stif gear on mercedes sprinter

Radsteral

I have had this for 4 years now almost .
when i got it was a bit suspicious about the gears that are mounted high upie with cables. vw lt van i had hasd the long gear stick right from the diferential so very easy to change but this one too has been exelent except the last 2 weeks where first and second gear went too stiff. A friend got the diesel version 208 cdi and few times i have used it i couldnt bear it due to gear needing to push hard