i was trying to unscrew the damn nuts off the stud on the cat so i can install the sport muffler but they were so rusted it was impossible. eventually i broke one off completely. the stud broke in half with the nut still stuck on it. i know the other 3 are gonna do the same if i keep trying. how do i get rid of the broken stud? is there any possible way i can replace it or am i going to have to drill inside through the stud and just get a regular nut and bolt. how do i salvage the last 3. is there any way to loosen them up? i tried wd-40 and nothing helped.

 

Did you let them soak in a penetrating oil at all first

 

For the broken one.... you're going to have to do the drill it out just enough to be able to collapse the outer threaded part of the stud so that it can be removed. This is to save the threads in the CAT. New studs can be acquired from an Infiniti dealer.

For the others that haven't broken yet.... WD40 or some of the other penetrating products would be my 1st choice and let them soak for a while (hours) and repeated applications. There's another mixture that someone has mentioned before that they used, so hopefully they will chime in with that information. Also, if you can clean any of the exposed threads of the two remaining studs that the nuts will be threading off of with a wire brush (ideally with a Dremel and a wire wheel), that will help the keep them from binding as you attempt to remove them.

Good luck and I do feel your pain as I've been there and have done that.

 

its a 50/50 mixture of acetone and ATF

Regular WD-40 is not a penetrate (although they now make one under their brand)

PB-Blaster is a really good penetrant

you can also get replacement studs at places like autozone or lowes instead of the dealship

good luck!

 

Blnewt swears by the acetone/ATF mixture. Let it soak overnight.

 

thanks for the replies. i had actually tried to penetrants before and nothing seemed to work on those bolts and as for the broken stud, would i be able to just replace it with a nut and bolt or would that be a bad idea? what am i looking for when going autozone or lowed for studs? will is specifically say car stud or what?

 

theres actually 3 remaining studs... im not sure if i got it right when calling it a cat but its the part where the muffler attached to the rest of the car... theres two pipes that connect by bolting, and each pipe has 2 studs and 2 nuts on each. i think it might be called a flange. its a diamond shaped plate

 

Just take it to an exhaust shop

 

Remove all visible rust with a circular wire brush in a dremel. Then soak it with 50/50 A/ATF and tap the fastener with a wrench to make the vibrations drive the mixture into the joint. If that doesn't work then heat. If that doesn't work replace circular wire brush with cutoff wheel. Happy cutting.

I have used hot candle wax on warm/hot fasteners but they weren't rusted. It works great.

 

This is the bet advice at this point. If they're that corroded and rusted on, let an exhaust shop deal with it.