Hi, guys
I was cleaning up the threads on my heat exchanger stud bolts in preparation of reinstalling the heat exchangers. I noticed one of the stud bolts has two of the threads stripped off about in the middle where the nut would be tightened to. All the rest look good. Should I try to replace that stud? If so how should I do it without breaking it off at the block? I am assuming that could turn ugly fast.
TIA

 

I would replace it, but like you said, it can turn ugly. You can double nut it and see if it will come out easy; even better would be to heat the area around the stud without getting the stud too hot, and then try to unscrew it. Worse scenario, you break the stud and will then have to drill it out using proper drill jig.
You can also put a nut on the end of the stud to protect it, and then tap it with a hammer, that will help to loosen up the threads.

 

Just a fast note. I have a 90 964 and after the clutch slave bottom stud broke off flush with the tranny I had the car taken to V Motors and they were able to use a easy out and got the broken stud out wthout even dropping the enginen and tranny. Saved a bunch on labor.
If it were me I would use all three methods double nut tappiing on the stud with a nut for protection and heating the base up. We use all three for taking out pipe and such. All good advice and methods..

 

IMO, the quickest approach is to buy the custom drill guide sold by "A Quiet Boom" over on Pelicanparts, cut the offending stud off flush with a Dremel and a fiber wheel and then drill the old stud out.