Pushrods still spinning after torquing down rocker arms

Supercharged111 said:

I prefer hydraulic fluid myself.

Click to expand...

Supercharged111 said:

I prefer hydraulic fluid myself.

Click to expand...

someotherguy said:

Just as a point of info, the rockers in that engine are non-adjustable, so the bolts do simply torque down to spec. But following the factory service manual procedure is highly recommended and you can find the link to free downloads of them at the top of the Engine forum here, in the "sticky" posts.

Why were the lifters replaced? We can assume valvetrain noise, or did you actually have lifter failure? Miles on the engine?

Richard

Click to expand...

Schurkey said:

Unless the valvetrain has been modified, there IS NO ADJUSTMENT for lifter preload.

Mark IV big-blocks had adjustable rockers just like small-blocks. Gen 5, 6, and 7 big-blocks have "net lash" rocker system. They're torqued to spec, and the geometry is worked-out so that it automatically achieves acceptable lifter preload.


You wasted eight hours. "Soaking" lifters does nothing useful.


Torque the rocker bolts to spec using a torque wrench, and walk away. There is no adjustment on the stock valvetrain system.

It is possible to convert to the adjustable-style valvetrain, the easiest way is via special rocker studs and nuts. I did this on the Vortec heads I ran on my boat for a few seasons.


I use ATF since it's thinner at room temp than most engine oil. Pumping them full of oil assures that the lifter can pass oil through to the pushrod seat, and allows me to verify the leakdown rate. HOWEVER, you then need to allow extra time to adjust the rockers, as the oil trapped in the lifter will need to bleed out as the lifter plunger gets preload. Failure to allow the bleed-down can result in the valves being forced open, and if the piston is at TDC, it's possible that the valve could be bent.

In the process of pumping them full of ATF, some will inevitably flow onto the side of the lifter...which is good. Make sure the lifter side has a film of lube when you drop it into the lifter bore.

You must be registered for see images attach

You must be registered for see images attach

Some ATF or engine oil on the roller bearing of a roller-lifter would be useful. Don't install 'em dry.

Click to expand...

Schurkey said:

Is 40 ft/lbs the specified torque?

Look up the procedure in the service manual. Far as I know, you just torque 'em down...but I've been wrong before.

Click to expand...

rebelyell said:

Do NOT try to fill hydraulic lifters ...Do NOT soak em, Do NOT fill em.

Click to expand...