4H problem

[markb5900]

Hey everyone,
I’m having an issue with my 1990 yj not going into 4H. It will go into 4L without an issue. When trying for 4H I just get grinding like the transfer case isn’t meshing. Can someone point me to where to start checking?
Thanks

 

[Gilaguy23]

New to you? Old to you and fine before? Lube check? You check the linkage? Body lift? molested and "made better" by PO?