3 Very Loose Rocker Arms upon Head Re-Install - Diesel Place : Chevrolet and GMC Diesel Truck Forums
 
Home Forum Market Place Garage Tuning Library DTC Tool Register Vendors
Go Back   Diesel Place : Chevrolet and GMC Diesel Truck Forums > GM Diesel Engines > 6.5L Diesel Engine
Register FAQ Forum Rules My Replies My Threads Mark Forums Read Advertise

6.5L Diesel Engine Discuss the 6.5 GM diesel engine & associated components. Automatic transmission questions & problems belong in the 4L80/85 - 4L60E - 6L90 Transmission Forum

DieselPlace.com is the premier Duramax Diesel Forum on the internet. Registered Users do not see the above ads.
Like Tree8Likes

Reply
 
LinkBack Thread Tools
Old 04-23-2019, 09:57 PM   #1 (permalink)
Still Bill
Glow Plug
 
Join Date: Nov 2015
Posts: 239
iTrader Score: 0 reviews

3 Very Loose Rocker Arms upon Head Re-Install

Well, I pulled my head and replaced the bent valve. Reinstalled head today. Before removal, all rocker arms were tight to valves. When I went to install the rocker arms, I find that 3 of them are extremely loose - like 1/4" clearance. On one, I can pull the push rod out from under the rocker.



What happened? Things were going so smoothly, until now. I did turn the motor 1/2 turn by hand with head off, if that matters.


Do I just need to crank the engine (by hand or with starter) to pressurize the lifters?

__________________
1995 Grumman P30 6.5L
Offline  
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 04-23-2019, 10:35 PM   #2 (permalink)
Ron Nielson
Diesel Pro
 
Ron Nielson's Avatar
 
Join Date: Aug 2009
Location: Berryton, KS
Posts: 2,249
iTrader Score: 0 reviews

You need to adjust your valves, all of them. I don't know the spec for your truck, mine is .012 inch.


Depending on where in the 4-stroke cycle the crank is, some valves will be tight (they are at least somewhat open), or will have clearance if the valve is fully closed. They are never all open or all closed at any one time.

__________________
Ron Nielson

2008 2500HD LT CCLB/Ally. Line-X, B&W Companion, MaxLoader Springs, Edge Insight CTS, Kennedy Custom ECM
2009 Arctic Fox 5er, Silver Fox Edition 29-5T, 3.6 Onan LPG, SteadyFast Stabilizers
Offline   Reply With Quote Quick reply to this message
Old 04-23-2019, 11:48 PM   #3 (permalink)
Still Bill
Glow Plug
 
Join Date: Nov 2015
Posts: 239
iTrader Score: 0 reviews

Adjust valves? OK, any other opinions?
__________________
1995 Grumman P30 6.5L
Offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 04-24-2019, 12:10 AM   #4 (permalink)
Glagulator
Diesel Superstar
 
Join Date: May 2005
Location: Very south TEXAS, Formerly Wisconsin
Posts: 3,573
iTrader Score: 5 reviews

Is the really loose rocker on the cyl. that got beat?
__________________
There are 10 kinds of people in this world; Those who understand binary and those who don't.

99 CREW LONG SRW C3500 work truck 199k+ mi. orig. motor & trans 4.10, modded engine harness, new oil cooler & lines, all new front end parts and poly bushings, trans poly mount, all new brakes.
96 SUBURBAN K2500 wife's truck 210k+ mi. orig. motor & trans, 3.73...
95 C2500 Suburban 6.5td HO w/p, timing set, HB & pulley, all rubber hoses, modded engine harness, PMD to bumper...
95 C1500 Suburban 6.5td rebuild tranny, convert to DB2, replacing as many parts as I can.
96 C2500 Suburban 7.4L converting to 6.5td w/ DB2, 4L80, 3.73
Offline   Reply With Quote Quick reply to this message
Old 04-24-2019, 01:12 AM   #5 (permalink)
KenDDiesel
Diesel Starter
 
Join Date: Aug 2017
Posts: 156
iTrader Score: 0 reviews

6.2/6.5 use non adjustable valvetrain.
You Mentioned you rolled the motor over?
Could it be you just caused some bleeddown pushing oil out of the lifter?
However even on a bled down lifter you'll have some preload.
But it will just be lifter spring pressure, which isn't much. You'd be able to easily push the rocker down by hand.
__________________
1991 k30 cclb 6.2l 4l80E
1986 k30 cclb 6.2 n/a th400 dually
1984 k30 cclb dually 6.2 banks turbo th400 gear vendor
1985 gmc suburban k20 banks 6.2 t400.
Offline   Reply With Quote Quick reply to this message
Old 04-24-2019, 07:46 AM   #6 (permalink)
Still Bill
Glow Plug
 
Join Date: Nov 2015
Posts: 239
iTrader Score: 0 reviews

Yes, I knew valves not adjustable
.
There are 3 very loose rods. Only one is on the "bad cylinder. Believe it is the exhaust valve (2nd from end in rear). Not the bent intake valve. That cylinder is at TDC now. That piston was 1/2 way down when I turned the engine. So, it makes sense the exhaust valve was open, and would now be "closed".


