I believe the rocker arms ride on the cam lobes as opposed to having lifters. I don't see you being able to get the valve springs off with the head mounted but I could be wrong. I just don't see how your gonna be able to compress the spring to get the retainers out.
Replacing lifters without removing cams?
Hello all, I've decided to remove the valve cover to my 3.5L 2005 engine when I get a chance, to do a checkup (thanks to RockAuto's $10 intake manifold gasket!).
I have in my possession a full set of valve springs (with retaining hardware), rocker arms, and lifters, from when I was convinced I had the head issue everyone was talking about on here (turns out it was a dirty MAF sensor, and a bad MAP sensor).
Can you replace the springs, rocker arms, and lifters without touching the cams or the timing? While I'm in there I'd like to, but I really don't want to touch anything related to timing. I have a lot of no-snag, no-lint paracord that I think I can use to keep the valves from falling into the cylinder if it's possible.
Also, there's probably different names for those components for OHC engines. Old habits die hard, so don't shoot me for calling them the wrong names, haha.
I have in my possession a full set of valve springs (with retaining hardware), rocker arms, and lifters, from when I was convinced I had the head issue everyone was talking about on here (turns out it was a dirty MAF sensor, and a bad MAP sensor).
Can you replace the springs, rocker arms, and lifters without touching the cams or the timing? While I'm in there I'd like to, but I really don't want to touch anything related to timing. I have a lot of no-snag, no-lint paracord that I think I can use to keep the valves from falling into the cylinder if it's possible.
Also, there's probably different names for those components for OHC engines. Old habits die hard, so don't shoot me for calling them the wrong names, haha.
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Here's an animation. The cams sit straight on top of the valves no rockers at all. Idk if this is how our motors are tho
http://youtu.be/wQPh2OdBGgI
http://youtu.be/Hhc6xM0wjKQ
http://youtu.be/wQPh2OdBGgI
http://youtu.be/Hhc6xM0wjKQ
I have a spring compressor tool from when I rebuilt a 305ci small block. I wouldn't be surprised if it didn't work (or worked but gouged the cam lobes).
The second link shows it better
I ordered what I would call roller rocker arms from GM parts direct. If I'm not mistaken, the things I call "lifters" are really more or less oil pumps. I'll see if I can't post the valve train diagram I found earlier.
I thought the cam pushed on the top middle roller of the rocker arm (which is floating). The side away from the cylinder is pushing down on the lifter (which has oil access). The side closer to the cylinder pushes down the valve.
I think I remember reading that rocker arms can fall out. They're not bolted down like old pushrod engines.
I thought the cam pushed on the top middle roller of the rocker arm (which is floating). The side away from the cylinder is pushing down on the lifter (which has oil access). The side closer to the cylinder pushes down the valve.
I think I remember reading that rocker arms can fall out. They're not bolted down like old pushrod engines.
You might want to try using an OHC lever type valve spring compressor but the cam base circle may interfere with removing the lifter from its bore.Can you replace the springs, rocker arms, and lifters without touching the cams or the timing? While I'm in there I'd like to, but I really don't want to touch anything related to timing. I have a lot of no-snag, no-lint paracord that I think I can use to keep the valves from falling into the cylinder if it's possible.
2
Here's a website with the cutaway of a later-model 5 cylinder. Also, on GM Parts Direct, the engine is listed as having rockers and lifters. The cam is over the middle of the lifter, which is floating.
Here's the website:
Tech Feature: Straight Up Look at the Vortec 3500 Straight-Five Engine
Let's see if I can't get the cutaway image posted:
![]()
Here's the website:
Tech Feature: Straight Up Look at the Vortec 3500 Straight-Five Engine
Let's see if I can't get the cutaway image posted:
You just might be able to remove the lifter out of its bore once the roller rocker is removed from the picture.
Just be sure to keep each piston you're working on at TDC otherwise you may drop a valve inside the cylinder if the keepers fall out.
Just be sure to keep each piston you're working on at TDC otherwise you may drop a valve inside the cylinder if the keepers fall out.
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