The top pivot (the one with the hole in it at the top of the image) on my Deore LX rear mech is sticking resulting in a loss of tension and chain jumping when I shift off the granny ring.

Squirted it with all sorts and the bugger still sticks.

Am I wasting my time with a sealed unit or do I just need to keep squirting until something gets in and frees it up?

Can you not dismantle it? A circlip on the back holding it all together?

Maybe it’s time for a new one.

Yep needs stripped and serviced. NIghtmare the first time…gets easier.

You can (as others have mentioned) take the circlip off and service inside that bit – but if your mech’s pivots have started to go sloppy and the jockey wheels are worn it might be worth just investing in a new one

5mm allen key in a vice will effectively act as a 3rd hand when re-assembling, makes the job much easier.

Update.

Soaking it with a cocktail of GT85 and Finishline wet lube for 20 odd hours seems to have freed it up.

Allen keys back in the box.