You can try removing the adjuster knobs and soaking the metal piston with penetrating oil. The knobs arent really water proof on them and having the internals seize with rust is a problem with them. I've read that packing them with some grease helps prevent this, but I havent done it with mine. If you cant get them to work, call rancho and see if they will warranty them. They have lifetime warranty. If yours are the older style (non gas charged) there is a small charge to replace them with the upgraded ones (I think it was $8 each when I replaced my fronts).
Well I finally got around to getting the adjuster nobs to move.
-) Took off the plastic nob. Use lots of penetrant.
-) gasket was destroyed
-) cleaned piston cavity area with wire brush and a gallon of rust penetrant.
-) used Grey Ultra Silicone to make new gasket.
-) tapped adjust piston on shock with 1/2 rachet extension and hammer to get piston moving again. -) UPDATE 11/11/12. Do not use a rachet extension. Use a socket just big enough to fit in the hole. Tap gently.
you do not need much.
-) filled cavity with antiseze compound. (grey/silver looking stuff) The one that make your hands look like
the Tin Mans when you get some on your finger.
-) buttoned it back up.
-) adjusted to 9 then drove a block
-) adjusted to 1 then drove a block
-) went back and forth from 9 to 1 a few times and the shocks now work again.
Why wasent this portion of the shock made from stainless steel?