11 · Engine

Changing the flywheel ring gear

Engine overhaul: 1.9 TD (AR67501)Changing the flywheel ring gear

Measure the diameter of the hole on the piston paired with the gudgeon pins and check that it is within the specified limits.

Gudgeon pin hole diameter in pistons
Version before change	Class 1	25.993 ÷ 25.996 mm
Version before change	Class 2	25.996 ÷ 25.999 mm
Version after change	25.994 ÷ 25.999 mm

Calculate the clearance between the gudgeon pins and their seats on the pistons and check that it is within the specified limits.

Clearance between gudgeon pins and seats on pistons
Version before change	0.003 ÷ 0.009 mm
Version after change	0.003 ÷ 0.012 mm

Check that the flywheel ring gear is intact and, if necessary, replace it proceeding as follows:

remove the old ring gear using a hydraulic press.
carefully clean the contact surfaces of the new ring gear and of the flywheel.
evenly heat the new ring gear to a temperature of 80 °C and fit it on the flywheel.
allow to cool in a natural environment; do not force cool.

Inspecting and checking the oil pump

Check that the clearance between the pump casing housing and the driven gear is within the specified limit.

Clearance between pump casing housing and driven gear
0.080 ÷ 0.186 mm

Check that the clearance between the resting surface of the pump cover and the upper side of the gears is within the specified limit.

WARNING: If the clearances are not within the specified limits, change the front cover with incorporated oil pump.

Clearance between pump cover resting surface and upper side of gear
0.025 ÷ 0.056 mm

Links open Amazon search results in a new tab. As an Amazon Associate I earn from qualifying purchases.