Some stuff will really whizz you off

[crazy longhorn]

I dont guess it was too bad, busting the ex manifolds off my parts truck(next plant for my 69)....I only have 1 broken bolt in the head. The damn thing had to break about 1/16" below the surface tho.... Now I have welded a nut /washer to the stud sticking out, many times (mostly iron heads or steel to steel app). What is the best way to deal with this "fun"? crazyL

[67ChevyRedneck]

Damn good question. The bolt closest to the DS firewall recently popped off on mine (5.3L). Same thing, right at the head surface. My neighbor had a local shop do his on is 6.0L, same bolt and they charged $250. Think I'm just going to take mine in.

[6772owner]

Im guessing that this isnt in a location you can drill/tap or ez-out the broken stud then?? If so, I guess my next move might be to pull the head and try to remove the stud on the bench by whatever means necessary?

Sorry Im not much help, not sure what else to suggest...

[crazy longhorn]

Originally Posted by 6772owner

Im guessing that this isnt in a location you can drill/tap or ez-out the broken stud then?? If so, I guess my next move might be to pull the head and try to remove the stud on the bench by whatever means necessary?

Sorry Im not much help, not sure what else to suggest...

The engine is out of the truck, on a stand....so drill & easyout is not out of the question. The hard part on the easyout....if I break it....well you know the story. I have heard guys say that you can "mig" a nut on that stud (even if its a bit below the surface), & the weld wont stick to the aluminum. I am pretty fair with a mig.....but a lot spooked about aluminum crazyL

[swartlkk]

I have replaced the bolts on my '04 Tahoe 5.3L & the 6.0L in my dad's '04 2500HD. There were bolts on both that required a drill & ez-out and both had one up against the firewall (passenger side on the Tahoe & driver side on the 2500HD).

The bolts shouldn't be in there too tight. One of the ones in the center on the 2500HD started backing out as soon as I put the large reverse fluted drill bit into it. I started small with a 3/32" drill bit and worked up to a 3/16" reverse fluted bit. Those that still required the ez-out, I just used my small 4-point ez-out. You want to avoid the ones that are spiraled as they can tighten the bolt to the sides of the threaded hole. Get the ones that have straight 'teeth' along the edge to limit the amount of expansion in the bolt.

All in all, I had to drill & ez-out 6 bolts total. The 2500HD had 8 bolts broken off, 5 of which were broken off flush or actually recessed in from the gasket surface! My Tahoe only had 3 broken off & 2 of them just had the heads snap off.

[6772owner]

Well thats a lot easire to do on an engine stand then!

I agree with Swartlkk, do what he said!

[swartlkk]

This is DEFINITELY something that is easier on an engine stand. It still isn't impossible to do correctly with the engine installed, even with the rear most bolts. You just have to either get creative or get the right tools. I ended up borrowing a right-angle air drill from work to do the passenger rear bolt on my Tahoe. It was the only way to get at it straight on.

[crazy longhorn]

Thanks a bunch for all the input guys I have stepped back from this prob ,for thoughts,but the harness is bagged & tagged, & I picked up a couple pcs today(LS lift plate, & the 1" setback brackets). Just so you know, this 5.3 is going in my old longhorn I feel it still applys to this gen truck, so I posted here....again, many thanks. crazyL

[clinebarger]

I would drill it out & Helicoil it, The size is 8mm x 1.25. Center punch it first, Start with a small bit & gradually increase size of the bit.

[bighaas79]

Originally Posted by clinebarger

I would drill it out & Helicoil it, The size is 8mm x 1.25. Center punch it first, Start with a small bit & gradually increase size of the bit.

I have done as clinebarger said, to drill out and gradually get larger with the bits, but I have gotten lucky numerous times that once the walls of the broken off bolt get thin and the heat generated from the drilling, whats left of the bolt will actually spin out using a pick, leaving the original threads fine to use again. NOT a gauranteed result however lol.

[swartlkk]

Here is a picture of the ez-out I used for both engines:


And the bolt extractor set I used for those that only snapped off at the head of the bolt:


The ez-out was from NAPA and the bolt extractor set was Craftsman.

If you have broken exhaust manifold bolts, don't let them go too long or you could end up replacing the exhaust manifold. The 6.0L passenger side manifold had been loose for quite some time. The additional movement & vibration cracked the manifold:

[edhtrd71]

Dont work to hard drillin it out till you try to weld it. If you are descent with a mig just use a nut and fill the hole. The weld will not stick to the aluminum and the heat will loosen up the loctite. The bolt will spin right out. I have drilled out many ex manifold bolts and they are almost always the rear bolt on the head. I have no welding skills so my coworker buddy does the welding for me. If he is not around I have to drill and easyout. It will take you 5 minutes tops with the welder.

[crazy longhorn]

Done deal! I opted to drill it....all the original threads are pretty much intact. The first 1/4 " in is a tick loose, but all good after that. The threads go about 1 " deep, so I doubt there will be an issue? thanks to all the guys, crazyL

[67mater]

I was able to weld/nut the driver's rear bolt out and it was broken 1/16" below flush. Royal pain and took many tries but it can be done in place.

[crazy longhorn]

Looks like a good "save" crazyL