Not sure if the original poster is still around on this thread but would love input on my mower. Craftsman YT3000 with the K46 that was a Craigslist freebie due to a few issues. One being the trans cooling fan had shredded and been missing for a couple years. I replaced the fan and the ground drive belt but now the mower goes forward very slowly and oddly fast in reverse.

I’m thinking that without the fan the fluid has gotten very hot over the years and maybe there is some internal damage.

If a fluid change doesn’t do the trick, what are the usual suspects of parts that might need to be replaced internally?

Thank you for the write up, by the way! Very helpful.

Yes I'm still around:) Funny I was going to change my K46 oil again today!! Sounds like the oil cooked like you think. Try the oil change it may work for just $25 with your own labor. Did you take it out to fix the fan? or is the Craftsman easier to get to? Tuff Torque sells a rebuild kit for about $200 to $300. A new K46 is about $700 if you search around. Some have replaced with a stronger K66 I know can fit in a Deere, but do not know on a Craftsman, TUFF-TORQ K66Y Hydrostatic Transaxle | Hydrostatic Transaxles | Transaxles | Power Transmission | www.surpluscenter.com and this on replacing in a Deere X300 John Deere X300 K66 Upgrade project

Other than spending way too long having to get the snap ring and the fan off originally, it was fairly easy to remove. Years of heat and crud made it very difficult to remove. I only had to tilt the seat up and remove the battery box to remove the fan.
I’m going to give the fluid change a try this weekend and will post results here because this whole discussion is likely helpful to a lot of people with similar issues.

Hope the oil change helps. My deere 155 still pulls well. I only had had a problem 1 time. It would not back up an incline with a 800 (at least) pound trailer hooked up to it. But then I saw 1 tire was flat! I pumped up 14 in tire and it backed up the incline. I used 15 50 synthetic valvoline from Walmart. 1 gallon was 23 and change, so I have enough for my next oil change. When I back up a steep grassy hill it spins instead of stopping and groaning. I am well pleased with the mowing and pulling performance of the 25 hp briggs. This site has been very helpful to me.

Today I changed the oil in my K46 again at 342 Hours (150 hours since last oil change). No problems. Didn't purge and all is working fine. Old oil was a lot darker than previous times - could be from the warmer weather here in south TN. No lack of speed either before or after. Also my X300 was 10 years old in January 2020 and just changed the mower belt for the first time, still on original drive belt.

Cheers to a fellow Tennessean. I’m in middle TN. As an update - the oil I drained from the transmission was about 1/3 the recommended capacity so it’s no wonder it wasn’t happy.

I was able to get the trans on the workbench, open it up, inspect all the gears and motor. All looked good with no noticeable wear. Added new gasket sealant - make sure to pay attention to where all the sealant goes, not just around the perimeter but basically divides the trans into two compartments - then locked the bolts down. Filled up with 5w50 (if I recall correctly) which was pretty hard to find, then purged using my power drill and an adapter to get all bubbles out.

Was incredibly smooth and responsive afterwards. However I did find that the torque plate was broken, the piece of angle iron that connects the trans to a frame crossmember.

Very satisfying project, especially not having to pay for a new transmission!!

20w-50 Premium Synthetic Oil is the normal practice , however 5w-50 when available would be preferred up North here when these small hydrostatic lawn tractors are utilized for plow and blower usage !

Tuff Torq specifies 5W50 Synthetic motor oil for all weather conditions. At some auto supply stores you have to ask for it as they do not put on the shelves.

Canola is NOT recommended. Unless you get the organic stuff....

Cool to see this thread live and breathe.

Hell , had 5 gallons of. used peanut oil I was going to recycle Tom ! lol.

Thank you OP for such a thorough writeup and community for helpful comments, just changed the oil in my JD X300 w/ 300hrs.

Thanks very much - very helpful. I'm trying to purge my K46 by turning the shaft. I've made sure the freewheel lever is forward as it should be for driving and have tried the forward/reverse lever in both positions but the axles aren't turning. Do you know what I'm doing wrong please?

Using a drill? The axles will turn very slow when using a drill. Also I don't remember which direction the drill must turn but try in both CW and CCW. It will probably work without purging with a drill. With the K46 back in the tractor go forward and reverse using sharp pressing on the pedals, Only thing is you can't check oil level or add oil, but it should be fine.

