Tech Tips – Residential IHT (w/ integrated reservoir tank) Oil Maintenance

Tuff Torq Oil Service Procedure for Residential IHT  units with Internal Reservoir Tank

Models covered by this procedure:

  • K46 Series
    • Manufacturing ID: K46AA, K46AC, K46AG K46AW, K46BA, K46BC, K46BE, K46BL, K46BM, K46BN, K46BP, K46BR, K46BT, K46C, K46CJ, K4CR, K46CW, K46HD, K46V, K46Z
  • K57 Series
    • Manufacturing ID: K57A & K57F
  • T40A & T40J

Normally the model K46 & T40A transaxles, that are featured in many tractor and rider models, do not require any servicing for the life of the vehicle. If checking the oil level/condition, it may be necessary to remove the transaxle from the vehicle.  This is necessary to access the fill port (black cap) located under the pulley and fan (see diagram below).

After removing the unit from the vehicle, place the transaxle on a level surface and remove the fan and pulley. Then remove the black cap shown in the diagram below.  Maintain the oil level at 20~25 mm (3/4”~1”) below the lip of (black cap) port (see diagram below).

Technical note: Check oil level when oil is at room temperature (20°C or 68° F) and the unit case is level and secure.

Always use the fill port (under the black cap) to drain the oil from your Tuff Torq unit. Do this by removing the cap and inverting transaxle.

Tuff Torq recommends using only using approved Tuff Tech drive fluid when servicing any of our transaxles.  Only use the fill port (covered by the black cap) to refill unit. You will need approximately 2.2 liters of oil to properly refill the unit if completely empty. The amount of oil needed may vary for your service, due to the amount of residual oil remaining in case after draining and the condition/age of the unit you are servicing.

While reinstalling the fan & pulley be sure to place all components on the drive shaft in the reverse order from which they were removed and verify proper torque for each bolt.

Tuff Torq Oil Service Procecdure Diagram

Tuff Torq Oil Service Procecdure Diagram

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  • JOE J RIEDEL says:
    Your comment is awaiting moderation.

    Hello, I have a John Deere D120 lawn tractor. I’ve replaced the hydrostat, now it won’t pull itself up an incline. Suggestions for what to do next? Thanks!

  • Rudy says:

    Can a k46v be installed on a JD Lt160 that had a K46C? What is the difference between the two units?

    • ggraham says:

      Hello,
      The logic is different between the two so if you install the K46V where the K46C was then when you step on the forward pedal it will go in reverse and vice versa.

  • John Blondin says:

    husqvarna k46 ia6460-84161 oil seals. dealer gave me a number of tuff torq #187t0134380 but they are somewhat larger.what is the correct number please.

  • Anthony Barton says:

    I have a Snapper 2691282-00 SPX 2548 48” fabricated 25 HP Lawn Tractor 150 series with the Tuff Torq K46BL transaxle, when I first purchased the mower everything worked fine, but now over the years the forward gear still works, but the reverse is barely working most of the time and when it does it is really slow, any idea as to what would cause this problem? Thank you!

  • Steffen Schirmer says:

    Hallo zusammen,
    Ich habe eine John DEERE LT 166 aus 2001 . In dem Traktor ist die John Deere Nummer Am 880203 verbaut.
    Können Sie mir sagen welcher Achstyp das bei Ihnen ist ???
    Aufkleber auf der Achse ist nicht mehr vorhanden .

    Danke
    Schirmer

  • Shaun McIntyre says:

    Recently I broke the long shaft in my mowers k46 transaxle. I order a new shaft and seals and fitted them as required before topping off with 5w40 oil. All went well for about 25 minutes then I lost all forward power and had very little reverse power. There were no visible leaks around the casing and the oil level in the reservoir was low despite having put in 2.2 litres, any ideas as to the loss of power before i remove the case again?

  • E. Yuhasz says:

    I have a K46BA0096113 trans in my craftsman mower. I removed the air vent cap and plug to check the oil level. How do i reinstall the plug and cap? are they supposed to be attached to each other? I ordered a new vent valve and the plug did not come with it. Can i reuse the same plug with the new vent valve? How does it get installed?

    • ggraham says:

      Hello,
      if you have a new vent cap it should have the plug in the rubber cap and you can install it by putting the center part in pushing it by hand to it starts in the case where the vent valve sits and you tap it lightly with a rubber or plastic hammer till it is seated.

  • Darren Robillard says:

    I have a k46 AW transaxle and broke the drive wheel axle, is it possible to change this shaft? If so will I need all new seals when I split the case open? I’m handy but not a pro by any means.

