Late this spring I purchased a 2019 725DT6 with a rear discharge deck with 570 hours on it from a dealer. The mower was a trade that had come from a local municipal purchase. Usually these are taken care of well so I agreed to an as is purchase after testing it in their yard for a bit. Had a few issues that I have been able to resolve, but one that has been a problem since day 1 has me perplexed. The drive motors operate very quiet and as expected, until I get on long runs then make a turn. The motors get loud and start slipping on both sides after the turn until I move about 25 - 30 feet then it stabilizes and runs OK until the next turn. The expansion tank is about half full cold and about 3/4 to 7/8 hot, though it was low when I purchased it. These are self priming as I understand it so there should not be air in it anywhere. Though not required for another 400 hours I was going to change out the fluid and filter to be certain a dirty filter is not the problem, but before I do that thought I would ask the question here. Has anyone run into this problem before? Any ideas? Thanks.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
725DT6 Drive Motors
- Thread starter itim25
- Start date
More options
Export threadmechanic mark
Lawn Pro
- Joined
- Jul 15, 2013
- Threads
- 175
- Messages
- 7,413
Mark: Thanks for the reply. This is more for closure on this question in the event anyone else has the issue. Since my original post I have a couple things to report. First, I found that the hydro pump cooling fan hub was cracked. While the fan spun it did more slipping so was not cooling as it should. Replaced mid August. No help. The hydro drives were still loud and slipped after long runs. While I did read the post you sent I didn't believe there was any way what I was experiencing was normal, primarily due to the slippage, which made controlling it after turns almost impossible. Fast forward to last week. Performed some PM and decided to change the hydro fluid and filter. Completely resolved the issue and there is virtually no noise at all. Either the recommended 1000 hours change is unrealistic, or the broken fan and lack of cooling ruined the viscosity on the hydro fluid or the filter was plugged. Either way life is much better mowing my field.
Last edited: