Camshaft And Tappets - Yanmar 4JH2E Service Manual

Chapter 2 Basic Engine
7. Camshaft and Tapptts
7. Camshaft and Tappets
7·1 Camshaft
The camshaft is normalized and the cam and bearing
surfaces are surface hardened and ground. The cams have
a curve that minimizes the repeated shocks on the valve
seats and maximizes valve seat life.
(1) Checking the camshaft side gap
The load is received by the standard bearing near the
end of the camshaft by the cam gear, resulting in rapid
wear of the end of the bearing and enlargement of the
side gap. Therefore, measure the thrust gap before
disassembly. As the cam gear is shrink-fitted to the
cam, be careful when replacing the thrust bearing.
camshaft side gap
Printed in Japan
AOA1029-9109SP
camshaft gear
Thrust metal
Side
gap
Standard
0.05 - 0.20
10.0019 -0.0079)
mm(in.)
Wear limit
0.4
(0.0157)
4JH2-Series
Push rod
2·23
Camshatt
camshaft bushing
Thrust metal
(2)
Measure the camshaft height, and replace the cam If it
is worn beyond the limit.
Camshaft height mm( in )
Engine
Standard Wear limit
model
4JH2E
Intake cam
38.66 - 38.74
38.4
Exhaust cam
( 1.5220 - 1.5251)
(1.5118)
4JH2-TE
Intake cam
38.66 - 38.74
38.4
4JH2-HTE
(1.5220 - 1.5251)
(1.5118)
4JH2-DTE
38.86 - 38.94 38.6
4JH2-UTE
Exhaust cam
(1.5299 - 1.5330) (1.5196)