Lawn tractor - hydrostatic transmission...

[generator12]

I'm wondering if anyone has dealt with the issue of service life of one of these devices. I've got a Deere - Sabre lawn tractor with a Tuff-Torq K-55 hydrostatic trans, and it's been running fine for about ten years now.

Last fall though, just before winterizing the unit after mulching leaves, it began to "slip". The engine ran okay, but the trans was not grabbing reliably. I've since removed and drained it; then refilled with the recommended 5W-50 synthetic. (Factory equipped with straight 30 weight, but they now recommend the multi-vis.) It took about 1.75 liters rather than the 2 liters the factory states. Couldn't get any more into it.

After filling it I ran it around the yard a bit to get a feel for how it would go, and so far so good. But I'm a bit leery of what I'll have when it warms up.

Anyone have experience with these?

 

[FunInDuhSun]

Yeah, I have a JD STX38 hydro from 1994. It has the same trans as the Sabre.
Those are weak units. Over the years I've replaced it twice (with used ones)- and my lawn has no hills. The job is pretty easy if you're handy.
I've looked around the 'net but could never find anyone who rebuilds them, probably because it would cost too much.
The GOOD news is that there are plenty of them out there. I typically can find a whole tractor with a good trans for $300- 350.

 

[NYBo]

I had a Cub Cadet with a hydrostatic transmission that I got rid of a couple of years ago. I think the fluid and filter were changed maybe twice. It was purchased new. In 1968. It was still working perfectly.

 

[dingbat]

I have a 682 Hydro Cub (circa 1984) . The fluid (ATF) and filter has been changed once since I bought it in 1990. Still works perfectly

 

[gm280]

Actually I did change one on a Craftsman lawn mower because mine was slipping as well. However the new (actually used off EBay) one did the exact same thing. So I changed the belt and it fixed it. Yea a slipping belt was the real issue. So I just had to disassemble the older unit to see what makes it tick. Pretty simple setup. And I parted it out and made more money then I paid for it. So before replacing any hydrostatic drive unit make certain the drive belt isn't slipping first. JMHO!

 

[rbh]

Our JD 430d had a slipping issue, it turned out the bushings in the linkage were worn out, check for slack movement in the bushings (they add up) and replace. and change the filter if you have not done it yet.