rb presilencer fix
 

I just got a rb full single exhaust from a friend and i went to put it on yesterday but the threads on the header end of the presilncer were messed up - long story short: one of the studs snaped off. Does anyone know about the construction of these things, cause they aren't screw-in studs so I figure they are just bolts welded on the inside. Im not sure what i could do to fix it, any suggestions?

Cody

Give Racing Beat a call (714) 779-8677 or e-mail them. Racingbeat.com

Maybe they could offer some help on getting it fixed?
It's likely not the first time it's happened.

Good luck.

I've seen this problem many times before. The threads on Racingbeats single presilencer (from the short primary system) tend to disintegrate after a few years. To fix it, cut what's left of the stud off, then grind it down flat. Next drill out a new hole where the stud used to be, and weld a new one on. If you keep your welding to a minimum, the header bracket holes will be just large enough to fit over the welds.

Its not the easiest fix in the world, but it beats buying a new presilencer!

This also just happened to me. I was changing my clutch and took the Racing beat pre-silencer down and one of the studs snapped. Problem is they are welded in so I couldnt get it out easily. I was gonna drill it out and tap it, but I think they are hardened studs and the tap might break. I just left it for now and will probably weld the silencer and header together for no exhaust leak.

-jrx13

I cut off what was left of the rusted, stripped, mangled studs on my presilencer and welded on a small pipe "extension" to that end with a matching flange on the end, then bolted that flange up to the header with the standard header gasket. No leaks, issues, etc. in 3-4 years.

Always use anti-seize and if prior owner didnt do that, soak then rusty bolts with wd-40 or similar. And dont use a 12-point socket.

Those studs are a total PITA to drill out. Very hard metal. Your best bet is to grind it flat and take it to an exhaust shop and have a new stud welded on then grind the surface smooth.

There is a better way. Open presilencer surgery. Cut open the shell so you gain access to the back side of the stud. Then cut down through the 3/8" plate to get rid of the stud remnant. Then set a new bolt of the same length and thread pitch in place and weld it in. Add the small piece of steel you cut out of the 3/8" plate and weld it back in. Reinstall the section of shell you removed. Once it is all welded, grind any lumpy areas smooth on the flange surface so it seals again.

This is the way I fixed a broken presilecer stud and it worked out great.

Easie to just weld the pipe to the presilencer plus a flange.