best way to turn over NHC250 engine by hand?

[LCA078]

I will head down to look at a non-running truck and want to turn the engine over by hand to verify it turns freely before I try to jump start it. No idea how long it's been sitting there without a crank so just being careful. What is the best method to do so and what tools do I need to drag down with me?

 

[simp5782]

I will head down to look at a non-running truck and want to turn the engine over by hand to verify it turns freely before I try to jump start it. No idea how long it's been sitting there without a crank so just being careful. What is the best method to do so and what tools do I need to drag down with me?

1-5/16 or 1-3/16" socket on the accessory drive or a 1-1/8" socket on the crankshaft

There is a engine turning tool for the nh855s made by OTC if you have time and want to keep one on hand for future work

 

[WillWagner]

Push down on the fan belts and turn it backwards using the fan.

 

[71DeuceAK]

Following, as someone who has a truck which needs to be barred over to make sure it isn't locked up..granted I suspect that motor is toast...

 

[simp5782]

On a 939 series Small cam fan clutch is normally open setup. without air then clutch will not engage so the fan spins freely all the time even with pressure on the belts

 

[WillWagner]

Well then I guess that won't work. Use a large flat blade screwdriver through the hole in the flywheel housing, if the ring gear aligns with the hole.

 

[LCA078]

Thanks for all the replies. Once I got the truck home, I realized why it hasn’t started in a while- no need to hand turn it yet. I bought it as a parts truck so not too disappointed. Now have to figure out what caused the cam follower to crack out. No idea if this is minor or catastrophic.