the exhaust manifold studs on the underside of the head...should I use loctite to keep them seated in the head? if so purple, blue or red (light, med, strong)

I just use a new lock washer and gasket when I do those. I've never had one back out.

Correct me if I am wrong here on this one, but this really not a good idea, it will make it nearly impossible to get out later. 

 

Not needed.

Why would you want to take them out later? I use Loctite green Sleeve Locker. They will not come out on their own. If you have to remove them for .... ???, heat them up with a torch and they will spin out. Are they loose and spinning or do the nuts seem to keep coming loose? If it's just the nuts coming loose, the threads may be pulling out. If that is the case, it's Helicoil time. +1 on the lock washer.... Always....

They stay in on their own if you just use a lock washer. I actually usually put a dab of anti-seize on mine so they WILL come out at some later point. Say I drive over a rock and destroy my header, need to remove the cat, have a rusty exhaust system. Need to pull the drive line, replace the oil pan. I dunno, I can think of numerous reasons to remove an exhaust manifold.

Make it easier for yourself next time and anti-seize them.

Edited January 15, 201412 yr by 987687

Really the only thing you should use on exhaust fasteners is anti seize. The heat cycling will beak down most anaerobic adhesives. The same goes for split type lock washers. A well seated stud with a flat washer and a torque prevailing nut (the kind with the pinched threads at the top) has held the exhaust on all my roos for many years.

-Adam-

I'm not worried about the nut...just the end of the stud that screws into the head.

Anaerobic thread lockers are not designed to take the heat of an exhaust system.  The green colored sleeve locker will set up and hold a stud, but it gets 'cooked'. If I remember correctly, the 'green' loctite is heated up to 600--700 degrees to break it loose for removal. In your heads, the anaerobic threadlockers will cook to a crystallized form that fills the gap between the male and female threads.

 

If you have thread problems then you will have to install thread inserts.

 

I use a ceramic based anti-seize that is good to at least 2,000 degrees. 

Some of you are misunderstanding his question for some reason. It plainly states he is referring to the STUDS and where they thread into the HEADS. 

 

I used the red threadlock on mine and have only put a few hundred miles on it. Then I used the blue threadlock for the nuts. The lockwashers I found wouldn't fit between the exhaust and the stud itself so that's what I did. I'll report back on how it holds up.

Some of you are misunderstanding his question for some reason. It plainly states he is referring to the STUDS and where they thread into the HEADS.

 

That's exactly what I'm talking about. If I ever want to get them out of the head again, I want it to happen peacefully without taking the threads. If the stud rusts and needs to be replaced next time I remove the header, I don't want to fight getting the stud out of the head because I glued it in two years ago. I'm not sure what you're talking about with the lock/spring washers. You put the studs in, put the gasket on, put the header on, THEN you put the lock washers between the nut and the header flange. You don't put anything but the gasket up against the head. Maybe you're misunderstanding how it works?

I never put nothin on mine. No lockwashers, just always used the oem stainless hardware. Yes, sometimes the studs come out when they get rusty, just double nut, separate, clean up and re-seat in the head. Some good anti-seize probably would be a good idea

I always try to replace a stid if it comes out, using one with a 'torque prevailing nut' so that the stud can torque up. Otherwise, you can torque the nut up to the exhaust flange, but if the stud itself is not torqued to it's own bore, it will eventually loosen up from expansion and vibration.

 

If a new stud is not avilable, i will torque the stud using the double nut method.

 

I am not a fan of using bolts as they seem to not hold torque, don't bottom out or bottom out too soon, or rip out the threads when torquing.

 

These methods i have resorted to after experiencing failures by other techniques, learning the hard way trial and error.

Edited January 23, 201412 yr by MilesFox

That's exactly what I'm talking about. If I ever want to get them out of the head again, I want it to happen peacefully without taking the threads. If the stud rusts and needs to be replaced next time I remove the header, I don't want to fight getting the stud out of the head because I glued it in two years ago. I'm not sure what you're talking about with the lock/spring washers. You put the studs in, put the gasket on, put the header on, THEN you put the lock washers between the nut and the header flange. You don't put anything but the gasket up against the head. Maybe you're misunderstanding how it works?

If it took 30 years for the originals to rust to the point they were not reusable, I would think it would be alright to glue 'em in there real good.... mine just keep on coming out and I've got the red thread locker on them. I used the double nut method but it's still no good. And if rust IS a concern, coating it in grease after installation should be just fine. And the reason I can't use a lock washer is because I drilled out the stud holes and re-threaded them about a year ago and used larger studs in place and there's no room between the stud and the exhaust shield to fit a lock washer.