A/T - New Third Clutch Sprag Assembly & Input Carrier
NO.: 93-I-45DATE: June, 1993
GROUP: 7
CORP. NO.: 377121
SUBJECT:
INFORMATION ON NEW THIRD CLUTCH SPRAG ASSEMBLY AND MODIFIED INPUT CARRIER FOR 1993 DE VILLES, FLEETWOODS, ELDORADOS, AND SEVILLES
Third Clutch Sprag:
A new design input and third clutch sprag assembly has been implemented into production in all 1993 4T60-E (RPO N413) transaxles.
Date of Production-Change (Figure 1):
Effective February 1, 1993 (Julian Date 032) all 4T60-E (RPO ME9) transaxles were built with a new dual sprag assembly in place of the prior third roller clutch and input sprag assembly. The 4T60-E Service Replacement Transmission Assembly (SRTA) will phase the dual sprag assembly into units beginning May 1, 1993. Future 4T60 SRTA transaxles for past model service will also contain the dual sprag assembly but at a later, unspecified date.
Service Action (Figure 2):
There are many differences between the prior third roller clutch and input sprag assembly and the new dual sprag assembly. Therefore, transaxles built prior to February 1, 1993 must be serviced differently than transaxles built on or after February 1, 1993.
To accommodate the new dual sprag assembly it was necessary to modify and/or change the following components:
^ Input sprag assembly (654/665)
^ Retainer input sprag clutch (655/666)
^ Input sun gear spacer (657/667)
^ Input sun Scar (658/668)
^ Input carrier assembly (662/672)
IMPORTANT:
None of the new modified components listed above (used in the new dual sprag assembly) are interchangeable with the prior third roller clutch and input sprag assembly. Failure to comply may result in assembly concerns and/or severe transaxle damage.
NOTE:
The new dual sprag assembly can on be serviced back to 1989 transaxles (units with 10 plate third clutch packs). (All 1989 to current model 4T60/4T60-E transaxles have ten-plate third clutch packs.) Units built prior to 1989 use an eight-plate third clutch pack and have significant dimensional differences in key components.
See Hydra-Matic Bulletin 897440-001 (Corporate reference number 877140) for additional information on part changes between 1988 and 1989 to current model transaxles.
NOTE:
In some cases, it may be cost effective to consider a Service Replacement Transmission Assembly (SRTA) instead of a transaxle repair.
Input Carrier (Figure 3):
Along with the new dual sprag assembly, a new designed input carrier (662/672) gear set was also implemented. The following components were modified in the input carrier:
^ Larger contoured needle bearings
^ Larger pinion shafts
^ Additional carrier lube grooves
^ Top hub and bushing eliminated (660/670)
(The service part information is for units built on February 1, 1993 to current.)
Parts are currently available from GMSPO.
Labor time should be charged under Operation K7533 for "Third Roller or Sprag Input Clutch (with race)" at 6.8 hours for DeVilles and 8.0 hours for Eldorados and Sevilles.
Refer to the appropriate Service Information Manual for the proper removal and installation procedures.