 Hydra-Matic 4T60-E (RPO M13) transaxies. The new Drive Link Assembly is a Rocker Joint design. It reduces drive link stretch and wear and improves fuel economy at highway speeds. The Drive/Driven Sprockets were changed to accommodate the new Drive Link Assembly.
The new Rocker Joint Drive Link design was initially implemented in production in late calendar year 1992, but production switched back to the previous Round Pin Drive Link design in calendar year 1993.
The Rocker Joint Drive Link design was again implemented in production in early calendar year 1994. Julian dates are not available to identify which Drive Link design is in the transaxle. Visual inspection is necessary to determine Drive Link type.
SERVICE INFORMATION
When servicing the Drive Link Assembly or Drive/Driven Sprockets on a 4T6O or 4T60-E transaxle, install the same design service replacement part as the original. To identify the Drive - Link design, inspect for the following:
Round Pin Design (1st design)
^ Drive Link Assembly has a BLACK/DARK master link.
^ Drive/Driven Sprockets have a BLUE dye marking.
Rocker Joint Design (2nd design)
^ Drive Link Assembly has a COPPER/BRIGHT master link.
^ Drive/Driven Sprockets have a RED dye marking.
The new Rocker Joint Drive Link Assembly CANNOT replace the Round Pin Drive Link Assembly on a transaxle unless the Drive/Driven Sprockets are replaced with the new design. Likewise, the Round Pin Drive Link Assembly CANNOT replace a Rocker Joint Drive Link Assembly unless the Drive/Driven Sprockets are replaced with the previous design. A Rocker Joint Drive Link will not fit on a Round Pin Sprocket. A Round Pin Drive Link will appear loose or "stretched" on a Rocker Joint Sprocket and will result in a noise/durability condition.
Only use the "Drive Link Inspection" procedure listed in the 4T60-E Unit Repair Section of the 1993 and 1994 Service Manuals when checking Round Pin Drive Links for wear. A "good" Rocker Joint Drive Link may not check as acceptable using the 1993/1994 Service Manual. Use the following procedure to check Rocker Joint Drive Links for wear:
1. Make sure Driven Sprocket Support and both sprockets are fully seated into case.
2. Pull Drive Link toward case at location of arrows in Figure 3.
3. Measure gap between Drive Link and case feature with a straight edge rule.
4. If measurement is 3.2 mm (1/8 in) or greater, Drive Link can be reused. If measurement is less than 3.2 mm (1/8 in), replace Drive Link.
This revised "Drive Link Inspection" procedure will be included in 1995 Service Manuals.
PARTS INFORMATION
Parts are currently available from GMSPO.
WARRANTY INFORMATION
For vehicles repaired under warranty, use:
Labor Operation: K-7520 for "Link Assembly, Transaxle Drive Replace"
Inc: Cooler line flush, oil pressure test, clean and inspect parts and all necessary measurements and adjustments.
Note:
For check and adjust toe-in, refer to operation E2000 and add the applicable times to the regular hours column. Applies to W series only.