INTERNAL ENGINE MODIFICATIONS Valvetrain |Heads | Strokers | Design | Assembly

Why do I keep trashing the same rocker arm?

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Old Apr 9, 2011 | 05:59 PM
  #11  
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I think I would go ahead and take the head off and check everything out before you really mess something up, if you haven't done so already.
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Old Apr 9, 2011 | 06:05 PM
  #12  
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Take a tap and chase the threads in that faulty rocker arm bolt hole.

Use RED lock tite, not blue.

TQ to 22 ftlbs

If the threads are ok, and the rocker arm bolt is good, you have to have a push rod / lifter issue.
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Old Apr 9, 2011 | 06:07 PM
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What am i looking at with the head off? A bad lifter? Is it possible that a bad lifter is causing the bearings to come out of the same rocker twice?
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Old Apr 9, 2011 | 07:52 PM
  #14  
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Originally Posted by TIM Z
Take a tap and chase the threads in that faulty rocker arm bolt hole.

Use RED lock tite, not blue.

TQ to 22 ftlbs

If the threads are ok, and the rocker arm bolt is good, you have to have a push rod / lifter issue.




Thanks been the best advice soo far... The threads check out good and the bolt looks like its good( no galling or layed over threads). The rocker rail may be my culprit from the first rocker that it trashed. The number three rocker pedestal looks good but it has been milled on both sides soo that means it got extremely hot and could have possibly warped it from the first time so that would explain the second time. I will check PR length and preload in the morning. How do you go about checking to see if a lifter is bad? Thanks again PT.net you are the reason I keep on keeping on......
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Old Apr 9, 2011 | 08:30 PM
  #15  
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Bud i understand your frustration!

Hang in there.

After you re- loc tite the rocker bolt. let it sit for an hour , just so it has more than enough time to set up.

I had the same problem as you, my rocker arm kept going loose on my old 5.3 after i cammed it.

Happened 3 times, i even tried putting a helicoil in the rocker bolt hole but i ended up fuking that head up and had to buy a new one from the junkyard.

Luckily replacement 5.3 heads are bout 100$ fully assembled, so if you do have a messed up head a replacement isnt too bad.

I bet you'll be fine though if ya take your time , clean up the threads and re loctite.

good luck.
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Old Apr 9, 2011 | 08:44 PM
  #16  
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I would suggest to remove all of the rockers and switch them to the other side of the engine and vice versa. Keep the pushrods to the same rocker. If the problem follows you know it is a rocker/pushrod. If the problem stays on the #6 intake again, then it is something with that cylinder. If it stays to that cylinder it could be the lifter, valve, valve spring, maybe even hitting on the valve cover. I would check your valve spring, there have been several people that have broken one and it never made a sound. What cam and rockers are you running?
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Old Apr 9, 2011 | 08:44 PM
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Originally Posted by TIM Z
Bud i understand your frustration!

Hang in there.

After you re- loc tite the rocker bolt. let it sit for an hour , just so it has more than enough time to set up.

I had the same problem as you, my rocker arm kept going loose on my old 5.3 after i cammed it.

Happened 3 times, i even tried putting a helicoil in the rocker bolt hole but i ended up fuking that head up and had to buy a new one from the junkyard.

Luckily replacement 5.3 heads are bout 100$ fully assembled, so if you do have a messed up head a replacement isnt too bad.

I bet you'll be fine though if ya take your time , clean up the threads and re loctite.

good luck.
Hes has an LY5 5.3 so it has the 243/799 heads on it so not quite so cheap to replace unfortunately.

This may be stating the obvious but Id start with a new rail, its chewed up a little and doesnt take much at all to throw the rocker geometry up. It also doesnt take much to chunk the needle bearings in the shitty design. You could always order up the comp trunion upgrade that gets rid of the needle bearings.
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Old Apr 9, 2011 | 08:48 PM
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Originally Posted by TIM Z
TQ to 22 ftlbs
Originally Posted by afterburn84
He torqued them to 30ft lbs and I just found out..I replaced it with a new oem one and retorqued every single one of them back to 22 ft lbs
Your problem is right there 22ft/lbs!?!?

You torque them to 22n-m not ft/lbs. You probably stripped the threads in the head. Not good.
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Old Apr 9, 2011 | 08:50 PM
  #19  
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Originally Posted by Dezert1500
Your problem is right there 22ft/lbs!?!?

You torque them to 22n-m not ft/lbs. You probably stripped the threads in the head. Not good.
Thats what i meant.

But i see after reading the quote that he tqed to 30 ftlbs, i was hoping he meant n-m not ftlbs like mistakenley put.
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Old Apr 9, 2011 | 08:54 PM
  #20  
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Originally Posted by 1slow01Z71
Hes has an LY5 5.3 so it has the 243/799 heads on it so not quite so cheap to replace unfortunately.

This may be stating the obvious but Id start with a new rail, its chewed up a little and doesnt take much at all to throw the rocker geometry up. It also doesnt take much to chunk the needle bearings in the shitty design. You could always order up the comp trunion upgrade that gets rid of the needle bearings.
Thats good advice too Cody, Yeah ive never priced Ly5 heads.

Just feel bad for the OP and hope we can get him fixed up.
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