Removing rounded exhaust bolt?

[dlundblad]

The cat on my truck needs replaced, but it looks like I wasn't the first one who attempted it. On the exhaust side, 1 bolt broke off effortlessly, which tells me it had been broken for some time. The other 2 are completely rounded as is the 02 sensor.

Perhaps I could get a nut splitter in there? A few parts stores have them, but they have 1 star reviews. Thankfully the engine side bolts look fine, but they won't budge. I'll pick up a MAPP gas torch after work. 5 mins of heat per bolt should do the trick I hope.

Perhaps heat and my rounded bolt remover tools would do the trick. It just stinks because the bolts are sized between the 2 tools because they are missing material from being rounded and rusted. The one that I should be using for it hardly fits on whereas the next size up is too big.

So, anyone have any experience with a nut splitter and if so, what brands do you guys recommend?
Same with a decent set of rounded bolt removers. I've had great luck with my compact Sears set, but they aren't doing me much good on this job.

I really don't want to have to take it somewhere, but it is what it is.. They would probably use an oxygen-acetylene torch and get all 6 off effortlessly. Thanks everyone.

 

[JC1]

I have the cheap nut splitter from Harbor Freight. Works OK for those rust exhaust nuts and bolts.

 

[Shannow]

Grab a cold chisel, and start "tapping" the nut off the way that it would want to come off.

That will also act as a nut splitter, expanding it some.

If it's a bolt, it doesn't work well.

 

[HangFire]

Originally Posted By: dlundblad
Perhaps heat and my rounded bolt remover tools would do the trick. It just stinks because the bolts are sized between the 2 tools because they are missing material from being rounded and rusted. The one that I should be using for it hardly fits on whereas the next size up is too big.

Some pictures would help. A lot of what you can try is determined by a.) access and b.) how much collateral damage you're willing to tolerate. In your case, since you are replacing the Cat, damage to the Cat won't matter.

If you can get in there with a drill, drilling it out is also an option. I bought a right angle air drill because that's the smallest package I could find, and some shorty left hand Cobalt bits. Doesn't have to be left hand twist, but exhaust components tend to be rock hard due to heat cycling so a quality bit is required.

Cutting/grinding off the bolt head is also an option, at least on exhaust systems where the head is holding things together, you don't have to worry about the rest of the threaded shank because it's threaded into the far side or a nut, and you can pull the pieces apart once the bolt head is gone.

 

[StevieC]

Depending on the room you have you can use a thin cutting wheel on a pneumatic grinder to split the nut on the side.

If that doesn't work then heat and vice grips is another option.

 

[Bud]

Vice grips or nut splitter if possible.

 

[Kestas]

One of the first expensive tool purchases I made 40 years ago was an oxy-acetylene kit chiefly for removing rusted bolts. It cost me a lot ($400), bought new in the pre-craigslist days. But it only made good sense, living in Michigan. I've had a lot of use from it. It saved me a lot of money by not having to take work to the shop.

 

[WyrTwister]

I have found , heat it as hot as you can get it , then spray with penetrating oil . I like PB Blaster .

Repeat as necessary . Seems like this helps get the oil into the little cracks and crevices .

Try to get it red hot .

You may have to sacrifice a socket . One that is small enough to have to hammer it on .

You may have already been suggested , the specialized socket that is designed for this task . that have cutting edges to " bite " into the nut .

Best of luck ,

 

[The motor guy]

Originally Posted By: JC1
I have the cheap nut splitter from Harbor Freight. Works OK for those rust exhaust nuts and bolts.


Don't tell the wife you have one of those. She might use it. Lol

 

[willbur]

I got a snap on splitter. Works great if you have good access to the bolts you need removed. Very bulky.

 

[anndel]

Vise Grips, Vampliers, bolt extractor, etc., would work.

 

[philipp10]

A simple angle grinder with an abrasive wheel will cut those bolts off in seconds. Less than $20 at Walmart.

 

[Fitter30]

dremel with a cut off wheel split the nut on a angle

 

[Merkava_4]

You need a Flank Drive Plus wrench.

 

[royesses]

Channellock 410 "Nutbusters" pliers if there is room. A good nut splitter also may work.

 

[spasm3]

kroil heat, more kroil. Let it sit and heat it again. Hammer on a smaller impact socket and have at it with the impact.

Maybe grind the head a bit and weld a nut on the rounded bolt.

 

[dlundblad]

I ended up just taking it in. One garage could get to it next week, but the one closest to my house said he'd get to it that night. Should get it back sometime today.

Appreciate all the advice guys.

 

[WyrTwister]

Best of luck to you ,

 

[zzyzzx]

Pipe Wrench:

Angle grinder:

And you should really own both of these already.

 

[dlundblad]

A grinder could have reached 4 of the 6 bolts. Maybe 5 with a small enough wheel, but it would have been close. Would have still had to take it in with probably no cost difference.

The mechanic said they were stainless and would not melt so he had to heat them up until red and use an air chisel to open them up. My luck I would have man handled it too much and broke the exhaust manifold in the process.

The downstream 02 sensor was destroyed. Oh well. $60 for everything and less than half of what I was quoted for at the other place. He used the cap that came with the cat for the non existent 02. RA here I come!

Someday, I shall have a cutting torch. Someday.