Stuck valve nut

[gnosez]

The last person who adjusted the valves had the 17mm hold down nuts so tight it took two of us, the special datsun tool and a 3 ft cheater bar to get all but one of them loose.

 

The last one (an intake valve) won't move and no matter how hard we try the wrench will slip before the nut does. We thought about heating the nut with a small pin-point flame or hitting it with a chisel.

 

This particular nut is also positioned right near a head bolt so you can't get a great purchase on it from a good angle.

 

Anyone have any good ideas??? Thanks in advance.

[AK-Z]

Hitting anything in the valve train is asking for trouble. heating it might work.

 

Try heating it up and using a electric drill with a socket bit, if you can get it in there,and set it so the drill slips on too much torque. On a duwalt drill I suggest 4 ot 5. The vibration from the drill slipping (the internal over toque mech, no the nut) should help loosen it. This is assuming you have th cam out.

 

Another suggestion is try tightening it slightly, just to get the nut moving, and then loosening.

[JMortensen]

I'd pop the rocker off and pull the whole adjuster out of the head and work on it in a vise.

[gnosez]

Thanks for both very good ideas. I don't have the cam out yet and hope not to have to but the idea of slipping the rocker off and then putting the box end of a 17mm wrench on it should do the trick (that and a 3 ft section of pipe).

[AK-Z]

just remember not to try to wrench it all at once. move the "pipe" in a rocking fashion. the rocking will sometimes help vibrate the nut loose and is less likely to shear or have the nut slip, messing up the catch points on the nut.

 

Oh and its a good idea to wrap the part being viced in something like a sock or a piece of cloths so you don't put vice marks on the part.