Outer Limits 4x4 Board

i pulled the transfer case apart again and found that the person who pulled it apart before me had forgotten to put a cir-clip back in front of the bearing holding in the front output shaft,will get a new one and see if that fixes the problem

i replaced it and took it for another drive.i got further up the hill but then the same thing has happened,the bearing has been pushed forward and it wont go into 4wd

i jacked the engine up and the passenger side engine mount has come apart,just bought a new one and about to fit it

we pulled the transfer case apart and replaced bearings and seals and it did it straight away again,mine says only 270,000 kays on it but i don't know how true that would be.
i will get under it today and check all the mounts to see if that is the problem

When i start going up a steep hill in 4wd the front output shaft in the transfer case gets pushed forward, this pushes the bearing forward and knocks out the oil seal and starts to leak. it pops out of 4wd and then i cant get it back in. Would anyone know why this would be?