XT1 LT 46 losing power

[andrewnelles]

Hi,

I have a Cub Cadet XT1 LT46, 4 years old, 60 hours on the engine. It's developed an issue where it loses much of it's power and struggles, or even fails, to move when there is even a slight incline. It runs mostly normal on flat surfaces. The problem gets worse as it warms up. There is an audible whining sound from the transaxle when it struggles. The engine seems to be running normally, no issues with blade speed, etc. when the problem is occurring.

I'm guessing this is related to the hydro transaxle. No visible fluid leaks or damage that I can see. Fluid level is normal, and the color of the fluid looks new.

The transmission is a Tuff Torq K46, part number 7A646084591. 60 hrs seems really early for a failure...

Any suggestions on troubleshooting to pin down the exact issue here?

Thanks.

[Carverlvr]

See my post about the K46. Since I’m guessing you’re out of warranty, I’d pull the whole transmission, pop off the flat fill cap, inspect and clean the magnet, dump the factory 10w-30 and refill with the Tuff Tek synthetic. While it’s out, make sure to give the whole unit a good cleaning. I’ve read a lot of threads where doing this has revived many a K46. I changed mine (xt2 with K46) when I bought it used at 80 hours and just added a temp gauge to monitor. Hope this helps.

[andrewnelles]

Yeah, I'm concerned if this is a failing K46, a fluid swap might just be a band-aid on a larger problem. Since the fluid level and condition seems ok.

How involved is removing the transaxle and reinstalling? Few hours?

[Carverlvr]

Remove and reinstall the first time was about an hour each which included the deck. Make sure you have a good set of snap ring pliers, and I recommend having a new fill cap and the oil ready to go. Next time I do it I bet it takes half the time. Also allow an hour in between to drain the oil. I left the wheels on for mine but that probably just complicated it.

[andrewnelles]

I pulled it, and drained the fluid. It was in worse shape than it looked. The old oil was very dark, and as I emptied the drain pan the last little bit had a fair amount of glittery metal in it. No magnet in the plug as some seem to have.

I'm thinking a replace/rebuild is in order, not sure new fluid will save this one.

[Carverlvr]

I’ve read posts where their k46 wouldn’t even move anymore and a fluid change bought a couple years more service and back to original (if not even stronger) performance. Certainly doesn’t hurt to try. My next fluid change will involve taking the case apart to clean both magnets and replace the filter. Btw, I’ve seen a magnet upgrade/add kit for ones that don’t have the top magnet. Make sure your looking under/filling with the flat cap, not the thumb screw looking vent cap.

[andrewnelles]

I'll give it a try before I order a new K46.

I found some threads where synthetic 20W-50 was mentioned as helping out some stubborn units. 3qt of that is cheap enough to gamble on.

[andrewnelles]

Update: Surplus Center had a new K46 for under $400, so I just did a swap. Mower is behaving like new again. I'll save the faulty K46 for a future rebuild project, and worry about it another day.

I did fill the new K46 with Mobil1 synthetic 5W-50 based on some previous threads.

[Carverlvr]

That’s a great price! Actually less than the full rebuild kits.