A/T - 440T4 3-2 Downshift Bump/Part Throttle

SIL: 87-5 (Feb)

SUBJECT: 440 T4




Some 1985 THM 440-T4 "BA", "BC", "CM" & "CP" model transaxles (refer to Figure 1), may exhibit a 3-2 downshift bump. This condition may be most prevalent during a part-throttle downshift with the air conditioner operating. A slight transaxle tie-up condition which shakes or rattles the instrument panel during the downshift may also be experienced.

When servicing any 1985 THM 440-T4 "CM" & "CP" model for a 3-2 downshift bump, order and install service package part number 8646951.

Service package part number 8646951 contains one each of the following:

3-2 Control valve spring
1-2 servo boost valve
Instruction sheet

When servicing any 1985 THM 440-T4 "BA" or "BC" model for a 3-2 downshift bump, order and install service package part number 8646953.

Service package part number 8646953 contains one each of the following:

3-2 Control valve spring
Instruction sheet




Refer to Figure 2 of this bulletin and the appropriate Service Information Manual for proper installation procedures. Models "BA", "BC" & "CP" are 1985 models while "CM" is a 1985 1/2 model.

There are differences between the 1985 and 1985 1/2 models which are explained in HYDRA-MATIC PRODUCT SERVICE BULLETIN 85A9.