Anyhow - going out to crank engine over slightly in a few. Did it 100 times in my head while sleeping last night. Will be late for work.
__________________
1995 Grumman P30 6.5L
Offline   Reply With Quote Quick reply to this message
Old 04-24-2019, 08:58 AM   #7 (permalink)
Still Bill
Glow Plug
 
Join Date: Nov 2015
Posts: 239
iTrader Score: 0 reviews

Well, all is good now. I did crank the engine to get oil pressure (GP relay and fuel solenoid disconnected). All valves tight now.


However, I cannot be sure now that I even had a problem to begin with. I recall fully tightening down both bolts on the first rocker shaft. Then, I noticed a very loose valve. On the second rocker shaft, I was more tentative on tightening the bolts. Last night after seeing my "problem", I removed shaft #2 and loosened the first one, but never re-torqued.


So, this morning, after cranking, two valves were still loose on shaft 1. Shaft "looked" bolted-down, but I saw the shaft moving when I cranked. Tightened all bolts fully, and now all valves are tight.


It is possible last night the first shaft was not fully seated, and I never bolted-down the second one. It was late, and mosquitoes were out.



I guess I will never know - unless a valve is loose when I come home tonight.


Thanks for listening.
__________________
1995 Grumman P30 6.5L
Offline   Reply With Quote Quick reply to this message
Old 04-24-2019, 10:44 AM   #8 (permalink)
Still Bill
Glow Plug
 
Join Date: Nov 2015
Posts: 239
iTrader Score: 0 reviews

Thinking about it more, I feel stupid now. Oh well, it was late and time to quit for the evening anyhow.


I initially tightened the first rocker shaft bolt with the small air ratchet, making it tighter than I intended to - snugged bolt up pretty tight. Then, I thought to back off because I wanted to make sure everything was aligned before I tightened them. So, then I just snugged all the bolts up by hand. In the dark, it looked like the shafts were seated, but what I felt by hand-snuggig was just the initial spring resistance. DOH!!


Feel dumb, but happy!
__________________
1995 Grumman P30 6.5L
Offline   Reply With Quote Quick reply to this message
Old 04-24-2019, 11:55 AM   #9 (permalink)
Tommygunner
Diesel Expert
 
Tommygunner's Avatar
 
Join Date: Feb 2010
Location: Northesat Nevada
Posts: 2,894
iTrader Score: 0 reviews

Rocker shaft bolts should be tight to 40 ft lbs with a torque wrench. Not by hand or an impact. Impacts on engine assembly are a big no no.
__________________
The beauty of the Second Amendment is that it will not be needed until they try to take it

If Americans ever allow banks to control their currency. First by deflation then inflation. The banks will deprive the people of all property. Until their children wake up homeless.
1998 GMC K1500 WT, 6.5 TD. 80,000 miles. Auto, 3.73 gears. Remote PMD mounted on the radiator support. KOJO tune WOW! Carter HD lift pump. Feed the beast, GM8 turbo with Hurricane impeller. K&N filter. Ported, gasket matched upper intake. Leroy's braded stainless steel oil lines.
New Bosch injectors. Flow matched 2200 lbs pop
3 1/2" custom Aero turbine exhaust. Nutered Cat
2" Lift RS5000 Shocks. 285 X 17 Bridgestone AT summer tires. 12.50 x 33 x 15 Procomp MTs winter. Powertrax No slip locker in rear.
Offline   Reply With Quote Quick reply to this message
Old 04-24-2019, 12:31 PM   #10 (permalink)
Still Bill
Glow Plug
 
Join Date: Nov 2015
Posts: 239
iTrader Score: 0 reviews

Quote:
Originally Posted by Tommygunner View Post
Rocker shaft bolts should be tight to 40 ft lbs with a torque wrench. Not by hand or an impact. Impacts on engine assembly are a big no no.

Yes, I know, but it is the small 3/8" air wrench. Much less than 40, maybe 20. Was not trying to do final torquing. Just wanted to get bolts seated before torquing and make sure nothing was mis-aligned or binding before final tightening. But, the spring tension fooled me, and bolts still had a few turns to go. Better safe than sorry! Live and learn!

__________________
1995 Grumman P30 6.5L
Offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Diesel Place : Chevrolet and GMC Diesel Truck Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

PLEASE READ! You must check your email inbox for the confirmation link to complete registration. Please check your spam box if you do not see the email in your inbox.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Insurance
Please select your insurance company (Optional)

Log-in


Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
LBZ: Aftermarket Head unit install BajaJames Electrical 7 01-03-2018 08:36 PM
I got a 07 topkick with 7.8 isuzu need torque specs jmcclurg84 Medium Duty Trucks 3 03-15-2017 06:07 PM
6.2: 1993 K2500 Cheyenne Ext. Cab Daily Driver Ruffian Builds 76 01-29-2017 05:05 PM
FOR SALE: New timing set & rocker arms sctrailrider Closed / Archived Marketplace Ads 0 07-12-2016 09:42 PM
ARP Head Stud Install DSDMAX06 Duramax Third Generation: 2006-2007.5 (LBZ & LLY) 1 03-03-2016 06:14 PM


All times are GMT -4. The time now is 07:31 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Shoutbox provided by vBShout v6.2.1 (Lite) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
© AutoGuide