SSlammedlt-4

OK, I am trying to set my RR by the crane cams website. I was wondering what lifter preload was and how can you tell if there is any? I am thinking it is when the center of the lifter is pushed in. Please help me I am trying to set my rockers before iI put in the motor to get them close.

Shawn

97WRAITH

Tighten them down intill there is no up and down movement in the pushrods.There is a curtain sequence when doing this are you following this.I don't remember off hand but if you do a search you should find that sequence.Or try shoebox's install site.

Rob.

jonaddis84

Tighten em down like he said until they still spin, but do not move up and down at all, then usually turn around 1/4 turn past that (zero lash) point.

As for order, easiest way i found:

concentrate on one cylinder at a time, whenver say the exhaust is travelling up, the intake will be totally down, and visa versa, try to make sure though that they are more towards all the way open before you adjust the corresponding valve incase you have a lot of overlap on the cam

then just keep bumpin the motor over until you get them all, be sure to keep track on a piece of paper mind you, gets confusing

y5e06

I'm doing this job right now.
Factory service manual says to set zero lash by: tightening down rocker arm and spinning push rod. when you can no longer spin the pushrod, then thats zero lash. You then proceed to tighten the nut down ONE full additional turn.
thats as instructed by GM.
I'm using that method except I'm staying at 3/4 turn instead of full turn.

BadAssed93Z

yeah thats wrong

dont do it that way

tighten 1/4-1/2 turn past no up and down movement

SSlammedlt-4

Will do the , spin the pushrod untill not up and down movement but still spin method. Thanks

WS Sick

I allways use the up and down method then 1/4 turn. I used to use the twist method but discovered that if the lifter is week it will almost colapse completely before you get to that point.

truedualws6

also see

http://web.camaross.com/forums/showt...hreadid=127772

y5e06

um, no. That method is defined by the people who designed, built, and engineered this engine. There are very specific reasons they have these instructions. Other methods may work. To call them 'wrong' is just idiotic.

AsianSensation

The preload for the factory stamped rockers are different than roller rockers. So both instructions are correct depending on the type of rockers you are installing. I gave 1/4 turn preload past zero lash for my roller rockers.

jonaddis84

Never know though, couldve been for better gas mileage maybe? Just a thought. They also tell you to apply the parking brake every time you exit the vehicle!