Here is a photo of an exhaust manifold stud which I removed.

 

There is aluminum stuck to about five turns of the thread, at the end.

 

What should I replace the studs with? The pitch is m10 1.25.

 

Should I tap the holes at 1.25, or drill them out and go larger?

 

Mkoch

Don't see your picture. What I did when I had this trouble with my Brat was step up to 7/16 SAE. Get the SAE stud and matching tap. No drilling required. Just tap out existing stud hole. 

1.

1. Like he just said The 7/16” stud swap is amazingly simple. Buy the studs, nuts, and tap and a bottoming tap.

As he said - Tap it out and install new studs with no drilling.

Could probably get away without the bottoming tap

 

2. Helicoil or timesert thread repair kits. Pricey and have to drill but otherwise easy and solid.

 

3. attempt to clean and chase the threads and the stud and hope for the best. Probably a waste of time and not worth the time unless you’re really timid of anything else.

That much aluminum on the threads, probably stripped, not enough to nothing left to hold.

I have used heli coils several times, no problem for this.

Here is the image!

 

Very common. All subarus for decades, every model, every engine, use the same stud threads so the approach has been the same for decades and thousands and thousands of subarus. Helicoil/timesert or do the cheaper/easier no drill 7/16” repair, theres a detailed thread about it, go there.

Edited December 19, 20178 yr by idosubaru

Heli-coil. If you have ASV spacers just install a standard 15mm long heli-coil and leave the tang on it. Go to the dealer and get exhaust studs for 2000 Legacy. Let them stop on the tang. If you have no ASV spacers then heli-coil the cylinder head as you would any other thread repair.

 

www.threadtoolsupply.com

 

GD