Ian K said...
Been using that repair for two seasons using the one gauge smaller o-ring. Works well, easy to adjust and to twist the lock. But have had to replace them once, it's a tough job for an O ring, so I'll try your heavier duty ones.
Easty will love this answer.
They are Caterpillar O rings.

Due to Contamination Control restrictions we have at work, we cant keep any "spares" that are not packaged in our Spec shops.
These are some of the ones they disposed of a while back just before an official audit

I have just changed them in case of deterioration in salt water.

a few weeks back