Trouble Removing Cat Bolts

[arbita1]

I'm in the middle of removing my cat to replace it with a premuffler.

Three of the 9 bolts came off easily. Three more I was able to grind off.

Now I still have three that are troubling me. The top inside one on the muffler/cat flange. And the two top inside ones on the heat exchanger flange. I can't fit the impact wrench or the grinder there. And the dremel just keeps breaking disks.

What do I do?

[Targa Me]

I did this same job on my 84 Carrera. its wasn't easy. For me, 4 bolts threaded off easily the rest of the I had to grind off. The nuts and bolts are not threaded into the muffler or CAT so if you can grind off either the nut or head of the bolt you can push the rest of the bolt off using a hammer and punch. Removing the CAT took me 6 hours and that was an air compressor and grinder. I know how frustration can set in so what I did was take one bolt at a time and continued on the one bolt until it was removed. (verses skipping around from bolt to bolt just to see if one's easier than the other.)
Good luck to you, be patient and persistant.

[Targa Me]

One other thing... because I couldn't fit the grinder in some areas, completely, I just ground off what ever i could of the troublesome bolt then chisled the rest off.

[JWLindsey]

Had the same problem on my '87 3.2 but got luckier with 5 coming off under their own power and one snapped bolt. The other three were just the ones you are dealing with and I used an air chisel and punch to blast them out of there. Wasn't too expensive to buy at Sears but do make sure to wear gloves, ear protection, and glasses as stuff tends to happen quickly when you resort to such implements of wanton destruction.

Good luck!

-JWL

[pete3799]

Smoke wrench is the way to go.
Going to be tough with out one.
Some of mine were even hard to get to with the torch.

[mthomas58]

Been there, done that. I assume these are the ones giving you trouble. I had to remove the lower shock bolt to move the shock out of the way and picked up these air tools from Lowes. Took a while, tight angles but did the trick.









Done

[KNS]

I had the same problem with my SC. I ended up having to dremel many of them off, cutting at strange angles to get to them.

This is when I came to appreciate my Arizona 84 Carrera. Having lived it's whole life in dry country, all my Cat bolts came off easily with two 13mm hand tools. No heat, no cutting, no cussing, no violence, just a little liquid wrench. The nuts and bolts were in such good shape I reused them for the premuffler.

[JeffO]

Use a dremel withe the one inch cutoff discs. I cut mine thru the center of the stud slicing the nut in half. Less then ten seconds per bolt and nut

[arbita1]

Finally got them off. I used a dremel to slice the nut and shaft. Then I used a cold chisel and hammer to beat it off. Each one took a little time to remove, but they came off.

I installed the fabspeed premuffller pretty quickly. I started the car just to check. Sounds a bit deeper. I'll have to go for a test drive later.

Thanks for the help.

[DG624]

DId you destroy the CAT? I want to reuse the CAT.

[arbita1]

Originally Posted by DG624

DId you destroy the CAT? I want to reuse the CAT.

No. I was careful to only concentrate on cutting/hammering the nuts and bolts and not the CAT. I may have given it a slight knick here and there but nothing that would prevent it from being used again.

[yelcab1]

re-inforced cut off wheel for the dremmel tool. The ceramic ones just break off.

[arbita1]

Originally Posted by yelcab1

re-inforced cut off wheel for the dremmel tool. The ceramic ones just break off.

They both break off quickly. But yes, the reinforced ones are slightly better. I went through a lot of them when I was doing this job.

[rusnak]

I would use an air chisel if the nuts are too far gone. Otherwise, just break the bolt in two with your wrench.

[Jesse16]

Too late now for you but this technique which I picked up off the forum worked on all but one or two of mine. After a day or so of penetrant soaking. With a good wrench on both sides, turn carefully in the tightening direction first. On each of mine I heard a distinct snap or pop or creak which I guess is the rust breaking. Then I loosened each one right off. Amazing.

[arbita1]

Originally Posted by Jesse16

Too late now for you but this technique which I picked up off the forum worked on all but one or two of mine. After a day or so of penetrant soaking. With a good wrench on both sides, turn carefully in the tightening direction first. On each of mine I heard a distinct snap or pop or creak which I guess is the rust breaking. Then I loosened each one right off. Amazing.

Not too late. I'll be trying that technique when I'm removing my heat exchangers in about a month.

[rusnak]

^whoa. Then I'd probably practice using heat. This will let you judge by color how soft the metal is. Too soft, and you'll damage the stud. Too hard, and the nut won't come off. Heat the nut until it is red, then use a gentle but sort of quick twist to get the nut to come off. There should be no damage to either the nut or the bolt.

[arbita1]

Originally Posted by rusnak

^whoa. Then I'd probably practice using heat. This will let you judge by color how soft the metal is. Too soft, and you'll damage the stud. Too hard, and the nut won't come off. Heat the nut until it is red, then use a gentle but sort of quick twist to get the nut to come off. There should be no damage to either the nut or the bolt.

Yes. Plenty of PB Blaster prior to and then heat. Maybe I'll be lucky and they'll just come right off with no problem.

[yelcab1]

When I did this for a pelican member, I told him to

1) buy a box of replacment nuts and bolts, stainless
2) He showed up at 5PM.
3) I removed 6, cut off with the dremmel tool the other 3 nuts (did not lose one cut off wheel)
4) replaced the cat with bypass pipe
5) had him back on the road by 6:30PM.

He bought me and my wife dinner the next week, nice guy.

[p911dad]