Thanks. I was doing it by hand. When I tried the drill it worked.

Hi there from the UK

Great write up - as everyone has already commented. Just wish I'd found it before I stripped out the K46 from my Westwood T1800....

Anyway, I hope you can shed some light on my current issues.

So, originally a shaft broke on the K46 (which I'd already welded up twice as a temporary fix and the gearbox was running fine after both repairs), so I purchased a new shaft and axle seal. These were fitted and new tuff torq oil used. Unit was purged but was making horrendous vibrations and was really slow. So, took it out again, checked all the cylinders - no scoring or signs of wear), so put back in and tried again. Unit worked for 20 minutes, but got slower and slower, then the vibrations and screeching started again and the mower wouldn't climb the tiniest incline and eventually stopped dead. I've had the unit out and checked/double checked everything several times (for peace of mind) but I can't get it to run like it was before I replaced the shaft.

If you can shed any light on what could be wrong, I'd be very grateful.

By the way, after only one session, the oil is dark when I drain it (heat??).

Maybe I need to try a different oil? I have already used the tuff torq stuff then, when that ran out, I used Comma synthetic 5w50.

Thanks in advance.

Gavin.

Do you know how many hours are on the K46? Sounds like it needs a rebuild or new unit. The oil being dark in only one year indicates over heating / over worked. The 5W50 synthetic is proper, what was the TT stuff - 5W50 also? The screeching is not good at all- replacement axle not fitting right?

Hi

Thanks for coming back to me.

The screeching and reduced speed occurs after about 20 minutes when the mower warms up, so I'm assuming the oil heats up and the viscosity is reduced, so thinner oil could be exploiting poor seals maybe (no evidence of leaks however)?

Oil goes darker after one cut, not one year, but this could be residual oil mixed with new - although I drained it pretty well!

The fan is working (before the axle replacement, the blades of the fan were broken off, but don't know for how long, so I replaced it), but I can feel the heat emanating from the gearbox when the mower is running.

I've heard people say Mobil 1 15w50 is a good alternative - is it worth trying this do you think?

I'm loathed to put in a new gearbox as it was running well prior to the axle change. Just can't imagine what I could have done to make it run so poorly.

No idea of the hours, but the machine is around 15 years old and used to cut a domestic lawn.

Thanks.

what did your chip magnet look like? Was it clean?

A bit fuzzy, but not caked in filings.

Any chance you have a bad drive pulley or crazed drive belt. Wouldn’t explain the dark oil, but vibration and screaching, maybe.

Hi - as I had the g/box off, I changed both belts to take that out of the equation. The noise is, I believe, hydraulic related and not the result of a physical imbalance/fault. I'm leaning towards oil/seals but I've changed both so I'm lost! :(

I have a John Deere x350 and was wondering if it also has the k46 in it

Yes it does - http://www.tractordata.com/lawn-tractors/002/6/2/2625-john-deere-x350-transmission.html

I have a JD D125 about 4 years old. How I know whether it has one of these K46s on it?

Edit: Aha I see from tractordata.com that it has a Tuff Torq T40. Do they have similar issues?

T40 is almost the same as a K46, yes same issues. Built almost the same too.

Thanks! I'll keep an eye on it. Only has 50 hours on it and runs fine so far. Fingers crossed.

The tic tac pin in the center case - when the tractor is "free wheeling" is that pin supposed to be sticking out of the center case or inside of the center case?

I started this thread for help in changing oil in the K46. I strongly suggest the following posts for help with repairs to the K46.

https://www.tractorbynet.com/forums/parts-repairs/164892-tufftorq-k46-repair-guide-pictures.html

Hi guys,

1. In the Netherlands iI am the owner of a Westwood mower T1600 with K46 and have similar problems as the one from Gavin Cox. Seems te me as a heating problem, why I do not have a clue. If the problem pops up I have to wait an hour to cool down the K46. It seems to me overheated oil or air ? Placed the transmission Repair Kit ( € 600) some years ago but did not have excellent results. Recently started the rebuild again (https://www.youtube.com/watch?v=NS61QpRZdl4). This is a very valueable video. I was not faced with a part problem, cleaned and filled the transmisson with 5W50. Hopefully problem will be solved now next Spring. If somebody knows the cause of the failure, please let me know.

