I'm having a hydro issue on my 6620 titan II also. My ground speed slows way down when on a grade, especially on the road. JD service guy put in a new forward relief valve (after much pressure testing). I'm gonna have to have him come back out and put some more shims in it though to bring it all the way back to normal.. He did tell me that he'd been working on Deere's for 18 years and only had to replace 1 hydro. That was a new machine and the hydro was factory defective.
How did yours act before it was replaced before?
Mark
How did yours act before it was replaced before?
Mark