LLY: headgasket replacement
- Thread starter bigaland4gals
- Start date
SO I found another bent valve victim/thread:
http://www.duramaxforum.com/forum/0...-bad-headgaskets-bent-valves.html#post3515634
Iv had cam pins break and bend pushrods and slam valves into pistons before and the valves were still straight. That's more pressure slamming against it than a leaky cylinder venting into the cooling system.
Please elaborate how the gaskets being bad are bending them on the top side in the valvetrain side.
Please elaborate how the gaskets being bad are bending them on the top side in the valvetrain side.
So the valves were not bent terribly, but they were not true. Coolant does not compress and I think alot of people just assume that if everything looks ok then it is? I figured I have already invested this much time and money into this project I might as do it right ONE time!
thanks
Must have changed the instructions?! And I must have got an old set then. Never had issue with mine. Did them the old way
I called ARP today and spoke with a tech rep. He explained that the old style/type of grease/lubricant they used to use had to be "cut in" which required torquing to 125 3 different times. The new synthetic type lubricant they now use (for the last 5-6yrs):cool2: does not require this "cut in" He told me to torq to 45 then 90, then 125. If able wait overnight and recheck again to 125. the 4 M8 bolts he said do after the mains and torque in 2 equal steps.
Hope this helps:beer
Still doesn't explain the theory on bad gaskets bending valves on the top side.
My truck is in the shop getting this repair now. I wish I had the know how and a garage to do it myself.
Making very slow progress on the replacement. I have been waiting for parts, and I wish I could take more time off. weather also sucks majorly in eastern NC. If its not cold as crap its raining. Anyways, I am painting some of the bolt on stuff, like the intake manifolds and valve covers.
. Anyways, I am painting some of the bolt on stuff, like the intake manifolds and valve covers.Attachments
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Got the head gaskets on only to discover one of the valve stem oil seals had torn from the base and was between the stem and spring. Was able to replace with out removing the head thank God!. Got the ppe's on and making slow progress. The number 7 piston head had some HG ring damage, but the cylinder did not have any scratching. I cleaned it up as best I could and am hoping that there are no problems.
. Was able to replace with out removing the head thank God!. Got the ppe's on and making slow progress. The number 7 piston head had some HG ring damage, but the cylinder did not have any scratching. I cleaned it up as best I could and am hoping that there are no problems.Attachments
![20150115_151100[1].jpg](/forum/data/attachments/21/21288-75c4b0e8e603fd4ce1c86dee53ce82b1.jpg)
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![20150115_134825[1].jpg](/forum/data/attachments/21/21315-e38855dddfe6b0174639026e20ca5771.jpg)
Just discovered that this will be my next project. Low coolant a few weeks ago, topped off after looking for leaks. No heat for a while today and hard radiator hose after it cooled down.
It only took a half gallon to fill back up. I would like to park it but need to drive it though the week while I wait for parts. Going to do the egr cooler delete, fpr, and water pump while its apart. Timing sucks but at least I will have studs when I'm done.
It only took a half gallon to fill back up. I would like to park it but need to drive it though the week while I wait for parts. Going to do the egr cooler delete, fpr, and water pump while its apart. Timing sucks but at least I will have studs when I'm done.
Mine is about to go under the knife as well. I've got all parts, going to commence this weekend. Doing FPR, Studs, LML exhaust manifold, injector harness fix while I'm in there. (Water pump was done not long ago.)
I would HIGHLY suggest getting your heads resurfaced and a valve job.
Don't be surprised if you have some bent valves
I have some pics of my head gasket job on here. Might help, i re sealed timing cover, did cp3 high flow lines, new oil cooler seals, i used grade c gm head gaskets, i got the upper engine gasket set from gm, arp studs, i also did a 3 inch one piece y-bridge. Had the heads milled and a valve grind done. Cant remember what else i did. Painted the frame, put gm's rubber coated brake line kit in too. Big job for sure but not that bad. Ive done alot worse being a mechanic for a living. This job is just time consuming. I cut and welded the passenger side up pipe as well.
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Also need the rocker arm torque sequence too, and valve cover sequence also, upper and lower. And actually GM requests removing these parts and the heads in a reveres bolt pattern also. If you didn't i wouldnt worry about it.
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I would HIGHLY suggest getting your heads resurfaced and a valve job.
Don't be surprised if you have some bent valves
Trust me, my heads will be going to get checked out as well. But, until this thread I've never heard of bent valves being an issue. I'll have to read the other thread that was posted.
Any specialty tools I should buy to make the job easier? I plan on doing it in the truck in my garage. If I had access to a lift I would definitely do it that way.
Compared to last years project of pulling a 460 out of a class C motor home in my driveway this looks a little easier.
Compared to last years project of pulling a 460 out of a class C motor home in my driveway this looks a little easier.
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Probably not any better in the space department. You need a torque wrench, and a good set of line wrenches for the fuel lines. Nothing else too special, air tools would make it easier.
If you have a lift, remove the cab. I did it over the fenders and kicked myself later for not using the lift that was EXACTLY where the truck was.......
You end up disconnecting everything anyways.
Also BE CAREFULL on lly
Some lly blocks have up to 2 bolt holes that are shallower at the back and may cause issues if you install ARP headstuds. I knew this, yet had forgotten by the time I did the job until too late. Had to pull driveside cover again, not fun
Some lly blocks have up to 2 bolt holes that are shallower at the back and may cause issues if you install ARP headstuds. I knew this, yet had forgotten by the time I did the job until too late. Had to pull driveside cover again, not fun