Exhaust Rocker Cover Stud replacement

While trying to fix oil leak from the right cylinder rocker cover the rocker cover stud came out with the rocker nut. Actually the same thing happened when I checked the rocker clearances earlier in spring... When attempting to tighten up the cover the Rocker Nut popped off the stud revealing stripped outer end of stud and stripped rocker nut. I managed to unscrew the stud from the head. I'm certain the oil leak was from not being able to properly tighten down the nut but I now have a slightly bigger problem.

Rocker Stud - good thread was in the head


Exhaust Rocket Cover Stud by niagara850, on Flickr


Looking at Head Right Rocker. Whats with the stud threads? Looks like the stud was drilled out at some point, is that a Helicoil in there?


Exhaust Rocker Right Cylinder Cover off by niagara850, on Flickr

How do I fix? Is it a matter of ordering a new stud (NMT2252) and Rocker Nut (NMT2085) and threading it in? Do I have to do something special like put locktight on the head end of the stud to keep it from coming out the next time I remove the Rocker Cover? Thanks in advance.

Just order a new stud and fit it with some thread locking compound, it does look like it has a helicoil currently fitted, but that shouldn't pose any problems. while you have the rocker covers off you should check them on a flat surface for bowing, this often happens when they are over-tightened, the solution is to sand the face on a piece of emery paper on laid a flat surface. You could also check that the gasket you are using follows the contours of the rocker cover sealing edge, many gaskets have a large overhang which traps oil behind it and this will sometimes provoke a leak. The fix for this is to use a craft knife or a pair of scissors to trim off the excess.

That is a regular ¼"-20 thread, you can buy a tap at Canadian tire to clean up the threads. You can also use ¼"-20 stainless steel socket head cap screws to hold the rocker covers in place instead of the studs and nuts.

Jean

You can also get neoprene gaskets (or make your own) to put under those covers. They tend not to leak so much.

Dave
69S