2000 Dakota 3.9L, base.

The manual is telling me that I need to turn the crankshaft until TDC lines up with some "V6" mark, and that this is necessary to do before tightening down the bolts on the 3 sets of rocker arms. Taking the timing chain cover off looks like a royal pain of stuff I don't want to do, unless I'm misunderstanding where one looks to sees these marks line up.

But is this necessary? Wouldn't the valves go back to their position as I tighten the rockers down? As long as I get them tightened down to spec, I don't understand why any particular position of the crankshaft is better than any other? The pushrods are just dumb levers, why do they care what height they get tightened down at?

 

this is required...you want the cam on the base of the lobe when torquing the rockers otherwise you will compress the lifers to much; leading to a bent push rod.

 

this is required...you want the cam on the base of the lobe when torquing the rockers otherwise you will compress the lifers to much; leading to a bent push rod.

assuming this is a cam in block engine....put the engine with the #1 cylinder piston as high as it goes- remove the spark plug and put a long wire or screw driver in the plug hole...have someone hand crank the crank pulley bolt....you will either be at tdc on the comp stroke or intake stroke.
put the push rod into the lifters by hand and hold them in place with your hand...have someone move the crankshaft back and then past tdc...if the pushrods both stay down your at tdc on the comp stroke...if one goes up and the other down your at tdc on the intake stroke...rotate the crank 1 turn.

 

Should be marks on the harmonic balancer, and timing cover.... those are the ones you are looking for.

 

But I'm supposed to do this for every cylinder and its TDC position? I've only removed one head, so I'm working on cylinders 2, 4, and 6.

 

...and also, another question but it's not that important. I'm just trying to wrap my head around this.

Say a lifter is all the way up, and I place the pushrod on it. Now I'm tightening down the rocker arm. One end starts to catch the pushrod. As I'm torqueing it further down it acts like a slow see saw and on the other end starts to push down the valve spring. How on earth could that bend the pushrod? It's designed to withstand all that force and then some when the engine is running. I don't understand how I could be introducing more force than the valve spring.

 

cause you want the lifter to ride in its middle position hydraulically. soak your lifters overnight in oil if they are new.
if its fully compressed because you torqued it on the top of the lobe when the engine is started, it will be loose until the rocker pumps up...this temporary play could have the push rod slide out of position and bend.

if you know the firing order/paired cylinders you should only have to turn the engine over 2 turns to make every adjustment.