AMZ66XT drive speed issue

I have a Groves AMZ 66XT Manlift that functions fine with the exception of the drive speed. It moves at about 1/5 of the speed that it should, in both forward and reverse. The machine Is hydraulic drive, with a drive motor for each wheel. I’ve jacked the unit off the ground and each wheel turns at about the same speed in both forward and reverse. It has a low and high speed setting. The wheels only move in high speed. While it seems strange, increasing the engine speed, actually slows down...

AMZ66XT drive speed issue

AMZ66XT drive speed issue