what am i supposed to spin to make the motor turn in the truck and what size is the socket?

[stamina]

i have the valve covers off and i’m spinning the nut behind the fan with a 36mm wrench and i don’t see the rockers or pushrods moving, am i spinning the wrong thing? and if i’m supposed to spin the bottom pulley to turn the motor, what socket am i supposed to use?

 

[RonD]

Yes, you need to turn the crank shaft bolt inside the lower crankshaft pulley, all spark plugs removed

Try 19mm, I think that was 4.0l size

 

[stamina]

Yes, you need to turn the crank shaft bolt inside the lower crankshaft pulley, all spark plugs removed

Try 19mm, I think that was 4.0l size

it isn’t necessary to remove all of the plugs is it? just makes it easier to turn i thought

 

[RonD]

Yes, but its also possible to break the crank bolt, not likely but possible

Take the spark plugs out, if you have the valve cover off

 

[stamina]

Yes, but its also possible to break the crank bolt, not likely but possible

Take the spark plugs out, if you have the valve cover off

is there anything i should do after valve adjustment? like before i put the covers back on ? should i run it for a little while then maybe adjust again or just run to check if the noise is gone then shut her off and reinstall if the noise is good?

 

[Eddo Rogue]

Its in there...I use a 1/2" drive socket and very short extension to bring out just far enough for the breaker bar to fit between the radiator and crank pully. I think it s a 19mm, mine might be a 17mm.

 

[RonD]

2.9l valve train noise is usually low oil flow from worn cam bearing or a failed lifter

You shouldn't run the engine without valve cover(s), oil will pour off the top of the head and onto exhaust manifolds, makes a real mess

Adjusting rockers is usually meant for solid lifters, but when re-assembling valve train after re-installing head it is needed
on the 2.9l
Put a cylinder on TDC
Loosen one valves rocker on that cylinder until push rod is loose, not touching push rod
Tight down until rocker is just touching push rod, that's called 0 Lash
Tighten rocker nut 1 and 1/2 turns, best to use a breaker bar, not socket wrench so you can keep track
Some like 1 and 3/4

Do next valve in that cylinder same way

Set next cylinder at TDC
Repeat until done

 

[RonD]

And just a heads up when adjusting hydraulic valves, which is what you have
After you have adjusted the rocker, the 1 1/2 turns, try to twist the push rod with your fingers, it should turn but be hard to turn, if its easy to turn then lifter is bad

You will know, after you have adjusted a few, and twisted a few, what its suppose to "feel" like when twisting it


A hydraulic lifter has a spring inside that applies the tension on the push rod, seen here: https://www.wot-tech.com/images/articles/lifter_preload.gif

This adjustment is called "pre-loading", you are pushing the spring down, about 1/2 way, so that spring pressure is what makes the push rod hard to twist
If its easy to twist then the spring is broken, and that will cause the "tick, tick, tick" noise, and no way to adjust that out
Often called a "collpsed lifter" when the spring breaks

And DO NOT adjust it down more, or you WILL lose that cylinder, as over tightened lifter will hold its valve open a bit, which means low compression and if it does fire then burnt valves will be the result $$$

Lifter also has 2 or 3 valves inside that allow oil in, and then as lifter is compressed, oil is pushed out, up the push rod
The oil also slows it's compression taking away stress on the spring, the "hydraulic" part of hydraulic lifter

The oil for the lifters comes from the two center cam bearing in the 2.9l, a continuation of a main oil passage
When the cam bearings get older, like all bearings, they get a wider gap for the oil to flow out
More oil flow out of the Cam bearing gaps means less oil flowing to the lifters...............so "tick, tick, tick"

And while this can be EXTREMELY annoying, the engine is not being hurt in any way