TuffTorq K46 Repair Guide with Pictures

[phcaan]

Thanks P901. Looks like I can kiss away the idea of towing my trailer and using a blade. My wife was looking forward to toting the little trailer around to carry gardening tools, pick up small limbs, and whatever else around instead of taking off the 6' finish mower from my big tractor every time she wants. We used the trailer with my old 18hp geared Craftsman without any problems for years.

I went ahead and filled the case with Castrol 5w50 synthetic and the maching seemed to drive ok for a little over an hour, until driving up a small incline to wash it off. Then the machine acted like it did not have any power. Maybe the incline is too much for this machine if it is even new, but my 18hp Craftsman made it up without any problem along with the various other inclines around the property (My LA130 is rated at 21hp). The incline is only as long as the machine but goes up maybe 30-45 degrees. Am I to assume that, if I do not use this machine for anything other than mowing, it should handle a small incline like that when it functions like new? Anyone with something I can compare normal operation with? Is this machine worth taking the axle apart to fix what may not even be broken?

I feel your pain mrfix. I was fortunate to have borrowed a neighbors John Deer when I was contemplating purchasing a newer mower. After running his for about 30 minutes it would no longer mow up hill, I had to disengage the blades, drive up the hill and mow down. When I asked him about this he told me that the mower had been doing this for a year or so and getting worse.
I started researching and found that his mower had the TuffTorq 46 model transmission. I started checking every mower I was interested in to determine which transmission they had. I ended up with a mower that has a Hydrogear G7. It is serviceable with a drain plug, level indicator plug, and spin-on filter. This forum saved me a lot of money and much disappointment.

 

[lkaskel]

MRFIX71......
I own a 2005 L130 and my property has a hill. I cannot tell you what the grade is but it is 200' long and a 35' total, even drop, over that distance. It's also 200' wide so I spend a lot of time going up hill. I also bought my L130 used in 2011. After almost an entire season the K46 quit moving. The tractor had 475 hours on it. The previous owner had a flat property. After reading this thread I felt like the biggest issue the K46 had was the original oil in the tractor was the 10W-30 instead of a higher quality 5W-50 synthetic. Tuff Torq recommends the 5W-50 but it appears that John Deere may have requested the cheaper oil causing the transmission to fail prematurely. The confusing thing to me is John Deere markets the L130 as being capable of using a blade or pulling some implements so I would think it should be able to. Anyway, I took the route of rebuilding mine and using the 5W-50 from the start. The parts were under $200 including 3 day shipping and the oil was another $30. I am on my 3rd season with the rebuilt transmission and it still works great. I am hoping that I am right about the issue and I will get a few more seasons out of this tractor. One thing I will say is when I pulled the transmission apart the internal filter was almost solid with build-up. If that was the case I can understand how the transmission was starving for fluid and causing many other problems. I did change my fluid again this weekend out of a desire to do some good and the old fluid seemed ok. It was dirty of course but it did not smell like it was burned. I would say if you had another similar in size hydro-static tractor that performed like you needed then this one will too. I previously owned a Yard Man 15HP hydro-static with a sealed transmission like this one and it lasted 13 years doing the same work. I pull a small utility trailer behind mine as well. Just do the rebuild, which is probably a 4 or 5 on the scale of 1-10 in regard to difficulty for a home owner. There is more than enough info in this thread to guide you. If you decide to do the rebuild PM me and I will send you my order sheet so you can see what I purchased as a reference. Make sure you buy a new filter as well as a new fan. The only "special" tool you would need is a snap ring plier and a torq wrench. The other tools are normal things like a socket and wrench set.

Best Wishes!!!

Best wishes!!!

