bad_brains

Against forum warning, when installing my new manifold I replaced all the exhaust studs. The installation went great, until the last stud! The bottom-left stud will tighten to a point and then skip back loose. Everything else took the recommended torque.



I got it as tight as I could, and called it done. No leaks. But I'm curious for future reference, what is the recommended fix for this: brazing in the hole and tapping it back to specs, or maybe tapping for a larger stud?

Anybody been there?

all_terrain17

Curious too, just noticed the stud I knew was stripped isn't even there anymore

bad_brains

My new manifold project was prompted by a blown manifold gasket, cracked manifold, and two missing studs!

Whoa whoa whoa! Easy there fellas. This truck became my problem post-damage.

Yota82

That is the most problematic stud. Drill and tap. I think Toyota should have redesigned the head in the 80's and put some steel sleves in ther or something. It's a common problem that needs to be addressed.

TC22RE

You may try a helicoil... Or tap for a larger bolt.

thook

JB Weld!!!! .......(I jest!)

Helicoil. You can stay uniform on your stud sizes.

bad_brains

What size helicoil to stay stock with the studs?

jp123

Same thing happened to me when installing my Downey headers. I bought a slightly longer bolt and it worked great. It's been about 2yrs with no problems.

The oem studs are quite shallow. There's probably ~ 1/4 inch worth of un-used threads in the hole.

Helicoil sounds like it would work great too, but it seems like it would be a bit tough to do it right without dropping the engine. It would work well as a last resort.

Good Luck!

thook

The next size up. A metric kit should have what you need. Check auto stores around you. It wouldn't be the easiest job, although it's not terribly difficult with the right tools. A right-angle drill, for example. But, try what jp123 suggested first. Just chase the threads of the stud port first with a used stud. Cut a groove (with a dremmel tool or thin cut off wheel) perpendicular to the threads all the way up the stud bolt (creating a channel), spray some PB Blaster on the stud/chaser, and work it in and out easy like to get and traces of rust and whatnot out.

all_terrain17

Retapped the threads (M10x1.25 if anyone needs the size), replaced the gasket and missing stud with a new bolt - no more annoying exhaust leak

Only torqued to probably half spec though for fear of stripping the hole again.