Rocker Torque Procedure

rogersw8n

Original poster
Member
Dec 24, 2020
4
Canton, GA
Hello Merry Christmas. My questions below are from a fully disclosed, curious learner, rookie.

My 2011 Suburban with 208k miles recently sounded as if a lifter failed. Upon taking it apart, I confirmed the #4 lifter had failed. I bought a kit to replace all lifters. While apart I had the heads milled and valves pressure/vacuum tested. Tests were good. Heads were milled down .008". I reassembled everything, new head gaskets and bolts. I followed the torque head torque sequence. Upon start I had a tick in the engine. When I put the engine back together, I did not realize I had to adjust the valves. I just put the rods in, installed the rockers and guide and torqued each to 22 ft-lbs where they landed. After the tick, I researched the tick and realized I should pre-load the lifters. So, my first step to resolve the tick was a valve adjustment using EOIC. I started the Suburban and the tick was worse. I noticed an exhaust smell and sure enough found that some of my exhaust manifold bolts were not tight. I torqued to spec, 11 ft-lb on pass 1 and 15 ft-lb on second pass. Smell went away. The tick still was still there. I researched EOIC again and realized I was wrong when I torqued the intake. I reperformed the procedure.

I ran the procedure like this starting with the driver side head:

1. First my point of reference, going from front of the engine to the rear (firewall) the rockers are 1 Intake, 1 Exhaust, 3 I, 3 E, 5 then 7. On the passenger side going from front to rear (firewall) the rockers are 2 Exhaust, 2 Intake, 4, 6, 8 like that correct?
2. So following that reference starting with cylinder 1, when I rotated the crank, as the exhaust barely began to open as indicated by the push rod rising, I torqued the respective intake. Then I continued turning the crank until just before the intake closed. I then torqued the exhaust. I determined the intake was almost closed by touching the I and E rockers with my fingers and roughly measuring height.
3. I did this one cylinder at a time, down the driver side, then down the passenger side finishing with cylinder 8.

Upon restart, it sounded about the same still to loud. It is a metal ticking, I feel pretty certain. When I give the engine gas the ticking gets faster not louder. It is consistent from startup to a warm engine. The strange thing to me and my first question is, the ticking sound is louder now than when I just put the push rods in and torqued them where they landed. So, for a stock cam with stock push rods and new lifters, what is the procedure to torque the rockers. I am going to wait until the weekend before I retry again but instead of using the EOIC method I was going to try the TDC method. That seems to be the recommended method for stock engines. Thank you in advance for your guidance.
 

mrrsm

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Oct 22, 2015
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Welcome to GMT Nation...and Happy Holidays...

Assuming that your Suburban still has the unmodified 5.3L Engine and not a 5.7L Motor, the procedures for installing the Rocker Arms require No Special Methods for individual Hydraulic Roller Rocker to Push Rod Adjustments. The only cautionary note is that when installing the RRs... having to ensure that the Intake and Exhaust Valves are closed with the Lifters in contact with the Cam Lobes being close to their Base Circles.

Your profile mentions that you performed some work involving the AFM (DOD) on your Engine and perhaps you could describe more information about that work... distinguishing whether you maintained the Stock-As-A-Clock DOD configuration...or used a "DOD Elimination Kit". Please list anything not GM OEM Standard to your 5.3L Engine if such components have been installed.

The one thing not covered in your repair description efforts in Post #1 is very important. I've read your impressions of have "Stock" components presently installed in your Build. However, as soon as your Machinist Milled your Engine Heads... He changed the Inner Geometry of the Push Rod Distance as well as increasing the Cylinder Combustion Compression by incidentally "Adjusting the Quench".

Presently, your "Stock" Push Rods might just be a Little Too Long. The only way to be certain of this relationship would be to use THIS Tool... and measure PRECISELY what the TRUE Push Rod Lengths needed are right now:


CRANEADJUSTABLEPUSHROD1.jpgCRANEADJUSTABLEPUSHROD2.jpg

You will also require a Decent Digital Micrometer Caliper Gauge Set LONG enough to be able to accurately measure the Full Length of the Push Rods when using the Crane PR Length Measurement Tool(s):


MICROMETERCALIPERS12INCH.jpg

Using Stock Push Rods that are either TOO Long or TOO Short can create unexpected Mechanical Contact and accelerate Wear and Tear of the Rocker Arms, Push Rods, Valve Guides and Valve Seats. Damage can likewise occur with the Hydraulic Roller-Lifters and may even keep the Valves from completely closing, ruining compression, combustion and risking Valve to Piston Impacts.

Shaving even a minuscule amount of Metal (0.008") from the under-head surface can have important, non-trivial consequences for Compression and Ignition Timing; enough even to demand using ONLY High Octane Fuel afterwards to eliminate *Pinging* caused by Pre-Ignition from the use of Low Octane Fuels.

Ordinarily, these situations can be adjusted by employing slightly thicker gaskets in order to "Keep The Quench" right where it should be. The PCM may even require a Modified Tune to take these Non-Stock circumstances into consideration if the Engine Idle and Performance at Higher RPM do not seem responsive.

