CSNMACKS Posted December 9, 2021 Share Posted December 9, 2021 Hello everyone, I am a new user to this site. I work for a construction company that has a small fleet of Mack dump trucks. I haven't much experience with engine maintenance and repair on Macks. We recently purchased this truck from an auction, and after returning home from the purchase (13 hour road trip one way), the truck was turned loose to run the following Monday. Truck came back after 2 hours of work with a bad misfire on the no.1 cylinder. After further inspection a bridge on the intake valves of no.1 cylinder was laying on the cylinder head. Are there a difference in adjusting the valves in the AI engines compared to the E-Tech engines? Quote Link to comment https://www.bigmacktrucks.com/topic/68895-2003-mack-rd600-ai-350-valve-adjustment/ Share on other sites More sharing options...
R.E.D Posted December 10, 2021 Share Posted December 10, 2021 Exhaust valve push rod has a spring.needs to be compressed when taking measurement and when adjusting as well. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/68895-2003-mack-rd600-ai-350-valve-adjustment/#findComment-484664 Share on other sites More sharing options...
Joey Mack Posted December 10, 2021 Share Posted December 10, 2021 if you have power leash, you set the lash to .045" on the inner portion of the exh. rocker arm, and leave the feeler gauge in place, then set the rocker arm lash to .024". rotating the engine is the same procedure.. be absolutely sure you are on the correct cyl. when making adjustments. this engine has ceramic roller lifters for the valves. any 'slap' will crack the roller, then the cam will get chewed up, instantly after starting the engine. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/68895-2003-mack-rd600-ai-350-valve-adjustment/#findComment-484677 Share on other sites More sharing options...
Joey Mack Posted December 10, 2021 Share Posted December 10, 2021 (edited) the intake bridge has a small arrow on the side, this indicate's 'out' flip it over to see the holes for the valve stems, one is round the other is an oval. May I suggest, dropping the oil pan and inspecting the cam.. if you hear something sliding in the pan when you drop it,, more than likely its a roller.... Definatley inspect the cam and lifters thoroughly.. good luck.. jojo Edited December 10, 2021 by Joey Mack Poor spelling 1 Quote Link to comment https://www.bigmacktrucks.com/topic/68895-2003-mack-rd600-ai-350-valve-adjustment/#findComment-484680 Share on other sites More sharing options...
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