Help! Cross-threaded locknut on valve adjusting screw...
 

Oh man...

So I was doing my first valve adjustment on my '86 -- all the valves are tight, so I'm guessing it had been a while.

With one of the rocker arms, I was having a really hard time getting the locknut to loosen from the adjuster screw.

And then, looking closer, I realized that the locknut, improbably, is cross-threaded -- noticeably cockeyed and super-difficult to budge. How the hell the PO's mechanic did that, I have no idea.

What are my options from here?

I was thinking of getting a nut splitter, popping the locknut off, and hoping that the threads aren't too trashed to reuse -- maybe chase it with a die.

Otherwise...I'm guessing I need to drop the engine, take off the heads, the cams, and replace that one stupid screw?

Hey, I may have posted this in the wrong forum...mods, please move if this belongs more in the general 911 tech forum!

No not @ all you are in the right place,IMO I would reset it and see if it holds torque when retightened,if so leave it once you have correct clearance,after all you can't simply just replace it :(:( .
I can't for the live of me understand how someone could do this to start with,good luck.

If you pull the rocker and remove the adjuster CCW, the foot will pop off and you can remove the complete adjuster.
I have salvaged adjusters on the shelf, PM an address, I'll stick it in the mail
Bruce

See, that's the thing...the valve's too tight and I need to back out the adjuster...but I can't lock it in place...

I don't get it either. All I can think of is that someone just cranked way too tight on the nut, causing threads to deform.

Wait, so the little foot actually pops off when you back out the adjusting screw all the way? The engine is still in the car (sorry, wrong board?). Is this something I can do without pulling the rocker?

If that's the case, that would be wonderful.

If that lock nut is cross threaded, you want to remove
the rocker shaft so you can get at the rocker. It's not
a big deal, but the rocker shaft may be stuck. If it is,
I'd try some heat and PB blaster to get it loosened up.
Patience is the name of the game here.

Don't pound on it as you'll score the bore that the rocker
arm shaft is in, and then you'll possibly have a leak.

Getting the rocker arm out was a huge PITA that eventually involved drilling, but I got it out finally. Bruce was awesome, thanks for the adjuster screw!

Used a Dremel to grind the foot off of the old screw so as not to force the bad threads through the rocker shaft. Replacement screw and new nut and I was ready to go.

Incidentally, has anyone noticed that the new adjuster screw nuts you can buy seem to be made of softer metal than the old ones?

Key point to take away -- be careful with the adjuster screw threads and DON'T cross-thread the old nuts! Not that anyone here needs reminding, but I wish my car's DPO (dip**** previous owner) had kept this in mind...