cjjones

In preparing for my new sharkwerks exhaust, I took off the center muffler this afternoon. However, on the passenger side where the center muffler bolts to the cat I broke a bolt while loosening the nut as you will see in the picture. Yes I used penetrating oil. Yes I worked the nut back and forth. I tried using a punch (as gently as I could) to get it out but had no luck. The head of the bolt is round which makes me think that the hole where the bolt goes through on the cat is threaded.

Anyone know if it's threaded or not? Thanks.

extanker

make sure the stud is not welded .i would try to use a torch and heat up the area around the broken bolt then drive it out. i do not believe it is threaded...just pressed in [splind]

Canyonrs4

I too am fairly certain it presses in, just to be sure your can double nut one of the unbroken ones and see it it turns out...

cjjones

It is a splined bolt. I'll try taking a torch to it tomorrow and see if I can punch it out. Now I have to find a replacement bolt....not too common obviously. Thanks for the responses.

Cbst09

I have had this happen before, use a small 1/8" metal drill bit and drill into the broken stud about 3/4 of an inch. Then use a punch and drive out the pressed in stud.

cjjones

What did your replace the stud with? I know it's an M8 bolt.

extanker

nut and bolt it. if ya cant get metric use 3/8

Cbst09

I had mine break on the center muffler part and used a m8 hex bolt. No reason you couldn't use a hex bolt. While I was at it I replaced all the nuts with new ones, you can find the nuts at Home Depot in the hardware section. They are tapered slightly on one end to make them lock. This is not to be confused with the locking style nuts that have a nylon insert, those would clearly melt in an exhaust application. Also, a little graphite lube when reinstalling is not a bad idea to make removal easier down the road. Good luck with the fix.

Cbst09

if you want to get a pressed in stud then you could get one at any muffler shop

Edgy01

This is where having a torch and a 4-1/2 grinding wheel helps!

semicycler

Drill it out. Start with a bit roughly 1/3rd the diameter. Then keep re-drilling the hole with increasing bit diameters until the broken bolt is out.

cool flash

Porsche sells that bolt as well. I picked a couple of those up when I got ready to do my spark plugs.

It's just a regular M8 bolt of certain length. I've even seen those at home depot and such.

L

spiderv6

I wouldn't buy the bolts from Home Depot. My recent experience of their bolts for other uses are that they are made in China VERY cheaply and snap in the wind.

JJF3

If you do go to Home Depot or the hardware store, just make sure the bolt is graded.
Grade 5 should be sufficient, grade 8 is stronger. Steel Socket head or Allen head bolts are even stronger equivalent to like a grade 10.
If it is graded, it has to reach a minimum standard rating no matter where it is made.
JJF3

mattyf

If it's pressed in, I would try and cobble something together using a C clamp with a socket such taped to the one end so that the stud can be squeezed out the backside.