Wheel Horse 252-H hydro drive issue

[crazyoldtractor]

I just got a new old tractor from someone down the road this weekend. It is in very nice condition except for the hydro drive. The lever will not go al the way forward in the forward position. I will in the reverse though. So the tractor cant reach its max speed going forward because the lever wont go all the way forward. I looked at the mechanisms and stuff under the tractor and cant see what the problem is. I think it goes a bit faster in reverse than it does going forward even.

The tractor is a Wheel Horse 252-H with a Kawasaki FB460v engine.