The car keep overheating, there is water in the radiator and the resevior tank 2000 jeep grand cherokee i check the oil their is no water found in the oil the water from both unit stays full

Radiator cap,Thermostat, water pump, blocked or corroded radiator or heater core.

it is probably not gearbox oil. it is probably transmission fluid because it travels through the radiator cooling tanks. the cooling tanks may have a leak causeing the fluids to leak into the radiator.

Is the fan working properly? Is the radiator flowing correctly? Does the rad cap hold the proper pressure?

You need to do a compression check on #5. You could have blown the head gasket again.

Since you have already changed everything that you have, I can not think of anything new that might cause your Jeep to overheat. Are you going by the meter in your vehicle or doing separate temperature measurements? I had a defective temperature gauge that caused me to chase my tail till I did separate measurements.

The reason for that may be that when its running it holds enough pressure to withold the leak momentarily. The main places where it could be leaking from is upper or lower radiator hoses, water pump, radiator, resevior tank or through you'r head gaskets. If you have the time, take it to a mechanic and have him pressure test it to see where the leak is coming from exatcly. Runing the engine with a leak, increases the chance of it overheating, which could cause internal engine damage.

Hope this Helps!

2 things.
Are the electric fans coming on?
You have a water flow problem.Either engine or radiator.These are the 1st 2 things to look at.
Barring head gasket problems(which is unlikely)I would get these things checked by a GOOD radiator cooling specialist.
Hope this helps

CHECK YOUR OIL. IF THERE IS WHITE STUFF IN IT THAT WHITE STUFF IS WATER, AND YOU HAVE A BLOWN HEAD GASKET OR A BLOWN INTAKE GASKET. EITHER WAY IT MEANS TEARING DOWN THE TOP HALF OF THE MOTOR. ALSO, IT CAN BE THE WATER PUMP, IF THERE IS NOT ANY WATER IN YOUR OIL. OR YOUR RADIATOR IS CLOGGED.

check coolant level check fan ,fan clutch(if elect fan sensor and proper function) ,belt for correct tension water pump -thermostat proper function,clogging radiator ,debris covering radiator

first, check that your oil level is full. Though it should not cause an overheat, oil does serve as part of the cooling system... Changing the oil should not have much to do with an overheating problem unless inadvertently the radiator, a hose or the cooling fans got damaged. Carefully check everything for leaks, make sure the cooling fans come on when hot.
After checking those things you will need to check the thermostat and the radiator for proper operation. If you do not have a blown head gasket one of these items are causing your problem. Before you ask...the water pump will work even when the seals are leaking or the shaft bearings are bad. If either of those two conditions exist the pump should be changed, otherwise it is not causing your problem.