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?

 

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

 

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.

 

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.

 

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

 

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

Helicoil. You can stay uniform on your stud sizes.

 

What size helicoil to stay stock with the studs?

 

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!

 

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.

 

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.