2002 Mitsubishi Shogun when i drive for more than 30 mins at temp lights comes on and gearbox is clunking at propshaft

It would depend on what level of repair is required ,best thing is to get it checked by a professional as it could be a sensor issue,or sticking valve .I would not go condemning something until all repair avenues have been exhausted.you could even try flushing the box in case dirt in something or it may have a filter that can be replaced .Can you feel play on the out put shaft onto the prop shaft ?

Hi mste also it is stuck in 3rd gear gearbox gone into limp mode iv read still drives jus slow pulling off i just want car how it shud be

Are there no other codes stored to give a clue as to the cause ,And is the oil level and quality okay ?I know the fluid can be expensive but it,s maybe worth trying to flush the box out with some fluid change.Is the linkage okay it,s not seized.