broken stud... how to remove ?

[BobCT]

Guys, I removed my exhaust in preparation to replace the center link
and guibo this week. The first stud broke in half (the rest came out ok).
I have about 1/2 the stud left. What's the best way to try and get the rest out. Also, should I replace the exhaust gaskets ? They look ok but I'm not sure.

thanks,
Bob

[Wayne@PelicanParts]

Always use new gaskets - just because they look okay, doesn't mean they will seal correctly:

http://www.pelicanparts.com/BMW/catalog/shopcart/BE36/POR_BE36_exhaus_pg2.htm#item9

Where is the broken stud?

-Wayne

[BobCT]

of the two pipes. Can I get away w/o it ? There's enough stud left to keep it
locked in side to side but that's about it. I have pretty good access to it if I can figure out a way to replace it.

[BobCT]

of the two pipes. Can I get away w/o it ? There's enough stud left to keep it
locked in side to side but nothing to thread onto. I have pretty good access to it if I can figure out a way to get it out and replace it.

[OilStain]

Do NOT use an easy-out type puller.
When they break, you have a real mess on your hands. Trust me.
Heat, PBblaster (supposedly), extreme cold, a welder, a reverse (left handed) set of drill bits. Any of these would be better than using an easy-out.

Try doing a search out on the net for ways to extract a broken bolt.

I may do a write up on my experience with the easy-out eventually.

[Jam Boy]

If you run out of options, you can use a hacksaw to saw a slot into the remaining stud.

Then, use a slotted screwdriver to back the stud out...

[bimmer95]

Heat that entire corner of the manifold RED hot with a torch then back the stud out with vice grips. Takes a while, but it works.

[choffa]

Yes, you must replace the stud, you're guaranteed to have a leak if you leave it in.

If you have enough of the old stud exposed to get a pair of vice grips firmly on it, you are ahead of the game. THey usually break off flush with the flange requiring a screw extractor (as above, these can present a bigger problem if they break off). Soak the stud over night, from both sides with penetrating oil. Then heat the manifold as hot as you can, quickly so the manifold expands more than the stud. A MAPP torch is preferable to propane, even better is oxy-acetylene. Be careful not to burn anything adjacent to your work area,and be aware that the penetrating oil may ignite. Garden hose close by.

Grab it with the vice grips (a new pair with sharp teeth) & squeeze them as tight as possible. Hopefully it will spin out without much problem. Rock it back & forth if it is still reluctant.

If it won't budge you have several options. First grind it flush with the manifold flange (Dremel cut off wheel). Then center punch it dead center. At this point there are several tools to help, the easy-out (tepered left hand spiral) is an old timer that if used properly can work. Again penetrating oil & heat as you use it will help. Use the largest easy out you can fit, the smaller they are the easir they break. Don't go bananas on these, if they break, you're hosed, they are impossible to drill out (hardened steel), and are best burned out. Theyre are several variations on the easy out idea, a good parts store should cary them (NAPA).

Also mentioned is the left handed drill, available at Eastwood online, or through a good industrial supply house (McMaster Carr). As you get close to the thread diameter, often the old stud will spin out. Clean threads with a tap.

Another alternative and the best in my opinion is to drill out the old stud and tap the hole for new threads. Accuracy on the center punching & drilling is ctitical here. Be sure to punch the center of the stud & drill straight through the axis of the hole. Use the correct size bit for the tap needed. Often the old stud will break up & fall out as you drill, the tap will only clean up your original threads. Again, accuracy is paramount in the drilling, if you go off center, or cock-eyed, you'll get part of the old threads & part of new threads, not a good situation. If you bugger up the threads, you can use a heli-coil to restore the threads to the correct size.

On reassembly, use never-sieze on all studs, nuts. It will simplify removal in the future.

Good luck,

CJH
1996 328is

[BobCT]

tackle it today.

Bob