A/T - 4L60/THM 700R4 200R4 Fluid Filter Seal

TSB 89-28 (SEPT)

SUBJECT:
HYDRA-MATIC
4L60/THM 700-R4
THM 200-4R

SUBJECT: Fluid Filter Seal




A correction to TSB 89-4 (Feb) was issued in the April mailing. This correction gave a new fluid filter seal part number 14018671 (See Figure 1) being supplied by some parts suppliers. This seal was to correct a "cracked filter" condition that could exist when using the filter seal # 8657767 (See Figure 2), as published in our original TSB 89-4 bulletin in February. Hydra-matic Division of General Motors has informed us that part # 14018671 is a speedometer seal, and they do not recommend using It as a filter neck seal. Hydra-matic states, "The correct filter seal is part number 8657767."

They recognize that a problem has been seen in some Hydra-matic 4L60/THM 700-R4 transmissions where the bottom pan "rocks" on the fluid filter. When the pan is bolted down, the filter neck may crack. This is caused in part by variations in the oil pump bore depth and by an increased filter height due to design changes in 1987.

The speedometer seal has been used by some people as a "fix" for the cracked filter condition. The reason this seems to work is that the speedometer seal is more flexible than the filter seal, and allows the filter to tilt off center. This "fix" is not acceptable to Hydra-matic because it does not relieve the condition's root cause, and may jeopardize oil flow through the filter.

If this filter cracking condition is seen in the future, Hydra-matic recommends installing a deeper bottom pan. A 1.0 mm deeper bottom pan became available in 1987 when the auxiliary valve body was added to the 4L60/THM 700-R4. This deeper bottom pan is part number 8663948 - pan and magnet assembly.