Hydro rebuild
 

I picked up a 2009 SLTX 1054 that looses torque after 10 minutes of running. The engine runs fine, the transmission looses pull anytime a load is introduced (traveling up hill, sharp turns). I have replaced the drive belt and all of the pulleys, changed the fluid in the hydrostatic transmission 2x, and still have the same issue. Any other suggestions before I pull the transmission and tear it apart? I'm guessing it is either filters, or the motor inside, or both. Anyone done a rebuild? Any ideas or words of wisdom are welcomed and appreciated.

If you have not changed the filter, I would do that first and just top of the fluid.

I do believe there is a method to bleed the air out of the Hydro would also try that
Download the manual and it will give you all the info
Oz

Have you seen this recall. http://apps.hydro-gear.com/Portal/Do...1_20120125.pdf
I think they may be newer models but you could check your transaxle numbers. I have one old Craftsman with a Hydrogear that would not pull up a bank at the road at odd times. I could pull up on the brake pedal ad it would start pulling again, The brake was not fully releasing at the axle. I'm sure you have checked the free wheel linkage to be sure it's not partially engaged. Hydrogear has PDF service manuals available to download if you can determine which manual is for your transaxle.
Cannon

Don't attempt to tear into it. You won't be able to get parts, and if you do, they will be $$$$. Cheaper to find a used rear than disassemble. Besides, if you have no experience with complex hydraulic components, you don't have any business inside a hydro. They aren't as easy as some guy on Youtube makes it look.

Check the drive pulley and make sure it isn't slipping on the shaft. Check the brake and the linkage to the unit. I've seen those cheap HG unit's break linkage that runs into the transaxle unit. Outside of that, toss it and get another. They are throw away units.

We replaced a hydrogear in a newer model Cadet about 10 years ago. The rear end actually had the hydrogear tag on it. I was able to order it for a LOT less than Cadet wanted. Don't even know what kind yours has in it, just throwing it out there that you might want to shop around some. If you do replace yours and get bored, open up your old one before you send it to the junkyard--its scary looking inside one of those things! Lots of really nice machine work on those parts!

my ltx1550 is doing the same thing... it has a new drive belt, new tensioner and pullies... i changed the trans oil and purged it...

you ever get it fixed or replace your trans...