Valve Adjustment??

[SmokeShow]

Does a person ever really need to do this as preventative/tune-up maintenance on a duramax? If so, proceedure and acceptable specs would be sweet. :angel:

Was restless last night trying to go to sleep and thought about this so I'm asking.


C-ya

 

[dynarex]

pretty sure they are hydraulic-no adjustment needed

 

[MAXLLY]

IMHO, i would say no. They are hydraulic rollers, unless i screwed up the original adjustment at build time and they aren't makin' any noise, they are good. You can change characteristics a little with a tighter set up and a looser set up, but at what cost/benefit?

 

[MAXLLY]

IMHO, i would say no. They are hydraulic rollers, unless i screwed up the original adjustment at build time and they aren't makin' any noise, they are good. You can change characteristics a little with a tighter set up and a looser set up, but at what cost/benefit?

I lied... I looked at the pictures i took and they are solid rollers. Don't crucify me, this is the first DMAX build i have done.

Sorry man.

 

[JOHNBOY]

Will let it slide this time!

Yes they are solid rollers.

Mitch
To answer your question. Unless it is noisy I would leave alone. My stick truck was in spec even after the high RPM beatings it took. IMHO Don't worry 'bout it!:rofl:

 

[dynarex]

wow there solid lifters-wheres the adjustment/lock nut on the rocker arm?
cool learned something again on this site!

 

[SmokeShow]

Will let it slide this time!

Yes they are solid rollers.

Mitch
To answer your question. Unless it is noisy I would leave alone. My stick truck was in spec even after the high RPM beatings it took. IMHO Don't worry 'bout it!:rofl:

IMO, my truck is louder (rattle - and it is louder, even on the stock tune) than others I hear, like my fiance's identical truck with about 75K more miles than mine.

Just thought maybe valve adjustment could be something else to add to the list of things to do.

John, you mentioned yours as being "in spec". What is considered "in spec" - looking for numbers.


C-ya

 

[02freighttrain]

The spec is .012 cold........ This is pretty sloppy compared to a gasser. I run mine @ .010, don't ask why. (.002) more lift.

They are a total pain in the ass to get to, especially the drivers side. If they are not noisy, forget about it. Most of the time a motor will sink the valves in the head a little after high miles and tighten up the lash. This may be why the factory spec is fairly heavy on the Dmax, considering it is made to last a while (high miles).

The possibility of screwing up something taking it all apart to adjust the valves ain't worth it.imho.

 

[05lly2500hd]

ok I'm gonna have to do this when I recieve my shortblock.
I'll be installing heads and all myself.
Any pointers?
I have a copy of GM's service manual on my pc, but this is the most intimidating part to accomplish at least for me.
Thanks ahead.

 

[mvnvltn]

Its easy to do. Only two crank rotations required for proper adjustment.

 

[02freighttrain]

This may Help.






Adjustments

Valve Clearance Adjustment







Remove the fan clutch.
Remove both upper valve rocker arm covers.
Rotate the engine in the normal direction and put the number one piston at Top Dead Center (TDC) of the compression stroke. Number one cylinder is right side front. While turning the engine watch the intake valve to open and close. Align the mark on the crankshaft balancer with the pointer on the engine.






Loosen the valve clearance adjusting screws for the valve being adjusted.
Insert the feeler gauge between the tip of rocker arm and the valve bridge.




Notice: Refer to fastener Notice in Service Precautions.



Adjust the intake and the exhaust valve clearance to 0.3 mm (0.012 inch) with the engine cold. Shown are the valves that can be adjusted at number one COMPRESSION stroke TDC.
Tighten valve adjusting screw lock nut to 22 Nm (16 ft. lbs.) .






Turn the engine one turn in the normal direction and put the number one piston at Top Dead Center (TDC) of the exhaust stroke to adjust the remaining valve clearance. While turning the engine watch the exhaust valve to open and close. Align the mark on the crankshaft balancer with the pointer on the engine.






Loosen the valve clearance adjusting screws for the valves being adjusted.
Insert the feeler gauge between the tip of rocker arm and the valve bridge.






Adjust the valve clearance to 0.3 mm (0.0112 inch) with the engine cold. Shown are the valves that can be adjusted at number one EXHAUST stroke TDC.
Tighten valve clearance adjusting screw lock nut to 22 Nm (16 ft. lbs.) .
Install both upper valve rocker arm covers.
Install the fan clutch.

 

[05lly2500hd]

Thanks!

 

[05lly2500hd]

Here are the drawings I have. What I'm confused about and is probably a stupid question, but remember I've never done this before; is how do you tell compression stroke from exhaust? By the postition of the valves/rockers?
Like say cyl 1,3,5,7 intake and 1,2,7,8 exhaust are open with cyl #1 @ TDC on the compression stroke.
And
2,4,6,8 intake and 3,4,5,6 exhaust are open on the exhaust stroke of #1 TDC.
Is this it? That's what it seems from the manual but not sure?

 

[02freighttrain]

Here are the drawings I have. What I'm confused about and is probably a stupid question, but remember I've never done this before; is how do you tell compression stroke from exhaust? By the postition of the valves/rockers?
Like say cyl 1,3,5,7 intake and 1,2,7,8 exhaust are open with cyl #1 @ TDC on the compression stroke.
And
2,4,6,8 intake and 3,4,5,6 exhaust are open on the exhaust stroke of #1 TDC.
Is this it? That's what it seems from the manual but not sure?

Not a stupid question....... Turn the motor over while watching the intake valve on number 1 cylinder. When it opens, keep turning the crank until it closes then continue turning the crank until the TDC indicator lines up on the Balancer. That will be TDC. One comment, it is not recommended to turn the balancer backwards if you go past TDC. It's always better to go through process again (only moving the crank in the normal rotation direction. Also pull the glow plugs. It will eliminate the compression resistance while turning it over.

Hope this is not confusing.

 

[05lly2500hd]

Not a stupid question....... Turn the motor over while watching the intake valve on number 1 cylinder. When it opens, keep turning the crank until it closes then continue truning the crank until the TDC indicator lines up on the Balancer. That will be TDC. One comment, it is not recommended to turn the balance backwards if you go past TDC. It's always better to go through process again (only moving the crank in the normal rotation direction. Also pull the glow plugs. It will eliminate the compression resistance while turning it over.

Hope this is not confusing.

actually, that clears it up a bit. I think I've got it now, thank you!

 

[JOHNBOY]

Good info Steve.

Mitch

By in spec I meant they checked at .012. There are all set at .01 know just like Steve.

 

[mvnvltn]

Take the #1 glow plug out and put your finger over the hole when rotating the engine. If you don't already have the glow plugs out.