hello, im having problems on my 1990 xj with 181k miles its 4x4, got it about two months ago it started shifting hard and moving from high to low and low to high for no reason while cruising, got worse after i cleaned the engine compartment with a degreaser and water now it doesnt shift till its going at least 30 then again at around 50 and i think its running rpms high so its overheating. any help?
thanks.

 

Did you check the fluid level? I would start there.