Main reasons for overheating are - trans dirty fins, clean it, Fan on top of trans broken or stripped out. Run wide open throttle all the time to keep trans cooler. Worn internal parts may cause heat, but not very likely. 5-50 is correct oil, but make sure it is Synthetic.

Hello everybody.

Looks like I have K46 problems as well on LGT2654 .

I need to replace oil and hope it helps.

Manufacturer use 10W-30, owners use different oils.

Which do you recommended 5W-50 or 15W-50 both Mobil 1.

How about transmission fluid has anyone used that or gear oil which is 75W-90.

Thank you for advise.

Use 5W50 full Synthetic motor oil, The parts inside a K46 work with hydraulics mainly so never use a heavy weight oil like 75W90.

Thank you.

Please also check the pulley on top of the transmission. The heating problem was caused by the

pulley, which was completely worn out and had a bad gripp on the belt. Rechanged the pulley

and problem seems to be over ( final check in summer with long mowing times)

Great , thank you for a tip.

I just use a drill pump and/or a small electric pump to transfer trans fluid in/out, takes me about 20 minutes tops. I simply remove the breather vent/tube on top and feed my small diameter tube on my pump down inside the hole and pump the fluid in/out. Even easier to do this on mowers with battery under seat, remove battery and bat tray and its right there on top. Some I'll need to remove one rear wheel to access the vent hose but most mowers I just reach in from the side above the rear wheel to do it. Never had to go through this once yet.

Tube I use on my pump is rather stiff & made of Nylon/PEX material with an inner diameter about a 3/8" and my pump draws about 90% of the old oil out so it works out really great. See link below:

My first pump was an engine oil extractor kit made by Briggs Corp to draw engine oil out of engines with hard to access oil drain plugs such as self propelled models that generally have to be flipped over as their pulley/belt underneath blocks the oil plug. I ran across this Briggs oil drain kit by accident at a Napa auto parts store about 20yrs ago and paid about $12 for it I think and omg its saved me an astronomical amount of work hours like shown here over the yrs.

I'm retired now but I repaired fork trucks, hydraulic floor jacks, large injection mold machines, vehicles of all types and lawn equipment for several decades. As my health/age hinders my abilities so often now days the pump was an actual blessing in my book, believe me it really is folks.

Its "Input" hose is almost 3ft long with an "Output" hose a bit shorter. IDK why but the output side was made from soft clear/red rubber hose with an inner diameter of a 1/2"? This kits basically just a drill pump with small long hoses you attach a drill to and give it a spin. Since drill pumps only pump in one direction I must reverse the hoses on the pump to change directions to refill the trans in this manor because my larger red hose won't fit inside the hole and this slows me down some or its an easy 10 minute job with it. Because if both my hoses were small and fit in the vent hole Id just swap both ends around so my input hose is now the output and spin away to refill, if you understand this good for you, I don't know if I even did but it works like a charm when they both can fit the holes...lol.

Once your fluid is refilled you simply screw your vent back in, reinstall hose/clamp and your done folks. By far one of the best purchases I made as an adult..lol Other oil extractors manual/electric are also sold online just get a small enough line to fit down inside the vent hole your half way done with this job already!!

Couple yrs ago our farm store had a small electric pump with (2) small 1/4" PEX hoses on it on clearance and bought one. Even clearance ($5??) I got burnt since its such a pos compared to my first Briggs kit...lol Its just so under powered it won't last much longer but' I just used it again this week so its still going but yea' the p.o.c...lol See link to avoid it..

It has small +/- alligator clips to clip on the battery and just turn it on. I liked its design but the drill pump design is much better because once this motor/pump dies its trash while a basic drill pump is easy to locate when they wear out, just change it and move on. My first Briggs drill pump wore out after a few yrs so I ordered two new replacement drill pumps online for $10 each and so far I just used one. Finding the fittings to adapt a small PEX hose onto a basic drill pump can't be real hard to locate at home stores if one chooses to make one of these suckers up, it just beats removing your entire transaxle all to heck, just trust me its almost worth its weight in gold.

I also use it on newer vehicles that no longer have tranny dipsticks to refill trans fluid and on their diffs too. I just crawled under our Tundra and 4Runner and pumped trans fluid back in with this setup after draining them, the uses of a small drill pump are endless. See link to see similar but replacement pumps I ordered Red Milescraft 1314 model and worked great for yrs.

