Broken exhaust flange bolts

[WP77]

I'm getting ready to install a new 700R4 and 208 transfer case in my 87 V10. When I took the crossover exhaust pipe off, one bolt on each manifold broke off flush with the manifold. I've tried heating, drilling and easy outs to no avail. I'm not interested in trying to remove both exhaust manifolds, because I'm sure that will lead to even more broken bolts. I need to get this thing back running for my daughter since it's already been down 2 weeks. I'm guessing if I just use 2 bolts on each flange side I'll have leaks. Is there any type of hack, just to get by for a bit? I see those build your own flange kits. Does anyone know if those will work in conjunction with the factory flange? Maybe a way to add the 3rd bolt.

 

[Rickf]

If you are able to drill the old broken studs out, maybe use 1/4" nuts & bolts as replacement?

 

[PrairieDrifter]

Unfortunately there is no easy fix. Or "patch". It will leak if not fixed.

Heat and lube to get the bolts out. Weld a nut onto the broken stud and heat as well.

 

[WP77]

Unfortunately there is no easy fix. Or "patch". It will leak if not fixed.

Heat and lube to get the bolts out. Weld a nut onto the broken stud and heat as well.

They are both broken off flush with the manifold. No way to weld a nut on.

 

[PrairieDrifter]

They are both broken off flush with the manifold. No way to weld a nut on.

Yep have to pull the manifolds. Only way.

 

[MaicoDoug]

A center punch, and small & sharp "stubby" pilot drills work, then finally drill the tap size & tap. Works every time. Sorry to hear the broken bolts have caused a stop in progress. Happens more often than not, so....there are no gimmicks here, only basic skills. When the threads give out, weld the hole closed & start over. The part w/ the broken bolt may require the assembly to be removed, just the typical trail of bad stuff happening everywhere when short cuts become employed. Seems we never actually know that until late. I hope no grade 5 china hardware was used. If so at least the drill out will be easy. Easy outs are the hard way out, just my take. No broken bolt has EVER stopped me. Knock on wood. Exhaust systems are expected to break bolts. Soak w/ penetrating oil & heat, back & forth. Installation should always be prepared with a tap (H2 over sized tap), then non-aluminum anti-seize, then installation of the grade 8 hardware. -Never stainless, it's way too soft.

Hope to hear success soon!

 

[77Dmax]

I've welded several that were flush to the surface. It'll be difficult to do upside down though. With a good cobalt bit you should be able to drill it in about 15 minutes.

 

[Ricko1966]

Drill and tap. EZ outs you end up with an EZ out broken off making things worse 1/2 the time. Nikason clamp a stud if you just don't want to mess with drill and tap today. I'll try to find a pic of clamp a stud. BIAB. For the price I'd modify a Harbor frieght/ hardware store clamp. Wow! Just remembered once,I used a pair of vice grips as clamp once wrapped the handles in wire to prevent then from popping off. Worked for weeks,maybe months before I fixed it right.

 

[Edelbrock]

Pics of both mating surfaces?

 

[WP77]

I got them both out and saved the threads. Blew a hole with torch, bigger and bigger with drill bits, then retapped both. Threads are good enough to reuse.