Tuff Torq K46 - rebuild or just drain/refill oil?

[jpilk99]

In my 'stuff I need to know but will never remember' file I have the note that the K66 transmission is stronger but much heavier. When my YTH23V42LS Husqvarna fails, that's what I'm going to try.

I’m 99% sure you’re correct that the K66 Is stronger but if I recall correctly, it runs backwards to our machines. So to go forward, you would (under current operation of your machine) tell it to go backwards.

 

[rogerson]

As many of us know, these Tuff Torq transmissions lose power over time. On my Husqvarna LGT 24K54, it lost virtually all power to climb the slightest of inclines after only 10-15 mins of use. I spent the $400+ and bought the rebuild kit from TT and ...rebuilt it, added new fluid and mmmmmmmmmmmmwah - she was like new again. (Never going to tow anything above 25lbs again!!!!). I now am having a somewhat similar issue with my JD LA175, though it only looses about half power after 20 minutes.

Big question is: Do I rebuild or just drain and refill with new TT fluid/oil? I removed that small cap in the rear of the tranny, higher up on the tranny, and when I stuck a 3" match stick down in there, it seemed quite low; barely hitting the 1/4" mark with about and inch and a half worth of the match stick stuck down in there. (Scientific, I know...). So I'm wondering whether to just take the tranny completely off the machine and just drain & refill --- or buy the rebuild kit and finish by refilling with new fluid/oil?

Any way to know if you just need fresh oil or a rebuild kit???

Thanks all.

Jay

 

[rogerson]

As many of us know, these Tuff Torq transmissions lose power over time. On my Husqvarna LGT 24K54, it lost virtually all power to climb the slightest of inclines after only 10-15 mins of use. I spent the $400+ and bought the rebuild kit from TT and ...rebuilt it, added new fluid and mmmmmmmmmmmmwah - she was like new again. (Never going to tow anything above 25lbs again!!!!). I now am having a somewhat similar issue with my JD LA175, though it only looses about half power after 20 minutes.

Big question is: Do I rebuild or just drain and refill with new TT fluid/oil? I removed that small cap in the rear of the tranny, higher up on the tranny, and when I stuck a 3" match stick down in there, it seemed quite low; barely hitting the 1/4" mark with about and inch and a half worth of the match stick stuck down in there. (Scientific, I know...). So I'm wondering whether to just take the tranny completely off the machine and just drain & refill --- or buy the rebuild kit and finish by refilling with new fluid/oil?

Any way to know if you just need fresh oil or a rebuild kit???

Thanks all.

Jay

Normally the oil and filter is changed as the oil collects moisture and other contaminants over time that will promote wear to pumps and motors.

In the tractor I had with a hydrostatic transmission, I found the cause of lack of ground power over time was due to wear to the internal relief valves. Their role is to allow pressure by-pass if something were to say stall the transmission, to avoid mechanical failure, but they themselves are mechanical and the internal springs become weaker over time causing them to engage or by-pass at lower pressures, creating transmission stall under lower loads.

I let my dealer do this repair.

 

[jpilk99]

Normally the oil and filter is changed as the oil collects moisture and other contaminants over time that will promote wear to pumps and motors.

In the tractor I had with a hydrostatic transmission, I found the cause of lack of ground power over time was due to wear to the internal relief valves. Their role is to allow pressure by-pass if something were to say stall the transmission, to avoid mechanical failure, but they themselves are mechanical and the internal springs become weaker over time causing them to engage or by-pass at lower pressures, creating transmission stall under lower loads.

I let my dealer do this repair.

Thank you. I think this sheds lights on the $64k question: whether to rebuild or not to rebuild (just flush oil and refill). Trying the latter but prepared for the former. Given the filings, I’m fully expecting rebuild. But as commented previously, I’ll have a newly rebuilt Tranny after that.

 

[tomplum]

Yep. That's a bad one.

 

[jpilk99]

Hah. I figured. I drained and changed oil. May load it back up and try it ….or order full repair and wait and just rebuild. Thanks Tom

 

[tomplum]

When I find them just kinda coated, I'll evacuate what I can, which is typically around 3/4 of a quart or so and refill with the heavy oil to help someone out during regular PM to buy them more time. It isn't much, but it's quick and easy on some. For many areas, it isn't cost effective for a shop to rebuild one. Yours definitely has lots of ferrous evidence. These have their haters, but are still way better than the plastic ones.

 

[crazyal]

You can always try to flush it by changing the oil a couple of times to try and get out anything that the magnet isn't catching. I use the Deere oil in my x500.

 

[stevem5215]

I had the 20minute problem with my K46 in my Black Craftsman Professional 24hp. I did the dump and fill with Full Synthetic 20w-50 from Advance Auto. I did put a new drive belt on for preventative maint at the same time. That tractor has been fine for over 5 years now and it is nearly 14 years old I believe. K46 isn't a bad transmission. It's a bad fluid they used in it that causes all the problems along with poor maint as most never change the oil in it.

On a side note. I just gave away a perfectly working 1972 Cub Cadet 129 hydro machine. It had the hand operated hydro speed control. The mower deck was even original on it and just the last couple years rusted by the exit chute area. It still cuts like it did when new. And that machine worked fine with a hydro unit that is 50 years old now. Try that with any machine made now! And the engine is ORIGINAL.

 

[nbpt100]

I have not done this but I have read a lot lately and watched some video. I like the idea of opening up the Case and inspecting what you can before making a decision on how to proceed. If it does not look too bad then maybe an oil change maybe worth a shot. If you see a lot of metal filings on the magnets and filter then I would not bother. Rebuild it or replace it.

I have read a lot of people changing the oil and it does not work. If it is loosing pressure it wont help. A heavier oil may alleviate the problem some. It seems like a long shot. I know someone earlier said it worked but they also changed the belt at the same time confusing what may have been the real problem. I saw one You tube video where the guy put some Lucas product in the case and he claims it worked. It was an automatic transmissions product. I am not a fan of these mechanics in a bottle. However you may want to try to find the video and see exactly what he used.

If you do not use it in the winter temperatures I would use a 20w-50 full Synthetic.
The rebuild will work. How much time can you devote to this?