 

[mrfix71]

I guess I will open the case in a month or so (I have to go out of state for 3 weeks) to see what is going on inside. Hopefully it is just a dirty filter but even minor repairs appears to be far cheaper than a new mower regardless. A local small engine salvage yard operator told me he completely dispises hydrostats and didn't have any around. His recommendation is to dump the hydrostat and put in a geared transaxle. His attitude may be based on his interest in modifying lawn mowers for high-performance racing and tractor-pulling. :confused2:

 

[chasdall]

I bought my L 130 in June 2003. It now has 514 hours and I have used for mowing and quite a bit of snow pushing. Tranny went out and I changed the fluid with only being able to get the yard cut about half ways before it stopped. I decided to buy a new tranny for $509 on the internet. I Ordered it on Monday night and had it Thursday afternoon. If I can get 11 years out of this one I think I will be OK.

 

[wactbn]

Here's an update on my K46AC that was rebuilt by sandpapering the case/pump/motor a year ago. After working well all summer, this year's harsh winter took a toll on the K46 while I was snowblowing my driveway as well as my two neighbors'.

The first sign of trouble was in February when it refused to move at during very cold mornings, protesting with a loud bypassing sound after I floored the pedal. I eventually figured out if I could rock it back and forth a bit, it will eventually catch and warm up, and then I could do my snowblowing with no further trouble. Two big snowstorms later, the heat-induced issue came back, and it could only run for about 20 minutes before it would start bogging down and have trouble going up/down hills.

I finally took the K46 apart last week, and saw the same scoring as before on the case, along with a lot of aluminum and iron flecks in the screen filter.

The Castrol Edge 5W50 was very dark and looked burnt. My differential gears were already quite worn from before, and I think that's probably the prime source of iron in the filter and oil. I think the premature failure was caused by having residual metal in the case and not flushing the oil out completely last time.

After sanding the case, pump and motor, I found someone on Ebay selling like-new differential gears and like-new T40 pump motor with case, screen filter, and IDS filter (really just a couple of magnets). This combination cost under $200 shipped, compared to almost $400 if buying new parts from Tuff Torq, so I went for it. The new differential gears took back a lot of the slack that I had with the worn gears. The only thing from the T40 that didn't fit was the wedge, so I re-used the K46 wedge.

T40 case, K46 case:


T40 wedge (notice the extra lip next to the shaft bearing), K46 wedge:


Now I'm back in operation with new Castrol Edge 5W50 oil. It will be interesting to see if this setup will last longer than the sandpaper trick.

 

[mick waters]

Hi I have a broken axle on the right hand side only is it possible to buy the axle not the whole unit it a tuuftorq k 46
Thanks mick

 

[RBLapham]

Buy parts direct from Tuff Torq. Call them is easiest way (423) 585-2000
https://www.tufftorqservices.com/instance1EnvEELogin/html/login.html

 

[TiminNC]

Hi Guys ... ran across this forum when looking up my Transaxle and trying to troubleshoot my issue. My mower has a Tuff Torq K46 ... The other day I noticed a huge puddle of oil under the transaxle ... after inspecting for the leak, there is a puddle on the top of the axle where the bypass (or Neutral) shaft enters into the top of the axle. I originally thought that the oil was coming from the seam, but it appears it is coming from the top and leaking over the edge. I also noticed that the rod that attaches to the Neutral shaft and extends out the back of the mower doesn't seem to be working. Moving the rod in and out meets with NO resistance.

I'm going to remove the axle either sometime this week or over the weekend and inspect closer but has anyone ever had an issue with oil leaking from the top of the axle and running down the side? Maybe it's leaking out the top and from the seam ...

Thanks ... Tim

 

[NYDolfan928]

RBLapham - I sent you a private msg regarding service manuals - did you get it yet? thx

 

[tonypvt]

Great thread - Been following it for about a year. I too have a failing K46AC transmission - from a John Deere L120 with ~350 hours on it. Transmission is now at the point where the machine no longer climbs the small hills of my yard. In addition to replacing the pump/motor/filter/center case, I noticed (as some others have) that the differential gears were damaged and that the magnets were covered with debris. So I will also be replacing the differential gears.

I know most folks on this forum would probably advise me to order everything through Tuff Torq, but I found a seller on ebay who had parts from a K46CA (vs K46AC) which included: pump/motor/filter/center case. Price with shipping was ~$125. I think WACTBN (see post #726 above) may have used the same supplier. Just wondering if anyone else has used this supplier and what experience they had?