Jeep Repair: oil filler cap, jeep cherokee xj, oil filler cap

Question
I have a Jeep Cherokee xj sports 2000 6cyl 4litre.
My oil cap will not unscrew from the rocker cover.It just spins/turns either way without undoing itself from the cover.
It used to make a rachet type noise previously when turned.Now it is silent when turned.
Do I need to buy another cover and oil cap to replace the above.
Greatly appreciate your advice on this frustrating situation.
Best regards
Paul McDonough
Murwillumbah New South Wales Australia

Answer
The ratchet device in the oil fill cap, which prevents over-tightening, has failed. The only part you need to replace would be the oil cap. To remove the old one, pop the upper part of the cap off the valve cover then with a large pair of pliers unscrew the rest of the cap.