Grit Dog

No issues with the truck but moving to a more remote area and the truck will be a DD again not a weekend vehicle so it will be getting some miles on it.
Good PM to get a valve adjustment or let 'er rip?

jhenson

Wouldn't hurt to check 'em anyways.....but more than likely not needed!

papaduck

My '03 manual says to adjust at 115k miles. I could not do it at that milage and let it go until 123k miles. They were all still within spec but adjusted them anyway to .010 and .020 anyway. I could tell no differance aftwards.

Grit Dog

Kinda what I was thinking. Guess I'm good to go. Thanks

Jeff in TD

I think cummins specifies every 150k, but on the other hand it doesn't take long to check them.

jhenson

Correct!

Kach

Is there a DIY tutorial for this somewhere? Never done it before, but thinking of trying to take this on. Is it more than a guy who's fairly handy with a wrench could handle?

My truck has 137k and seems to have a bit more rattle to it recently...

Jeff in TD

Remove the valve cover, rotate the engine with a barring tool or by the alternator pulley until the TDC mark on the damper is at 12 o'clock.

If both #1 valves are loose then #1 is between compression and power stroke, so adjust intake on 1, 2 and 4 and exhaust on 1, 3 and 5.

If both valves on #1 are not loose it's in overlap between exhaust stroke and intake, so you adjust intake on 3, 5, 6 and exhaust on 2, 4 and 6...

Feeler gauge goes between the rocker and the cross arm.

If the gap is within range (Intake is 0.006 to 0.015 and exhaust is 0.015 to 0.030 with cold engine) then no adjustment is needed...

If out of that range, then set intake at 0.010 and exhaust to 0.020. Tighten lock nut to 18 ft/lbs and recheck after tightening.

Then rotate the engine 360 and do whichever group you didn't do...

My guess is that you will find none out of range, but for peace of mind I'd check them...