Ford Lehman 120 Broken Exhaust Elbow Stud

You were lucky in that you had a nice amount of the broken stud left to work with.

Check out YouTube if it happens again, there is lots of good advice there.

pete

gonesailing13 said:

Just curious , why were you replacing the elbow ?

Click to expand...

I'm doing some maintenance to the engine, replacing the oil cooler and trans cooler and hoses, I took off the heat exchanger and took it to a rad shop to be cleaned and pressure tested. I took off the elbow to check it and found quite a bit of corrosion at the exhaust pipe joint and it was weeping a small amount of coolant at the joint to the manifold. The surface on the manifold seems good so I figure I'll change out the elbow now and know that it will be good for a long time.

Worn out?

gonesailing13 said:

Just curious , why were you replacing the elbow ?

Click to expand...

catalinajack said:

Worn out?

Click to expand...

Yes worn out.

An interesting thread. I learned a lot.

Jim

Another suggestion - occasionally, I do it every six months or so, back the bolts out a bit and retighten. No worries then about frozen mounting bolts. One could even apply new anti-seize once in awhile.

I’m all for the heat and penetrant of your choice as a primer but have had exceptional luck with 30 seconds of rat tat tat using a Sears cordless nail driver (palm nailer). For some reason the small repeated blows are an order of magnitude better than the old ball peen. I used vice grips starting with very small back and forth twists.

Clean, straight threads

Ttsaang said:

I was able to remove the stud today. It was a combination of PB Blaster, propane torch, wax and a stud extractor that I picked up from the parts store. I hit it with the PB, heated it for a long time and then touched the wax to the stud which sucked into the threads and slowly was able to move the stud back and forth with the extractor. Kept repeating this process with more movement each time and it eventually wound out.

Click to expand...

Run a clean tap into each hole, with some grease in the flutes to trap and lift out any garbage on the way out. Use Anti-Seize on fresh stud threads but be cautious of over-tightening as the anti-seize will lower torque readings.
Clean threads are important, along with fresh washers and nuts.

Glad you got that sucker out of there!! I had several break off in my aftercooler housing (Volvo Penta TAMD-41B)....unfortunately, steel studs broken off below flush, in an aluminum housing. That was NOT fun to fix!!

Someone above wrote that they took the whole manifold to the shop and the stud was heated cherry red. This (IMHO) is the whole story - you have to put concentrated heat onto the stud. MAP is not sufficient - it has to be oxy-acetylene. Furthermore, you dont need to remove the manifold - you just need to apply the right torch (oxy-acetylene) - the "mass" of the manifold is not an issue compared to concentrated the heating power of oxy-acetylene.

If necessary, multiple cycles of cherry red and cool down. I have not tried the wax application but this sounds like a nice trick.

Nick