Bicycle Mechanics - Headset Rookie

I installed a new headset on my old 1" threaded fork. The lock nut on top will not allow me to tighten down to the bottom nut (both on top of the fork, my description is abysmal). The resulting problem is that my fork is all over the place. When i apply the front break and push the bike forward and back there is play between the fork and frame. Is it better to cut threads off the top of the fork or is there a spacer that can bridge this gap. I know that on threadless headsets you use spacers but is this also the case for my threaded fork?

until this is fixed i continue to loose grease and it ends up on my shorts and my students mock my greasy crotch. please help.

stop mocking thee crotch of thee cyclists--- I think from your description that you need a simple 1 inch spacer ring( sometime notched as is the steerer) and a proper cinching of the race to the lock top nut--- the top nut can also be replace with one that has no lip--- thats my best guess--- teacher, teacher......

Yeah, you need to get some headset washers. These range from 2mm to 10mm. Measure the gap you have between the locknut and adjustable cup and get the next size up washer.

You also need TWO headset wenches to properly tighten a headset. You spin up the adjustable up into the locknut which you're spinning down with the 2nd wrench. The majority of headsets that have repeated loosening problems were not tighted in this manner.

Thanks for the support and the ideas on how to fix it. i will order the spacers and wrenches tomorrow. darn another reason to add to my fledgling tool collection. i will let you know how it turns out