Peace

Similar to my good Briggs Drill Pump here.

https://www.amazon.com/ECO-FLO-Products-PUP62-Water-Transfer/dp/B00LIRSW0Y/ref=asc_df_B00LIRSW0Y/?tag=hyprod-20&linkCode=df0&hvadid=167157107032&hvpos=&hvnetw=g&hvrand=5929717844798184738&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9016669&hvtargid=pla-306234764344&psc=1

---------------

Similar to my P.O.S. Oil Changer below..lol

https://www.amazon.com/SeaSense-12-Volt-Oil-Changer/dp/B0019LZTQ4

Hello .

Couple of questions.

First notice breather rubber is missing. Should I install a new breather or leave it.

Second should I unscrew couple of bolts check second magnet and replace transaxle oil filter ,thank you.

Replace the breather, it's cheep. Replacing the filter and cleaning the magnets would possibly help a little, just up to you on how much work to put into it. I have never taken mine apart, now at about 350 hours and think I'll wait till it has a problem before I do. Kind of like a car - change the oil and filter, but do not take engine apart every time oil is changed. Also you didn't say how man hours or age of tractor.

Bought in 2013 it has 330 hours

About the same hours as my 2010! You are past due for an oil change if never done yet.

So, yesterday I pour half quarter of 5W-50 oil, shake it,placed upside-down, wait over night and drained .

Today opened transaxle, found 3 more magnets inside.

Clean it,replace filter looks like a strainer, clean old silicone gasket and put together.

Let's dry and settle over night and tomorrow I will put it back together, pulley looks good no need to replace it.

Thank you everybody for a help.

In my case oil change didn't help. It struggles drive incline.

Just recived new trany, should I put 5W-50 or keep it with pre-filled oil which came in?

I'd use the oil that came with it, some have 5W50 synthetic from the factory, not deere. Then run it for 50 to 100 hours or 1 year to break it in and then change to the 5W50 synthetic, If you do not want to change in in a year, yes change it now.

Good idea, I will do it like that.

Oil is 10W-30 typical Torq Tuff stuff.

Are you sure the 5w50 synthetic is correct for all k46 models? I called Tuff Torque and they took numbers off my trans and told me its the K46BR model and I should use JD high viscosity or their tuff tech oil. I specifically asked if I could use 5w50 and he said not for that model. They just being like JD trying to make sales? I have the x300 2009 year. Only 184 hours on it

i did all of the above, however I could not get more than 2 ltrs of oil in the unit. I assume it is because I did not diismantle and change the filter?

What a great help everyone is here. I thought to add my 2 cents as I have an X330. Drives me crazy why there are so many different models. Seems like I have to be very specific when ordering parts as they are not always the same as the X300. So I'm cutting the grass yesterday and towards the finish, Betsy wasn't moving forward or backwards very well. Just seemed that something bad happened. I stuck my head down behind the transmission area and it sounded to me like a grinding noise and as if something needed oil or lubrication. To make a long story short, I went through the procedures above and everything was smooth until I tried to remove the pulley and fan. My model has a bolt and not a snap ring. The bolt would just turn and move the shaft along with it. I tried a lot of things like trying to hold the shaft with some channel locks. Anyway, I did some searching on line and it turns out holding the pulley with my hand while using an impact wrench quickly did the trick. My pulley has no more teeth. Since I have to wait a few days to replace it, which John Deer's website's part number doesn't match. I cleaned the transmission up and was going to change the oil, but the oil looked very good. I have 330 hours on her and not doing any major work except cutting the yard and driving the lil wagon around with stuff in it. I closed it back up. So X330 users, be ware....

You should ALWAYS put in new 5-50 synthetic oil whenever you get the chance - its cheap insurance. Yes a stripped pulley is another common failure.

491 hours now. Pulled the K46 and changed the oil. Still using 5-50 synthetic. I'm 82 so lucky my son was here to help. Took about 2 hours as I clean everything good:) Used a new plug where the oil is drained and refilled but old one still looked fine, kept it as backup. Still will squeal the tires just like new at 15 years old. Never any repairs to the K46!! OR the X300 for that matter!