3406E Truck Engine Caterpillar

Slave Piston Lash - Adjust

Usage:

Show/hide table

To prevent possible injury, do not use the starter to turn the flywheel.

Hot engine components can cause burns. Allow additional time for the engine to cool before measuring valve clearance.

Show/hide table

This engine uses high voltage to control the fuel injectors.
Disconnect electronic fuel injector enable circuit connector to prevent personal injury.

Do not come in contact with the fuel injector terminals while the engine is running.

Show/hide table

NOTICE

Failure to follow the recommended procedure or the specified tooling that is required for the procedure could result in damage to components. To avoid component damage, follow the recommended procedure using the recommended tools.

The engine valve lash and the injector lash must be within specifications prior to adjusting the compression brake slave piston lash. Refer to Testing and Adjusting, "Engine Valve Lash - Inspect/Adjust" for the correct procedure for inspection of the engine valve lash. Refer to Testing and Adjusting, "Electronic Unit Injector - Adjust" for the proper procedure for inspection of the injector lash adjustment.

Note: The slave piston lash adjustment must be performed while the engine is cold. If the engine is warm, allow the engine to cool prior to performing the following adjustments.

Use the following procedure to adjust the slave piston lash on cylinders 1, 3, and 5:

Put the No. 1 piston at the top center position on the compression stroke. See Testing and Adjusting, "Finding Top Center Position for No. 1 Piston" for further details.

Jake Brake Compression Brake Adjustment

Show/hide table




Illustration 1	g00596577
Typical configuration for Jake Brake engine compression brake (1) Adjustment screw for the slave piston (2) Slave piston (3) Rocker arm

Show/hide table

NOTICE

Prior to adjusting the lash setting for the engine compression brake, check the identification plate that is on the compression brake casting in order to determine the model that is installed on your engine. You must have this model number and the engine serial number prefix in order to determine the lash setting for your engine.

Show/hide table

Table 1
Slave Piston Lash Setting Jake Brake Compression Brakes
Serial Number Prefix and Model Number⁽¹⁾	Horsepower Rating	Slave Piston Lash Setting
2WS1-UP 6NZ1-83125 9NZ1-UP C2A1-Up (Excluding 10R-9846) Jake Brake 340B or Jake Brake 340C	410 hp or less	0.94 ± 0.08 mm (0.037 ± 0.003 inch)
	435 hp or more	0.84 ± 0.08 mm (0.033 ± 0.003 inch)
	375/435 hp Multitorque rating	0.84 ± 0.08 mm (0.033 ± 0.003 inch)
1MM1-UP 7CZ1-03833 5DS1-UP Jake Brake 340B or Jake Brake 340C	All ratings	0.94 ± 0.08 mm (0.037 ± 0.003 inch)
1LW1-33333 Jake Brake 340B or Jake Brake 340C	410 hp or less	0.84 ± 0.08 mm (0.033 ± 0.003 inch)
1LW1-33333 Jake Brake 340B or Jake Brake 340C	435 hp or more	0.68 ± 0.08 mm (0.027 ± 0.003 inch)
5EK1-01820⁽²⁾ Jake Brake 340	435 hp or more	0.68 ± 0.08 mm (0.027 ± 0.003 inch)
4AS1-UpJake Brake 340C	All ratings	0.68 ± 0.08 mm (0.027 ± 0.003 inch)
5EK1-UP⁽²⁾ 6TS1-UP Jake Brake 340A	410 hp or less	0.68 ± 0.08 mm (0.027 ± 0.003 inch)
5EK1-UP⁽²⁾ 6TS1-UP Jake Brake 340A	435 hp or more	0.76 ± 0.08 mm (0.030 ± 0.003 inch)
1LW33334-UP 6NZ83126-UP 9NZ1-UP 7CZ03834-UP Jake Brake 340D	All ratings	0.64 ± 0.08 mm (0.025 ± 0.003 inch)
CJP1-UP MDP1-UP MEP1-UP W1A1-UP Jake Brake 340C	All ratings	1.02 ± 0.08 mm (0.040 ± 0.003 inch)
MBN1-UP C2A1-UP ( 10R-9846 only) Jake Brake 340D	All ratings	0.76 ± 0.08 mm (0.030 ± 0.003 inch)
BXS1-01545 Jake Brake 340C	All ratings	0.89 ± 0.08 mm (0.035 ± 0.003 inch)
BXS01546-UP Jake Brake 340E	All ratings	0.84 ± 0.08 mm (0.033 ± 0.003 inch)

Show/hide table

⁽¹⁾	Check the identification plate that is on the compression brake casting to determine the model that is installed on your engine.
⁽²⁾	Some of the early 3406E Engines 5EK1-01820 were built with either the 340 or the 340A compression brakes.

Note: The slave piston lash settings are specific to the model number of the compression brake and to the serial number prefix of the engine. Use these settings only for the compression brakes and serial number prefixes that are specified in the table.

340D Compression Brakes

Loosen adjustment locknut (1) and back out the adjustment screw until the slave piston is not in contact with the exhaust valve rocker arm.
Insert the appropriate feeler gauge between the foot of the slave piston (2) and the rocker arm (3). Refer to Table 1 for the correct slave piston lash setting.
Turn the adjustment screw for the slave piston in a clockwise direction until the slave piston tightens against the feeler gauge. A slight drag should be felt on the feeler gauge.
Tighten the adjustment locknut (1) to a torque of 34 ± 5 N·m (25 ± 4 lb ft). Recheck the adjustment after you tighten the locknut. If necessary, repeat this procedure.

