A couple of tips for using exhaust manifold clamps

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03yukXL

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As you guys are all aware, the exhaust manifold bolts on the LS motors are notorious for failing. On my '03 3 of them were gone, two on the rearmost port on the driver's side, one on the rearmost of the passenger side (what great luck!). I decided drilling them out was beyond the amount of effort I wanted to spend on dealing with this.

I ordered ARP manifold bolts and replaced the 9 remaining bolts. They all came out with a little effort and penetrating oil. No real drama there.

Installing the clamps was ok, but a couple of things would have made my life easier: Here goes-

For the driver's side rear clamp the one that looks like this go at it from under the car. Remove the 3 bolts for the heat shield right under the steering column. 10mm, two under the the truck, one from above. Just use a long extension. Second, drop the drive shaft. Make your life easier, takes 3 min and its 4 bolts. Let it hang on the exhaust. Next, screw in the "clamp" screw as far as you can before you install, because wratcheting it will be annoying after the bracket is in place. Last, you may have to get a really long extension and, from under the truck, place it under the manifold heat shield and pound it up and out of the way slightly so you can get a wrench on the clamping screw to cinch down on the manifold after the bracket is installed.

For the driver's side, The one that looks like this remove the dipstick tube and as many of the spark plug wires as you think will be in your way. Do your self a favor and try to keep the plug end of the rearmost spark plug wire attached, just remove the coil end if possible. Next, you may find that the heat shield, again, is in the way. Get under it with a long flat screwdriver and pry it up and out of your way so the bracket will sit where it needs to in order to line up with the bolt holes. The threads in those holes are a aluminum so you want to make sure you get it right. Do the back bolt first, then the front. Hook up the spark plugs before installing the dipstick tube.

The brackets do work, but the design could be better to accommodate the heat shields.
 
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Sam Harris

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As you guys are all aware, the exhaust manifold bolts on the LS motors are notorious for failing. On my '03 3 of them were gone, two on the rearmost port on the driver's side, one on the rearmost of the passenger side (what great luck!). I decided drilling them out was beyond the amount of effort I wanted to spend on dealing with this.

I ordered ARP manifold bolts and replaced the 9 remaining bolts. They all came out with a little effort and penetrating oil. No real drama there.

Installing the clamps was ok, but a couple of things would have made my life easier: Here goes-

For the driver's side rear clamp the one that looks like this go at it from under the car. Remove the 3 bolts for the heat shield right under the steering column. 10mm, two under the the truck, one from above. Just use a long extension. Second, drop the drive shaft. Make your life easier, takes 3 min and its 4 bolts. Let it hang on the exhaust. Next, screw in the "clamp" screw as far as you can before you install, because wratcheting it will be annoying after the bracket is in place. Last, you may have to get a really long extension and, from under the truck, place it under the manifold heat shield and pound it up and out of the way slightly so you can get a wrench on the clamping screw to cinch down on the manifold after the bracket is installed.

For the driver's side, The one that looks like this remove the dipstick tube and as many of the spark plug wires as you think will be in your way. Do your self a favor and try to keep the plug end of the rearmost spark plug wire attached, just remove the coil end if possible. Next, you may find that the heat shield, again, is in the way. Get under it with a long flat screwdriver and pry it up and out of your way so the bracket will sit where it needs to in order to line up with the bolt holes. The threads in those holes are a aluminum so you want to make sure you get it right. Do the back bolt first, then the front. Hook up the spark plugs before installing the dipstick tube.

The brackets do work, but the design could be better to accommodate the heat shields.
Thanks for the post. I’m sure it will help others faced with this issue.
 

OR VietVet

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I wonder if it would be worthwhile to remove the manifold bolts in a newer machine and put some never seize on them? What's the chances all of them would come out on a four year old engine.
Good idea but don't reuse the same bolts. Use the ARP bolts when you go back together.
 

Rocket Man

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I wonder if it would be worthwhile to remove the manifold bolts in a newer machine and put some never seize on them? What's the chances all of them would come out on a four year old engine.
I replaced mine with ARP bolts on both my trucks snd I would on any LS based engine. No use taking chances, because once they break it’s a real pain to fix. I wouldn’t use anti seize, not even sure if it would work at that temp.
 

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