Transmissions Equipped With Electronic Clutch Pressure Controls (ECPC) Caterpillar

Transmissions Equipped With Electronic Clutch Pressure Controls (ECPC)

Usage:

TRACK-TYPE TRACTORS

WHEEL LOADERS

INTEGRATED TOOLCARRIERS

D5M (6GN, 5ES, 3CR, 6AS),
D6M (3WN, 4HS, 6LR, 4JN, 5NR),
D6R (2YN, 2HM, 6FR, 9ZS, 8LN, 9MN, 4HN, 7AR, 6JN, 8XN, 6HR, 4MN, 4JR, 4WR, 6MR, 3ZN, 4FM, 5PR, 1RW, 9PN, 8TM, 4TR, 7KN, 7DR, 5LN, 9BM, 5RR, 7GR, 7CR),
D7R (2HR, 3ZR, 9HM, 4SR, 2EN, 5MR, 3DN, 6ER) TRACK-TYPE TRACTORS;
950G (2JS, 3JW, 4BS, 5FW),
962G (7BW, 3BS, 4PW) WHEEL LOADERS;
IT62G (6PS) INTEGRATED TOOLCARRIERS

Problem:

There have been a few instances when the transmission on a machine equipped with Electronic Clutch Pressure Controls (ECPC) has "locked up". This can occur when an orifice plug in the modulating valve group comes loose and backs out. If the plug backs out, oil will flow uncontrolled through the valve and cause the valve to shift, continuously pressurizing the corresponding clutch.

When this occurs the transmission will not engage any gear except for the gear in which the affected clutch has pressurized. For example, if the plug becomes loose in the valve controlling the reverse clutch, the transmission will not engage forward speeds, while it will operate in all reverse speeds. If the plug becomes loose in the valve controlling the clutch for 2nd speed, the transmission will operate normally in 2nd forward and reverse, but will not engage all other speeds in both forward and reverse.

Solution:

The problem can be confirmed by removing the cartridge assembly from the modulating valve and inspecting the end of the spool assembly. When properly installed, the orifice plug will be flush with, or below, the end of the spool assembly. Do NOT use a wrench to confirm whether the orifice is loose. The torque on this orifice plug is 2 N·m (18 lb in). Exceeding this torque will damage the edge filter which is installed below the orifice plug in the spool assembly. At this time, our recommendation is to replace the modulating valve group if the orifice is loose.

This problem is believed to be confined to a short production period. If this problem is encountered in the field dealers are urged to report the date code which is stamped on the cartridge assembly under the coil. The date code is a four character numeric corresponding to the year and week of year of manufacture. For example, 9742 means the valve was manufactured on the 42nd week of 1997.

To ensure consistency when reporting, use substitute group number 3167 in the group number field and use the group number to complete the part number field.