Caterpillar Recommends an Inspection of the Timing Chain Tensioner on Certain Mini Hydraulic Excavators Every 1000 Hours {1241} Caterpillar

Excavator

307B (S/N: AFB1-UP)

307C (S/N: BNE1-UP; BCM1-UP)

307D (S/N: DSG1-UP; WZX1-UP)

308C (S/N: KCX1-UP)

Mini Hydraulic Excavator

305.5 (S/N: DCK1-UP; CXZ1-UP)

306 (S/N: MXH1-UP)

308D (S/N: FYC1-UP; GBT1-UP)

Certain Excavators require an inspection of the timing chain tensioner extension after every 1000 hours of service.

Illustration 1	g02456719
Rear View

Illustration 2	g02456737
Area A (1) Tensioner

Remove the tensioner.

Illustration 3	g02725997
(1) Tensioner

Measure the protrusion of the plunger (the length from the tip of the plunger to the farthest wear mark).

If the protrusion of the plunger exceeds 26 mm (1.02 inch), replace the timing chain with a new 390-8680 Chain Kit.