IO-390-D Series Engine Maintenance Manual
72-70
© 2020 Avco Corporation. All Rights Reserved
Page 250
March 2020
IO-390-D Series Engine Maintenance Manual
(2)
Heat the new starter ring gear to approx. 450°F (232°C) in an oven or with a torch.
(3)
Assemble the heated gear on the ring gear support (with the tooth chamfer up).
NOTICE:
As the starter ring gear cools, it will shrink to the support.
(4)
Use a 0.0015 in. (0.0381 mm) feeler gage to measure the clearance between the ring gear
and support at both locations where the ring gear and support surfaces make contact.
Measure around the entire circumference. The clearance measurements must be same to
ensure correct seating of the ring gear against the support face. Different clearance
measurements are an indication of incomplete assembly or warpage and must be
corrected.
(5)
Install the starter ring gear support with the new starter ring gear on the crankshaft flange
per the “Starter Ring Gear Support Installation” section in this chapter.