There are Speed and Performance Retailers online that will make you a set of Custom Length Push Rods unless you can find some Shorter Ones to match the Crane Tool Measurements. Good Luck.
 
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rogersw8n

Original poster
Member
Dec 24, 2020
4
Canton, GA
Thank you for the prompt reply. I did not delete the AFM. I replaced all lifters with new AFM lifters or standard lifters as appropriate from Northern Auto Parts. Cylinders 1, 4, 6, and 7 are AFM. The engine is a 5.3L LS3 LMG, Vin "0". I am hoping I do not have a push rod length issue. My thought is to still try the TDC method this weekend. If that does not help, then I'm measuring push rods, I think.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
.008" milling of the heads would be inconsequential as far as the pushrods are concerned. Pushrods are only available in .025" different lengths (i.e. 7.375" instead of the stock 7.400"). Have you checked the rockers that are all tight on their valves? In other words, not loose like when a DOD lifter is collapsed? And is the noise just from one lifter?

Did this kit use OEM GM parts or aftermarket? I'm thinking that one of the new lifters is bad.
 

rogersw8n

Original poster
Member
Dec 24, 2020
4
Canton, GA
The site does not indicate they were OEM parts at Northern Auto. Regarding TDC, how do I find TDC with the engine still in the car. I see images with it out but not while still in the vehicle.
 

mrrsm

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Oct 22, 2015
7,639
Tampa Bay Area
You won't need to know the TDC Position of any individual Cylinder if you follow along using THIS Technique to install the Push Rods and adjust the Roller Rocker Fasteners... by Feel, by Observation and using a Torque Wrench. Don't forget... Before installation... Measure each Push Rod for Length and then Roll them all out along a very flat surface and shine a light in behind to see if any have become Bent in the Slightest or damaged on the Tips either before, during or after this situation occurred:


Watch for THE WARNING this Guy provides about him (Nearly) Stripping Out a Roller Rocker Bolt Hole after allowing Motor Oil to partially fill up the Blind Threaded Holes inside the Aluminum LSA or LS3 Engine Head and almost Hydro-Locking them. Be certain to Blow Out those Roller Rocker Fastener Holes before installing them. Good Thing he was being Cautious!


Also, this problem is very rare, but double check that ALL of your Roller Rockers rotate on their "Trunnion Axles" with their Roller Bearing Needle Bearing Retention Cups and Bearings intact and in place for stability. Make certain that none have any wobble whatsoever, just in case any one of them has gone sideways and lost its uncaged needle bearings.

Be sure that the "Half-Moon" side of the "Trunnion Axles" fits into the 'Half-Moon' slots in the Pedestal so the fasteners mate with the Flat Side of the Trunnions before snugging things up and then putting 22 Foot Pounds of Torque when finishing.
 
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rogersw8n

Original poster
Member
Dec 24, 2020
4
Canton, GA
Hello everyone. I appreciate everyone's replies above. I wanted to give you an update. I was hoping it was going to be good news but its not. The ticking in the engine still exists. It does seem to get better as it runs longer. I have driven it 260 miles. At mile 258 I got a check engine light. I went immediately to an Advanced Auto and read the codes. I have a P0300 and a P219A. I have been reading some about this and given the work that I have done to the engine it is probably an issue with the valve adjustment. I followed the TDC method on 12/25 actually. Things seemed to go well. My research has lead me to the below items to check. Any further input would be appreciated.

  • Leaking or contaminated fuel injectors
  • Low fuel pressure or running out of fuel
  • Leaking evaporative emission (EVAP) canister purge valve
  • Exhaust or intake air system leaks
  • Exhaust gas recirculation (EGR) system
  • Positive crankcase ventilation (PCV) system is leaking or the valve is stuck open
  • Ignition system
  • Incorrectly seated engine oil dipstick, tube or oil fill cap

I have always thought the ticking seemed more prominent on the drivers side of the engine. Is that bank 1? Another thing to note is on the driver's side exhaust manifold, one of the exhaust ports is starting to rust where all 7 of the others still look good. Could that be an indication? I am going to loosen and retorque the exhaust bolds. The torque is low according to the manual, 11 ft-lbs on the first pass then 15 ft-lbs on the second.

Thank you in advance for your time.
 

mrrsm

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Oct 22, 2015
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I know this is an "Aging" Thread...but I forgot to ask the OP whether at the time of the Engine Head R&R ...Did he Clean. Flush Out and Pre-Lube The New (Hopefully Delphi or ACDelco Brand) Replacement Camshaft Roller Lifters at the same time?

Was there any Damage in evidence to any of the Old Roller Lifters? Did he examine the Camshaft Lobes through 720 Degrees of Rotation while viewing them with a 7-9mm Bore-Scope? If these issues were not looked at... as a belated follow up suggestion... Watch what Brian from Briansmobile1 Youtube Channel did in response to THIS particular situation:

 
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