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M38 A1 How to set valve clearances
Posted: Tue Oct 28, 2008 3:45 pm
by Russell
Hello, I have just joined and this is my first post on this forum.
I have just replaced the head gasket on my 1952 M38 A1. I need to reset the inlet valve clearances. The information I have appears to say to warm up the engine, remove the cover and check and set the clearances with the engine running - can anyone confirm that that is correct or have I misunderstood? Thanks.
Posted: Tue Oct 28, 2008 3:53 pm
by Ryan_Miller
Hey,
Go to the M38/M38A1 section of the downloads here on this website and there is the engine maintinance TM you can download.
Posted: Tue Oct 28, 2008 4:52 pm
by GPA
Valve adjustment on a running engine? On some hydraulic valve lifter equipped engines, maybe, but don't do it on your Jeep. Engine must be off and cold (not running for at least 4hours). The adjustment itself is very simple, if you follow the TM9-8014 or the instructions in the download section as Ryan recommended. If you ran the engine and you have to retorqe the head, repeat the adjustment after retorque. If I were you I would check and adjust the exhaust valves too.
Posted: Wed Oct 29, 2008 9:36 pm
by wesk
Dynamic (moving/running) valve adjustments are usually only performed on engines with hydraulic lifters.
Mechanical lifter engines are usually adjusted static and cold.
The procedure can be found in two places for the M38A1:
TM 9-8014 starting on page 109 at paragraph 110. Intakes- 0.018" and exhausts- 0.016".
TM 9-8015-1:
Exhaust page 121 paragraph 106. Adjust to 0.016 to 0.017".
Intakes page 129 paragraph 114. Adjust to 0.018 to 0.020".