340, 340A, 340B, 340C, and 340E Compression Brakes

Loosen adjustment locknut (1) and back out the adjustment screw until the slave piston is not in contact with the exhaust valve rocker arm.
Insert the appropriate feeler gauge between the foot of the slave piston (2) and the rocker arm (3). Refer to Table 1 for the correct slave piston lash setting.
Turn the adjustment screw for the slave piston in a clockwise direction until the slave piston tightens against the feeler gauge. Tighten the adjustment screw for one additional turn in the clockwise direction. The valve spring should start to compress. Allow the oil to be purged from the autolash assembly of the compression brake for 30 seconds.
Note: All of the oil must be allowed to drain from the autolash assembly of the compression brake. If the temperature of the oil is below 16 °C (60 °F), allow the oil to be purged for an additional 2 minutes. Serious engine damage may occur if the oil is not properly purged from the autolash assembly.
Slowly turn the adjustment screw counterclockwise until the slave piston begins to loosen against the feeler gauge. A slight drag should be felt on the feeler gauge when the adjustment is correct.
Note: Do not overshoot the setting of the slave piston during adjustment. If you overshoot the setting, this procedure must be repeated.
Tighten the adjustment locknut (1) to a torque of 34 ± 5 N·m (25 ± 4 lb ft). Recheck the adjustment after tightening the locknut. If necessary, repeat the procedure.

Adjust the slave piston lash settings for cylinders 3 and 5 prior to rotating the engine.

After you adjust cylinders 1, 3, and 5, reset the timing pin and turn the flywheel for 360 degrees in the direction of engine rotation. This will position the No. 6 piston at the top center on the compression stroke. Ensure that the timing pin has located the timing hole that is in the flywheel.

Continue to perform the adjustment procedure for the slave piston lash settings on cylinders 2, 4, and 6.

Remove the timing pin from the flywheel after all adjustments have been performed. Reinstall the timing cover.

Pacbrake Compression Brake Adjustment

Show/hide table




Illustration 2	g00975814
Typical configuration for Pacbrake's engine compression brake (1) Adjustment screw for the slave piston (2) Slave piston (3) Rocker arm

Show/hide table

Table 2
Slave Piston Lash Settings Pacbrake Compression Brakes
Serial Number Prefix	Model Designation	Slave Piston Lash Setting
5EK1-Up 6TS1-Up 1LW1-Up 5DS1-Up 2WS1-Up 1MM1-Up 6NZ1-Up 7CZ1-Up 9NZ1-Up	P39A or P39B	0.76 ± 0.08 mm (0.030 ± 0.003 inch)
	P39A or P39B	0.76 ± 0.08 mm (0.030 ± 0.003 inch)
6NZ1-Up 7CZ1-Up 9NZ1-Up	P39C	Product Campaign⁽¹⁾
MBN1-Up	P39D	0.97 ± 0.08 mm (0.038 ± 0.003 inch)

Show/hide table

⁽¹⁾	Contact Pacbrake for information that relates to the product campaign.

Note: The slave piston lash settings are specific to the serial number of the engine. Ensure that the slave piston lash setting that is being used is correct for the serial number of your engine.

P39A Compression Brakes

Loosen adjustment locknut (1) and back out the adjustment screw until the slave piston is not in contact with the exhaust valve rocker arm.
Insert the appropriate feeler gauge between the foot of the slave piston (2) and the rocker arm (3). Refer to Table 2 for the correct slave piston lash settings.
Turn the adjustment screw for the slave piston in a clockwise direction. Tighten the adjustment screw for the slave piston beyond the point of contact with the exhaust valve rocker arm. This will allow the oil to be purged from the slave piston. Once the oil has been purged from the piston, turn the adjustment screw for the slave piston in a counterclockwise direction until the feeler gauge is loose between the adjustment screw and the rocker arm.
Again, turn the adjustment screw for the slave piston in a clockwise direction until a slight drag is felt on the feeler gauge.
Tighten the adjustment locknut (1) to a torque of 34 ± 5 N·m (25 ± 4 lb ft).

Adjust the slave piston lash settings for cylinders 3 and 5 prior to rotating the engine.

P39B, P39D, and P39E Compression Brakes

Loosen adjustment locknut (1) and back out the adjustment screw until the slave piston is not in contact with the exhaust valve rocker arm.
Insert the appropriate feeler gauge between the foot of the slave piston (2) and the rocker arm (3). Refer to Table 2 for the correct slave piston lash settings.
Turn the adjustment screw for the slave piston in a clockwise direction until the slave piston tightens against the feeler gauge. Tighten the adjustment screw for one additional turn in the clockwise direction. The valve spring should start to compress. Allow the oil to be purged from the components of the compression brake for 1 minute.
Slowly turn the adjustment screw counterclockwise until a slight drag is felt on the feeler gauge.
Note: Do not overshoot the setting of the slave piston during this adjustment. If you overshoot the setting, this procedure must be repeat.
While you hold the screw of the adjuster, tighten the adjustment locknut (1) to a torque of 34 ± 5 N·m (25 ± 4 lb ft).
Note: Do not place excessive torque on the locknut that is on the adjustment screw. If excessive torque is placed on the adjustment screw, damage to the components of the compression brake may result.
Recheck the adjustment after tightening the locknut. If a slight drag is not felt on the feeler gauge, repeat the adjustment procedure.