HELP! coilover locking rings stuck

I had Eibach coilover on my Honda. After 6 years or so I can't adjust the ride. It drop all the way down. Learn my lesson on getting future coilover. Looking at your picture you might be screwed of the thread. Maybe a member here got the answer.

 

Try soaking with PB blaster. That stuff is miracle juice in getting things unstuck.

 

Are the rings of a dissimilar metal from the external thread they go on?

Again this is a lesson for those who are advocates against "rustproofing." and application of rustproofing or LPS 3 would have likely kept this from happening.

This happens all the time to parts that are "broken" by mechanics and are replaced at the owner's expense for both the part and the labor to remove and replace them.

PB Blaster, KROIL or any of the penetrating oils might work.

Heat is the next option, but you mail "boil" the oil.

If you apply too much force to a pin spanner, all you'd do is to deform the pin's hole.

The best solution for even the most stubborn locknut is a split collar with a threaded hole and pin to insert into the lock nut's pin recesses. This requires a mill and other machinery to make a custom one.

Then, you can use a copper or grass hammer to knock the collar back and forth to loosen the corrosion on the lock nuts.

If you can buy new lock nuts, a Dremel tool with an abrasive cutter can be sued to cut a slot into the lock nut to relieve the pressure caused by the corrosion, which expands to lock the components in place.

These are the steps that I would take and in that order.