  • Justin says:

    7a646084100 no neutral noise at slow speeds and can’t reverse up grade seems slow little plastic washer broke by shifter bracket pivit

    • ggraham says:

      Hello,
      That item is on the Husqvarna side of things and I hear that it is rather difficult to adjust. You might seek the help of a dealer to ensure it is adjusted correctly.

  • ROBERT M TESSMER says:

    I have a Husqvarna yth24k54 with a rear axle serial number 46BT1233972. It has 405 hours on it and I finished cutting the grass and was in the process of pulling a lawn sweeper and the trans started to whine, and within 500′ or so it shuttered and stopped. The axle was covered in oil and it was dripping. Upon removing the axle, I found the cap had dry rotted and cracked, which caused the leak. When I drained the oil it was a dark brown/grey color. No burnt odor to it. I am hoping that I can refill and put a new cap on it and it will be fine. The magnet did have a thin layer on it. I am trying to figure out exactly what axle I have. The tag number is 7A646084181.

  • keith says:

    I have a k46c transaxle s/n46c-0011168 on a john deere lt 180 tractor . i need to know what position the wedged shaped block needs to be thick side up or down? is the narrow part of the block ever up ?

    • ggraham says:

      Hello,
      the thin side should be what you see looking down. The thick side goes into the upper case and thin side goes into the lower case.

  • Steve says:

    Why is my k46 grinding when I press the gas in and could the trans pulley be out it’s low on drive fluid but will that make it grind like that

    • ggraham says:

      A grinding noise means to me that there is metal on metal issues. I think input shaft and pulley or gears. You might have to pull the transmission from the tractor and inspect the fan, pulley, and input shaft. If all is well there you may need to open up the transmission to inspect the gears.

  • Kay Steder says:

    Good day,
    I have a gearbox No. 7A646084170 (K 46 BP) in a snapper. After 25 minutes of operation, this loses enormous power. (has 200 operating hours) Can you also change the oil on the gearbox and does it improve?

    • ggraham says:

      Hello,
      Yes, it could very well be that the oil viscosity is shot and changing the oil could definitely help.

  • Stanley Glenn says:

    Need to replace axle seals leaking but concern about if the bushing should be replace because of seals leaking but I don’t feel any play in the axle.

  • Jerry Wayne Blankenship says:

    How do you put grease back in after replacing axle seals

  • Patrick says:

    I have a K46 in a Troy Bilt Mfg. date Jan 2015. Serial number is not readable on label. Transmission # is K46 1A6468-29902 (the 68 could be 66 or 88). Tractor does not move unless it is running for 15 minutes with pedal depressed for the entire 15 minutes. Then is will inch forward a couple inches, after another 5 minutes inch forward again and then slowly pick up speed and operate fine until it is shut off and cools down. Transmission is remove and I see the fill cap. Cap is intact but deteriorating and afraid it my crack when removing it. Is the cap available if needed? Also what oil can I replace with after draining case? Any thoughts on why forward or reverse movement is non-existent. Until if appears oil warms up?

  • Terry Ott says:

    Is there any way the air purging procedure can be done with the transmission out of the tractor? The reason I ask this question is, I cant top off the oil once the transmission is back in the tractor. My John Deere is a 135 unit. Thank you.

    • ggraham says:

      Hello,
      If you put the oil level about 1/2 up the magnet you will not need to recheck as it will be at the correct level.

  • bobby says:

    my rider mtd 13a n601h729 work great in forward gears but dont want to work it want movie in revene

    • ggraham says:

      Hello,
      you should check the serial number of the transmission to see which transmission it is. I do not have good tractor data so I cannot be sure which unit you have. So, get the serial number of the transmission and I can help with troubleshooting.

  • And also how to check if it’s full of oil on the K46BT

    • ggraham says:

      Hello,
      A K46BT is full when the oil level under the sealing cap is 1/3 to 1/2 up the magnet that sits vertically under the cap.

  • K46 oil capacity and type of oil pls

    • ggraham says:

      Hello,
      It depends on which K46 you have. Check the bar code sticker on the transmission for the serial number and it will tell you which unit you have.

  • Mike Simmons says:

    OK, so I got to the “rubbery” black cap with the transaxle still on the mower. How do I get that cap off? Can’t find a “lip” or anything. Undersatnd there is a magnet under it as well?

    • ggraham says:

      Hello,
      a slotted screwdriver “tapped” under the lip of the sealing cap and pry it up using the case as a fulcrum.

  • PIERRE Arnold Jr. says:

    Fluid type and amount for and LX188 John Deere mower.
    Tuff Torq 19154-24122 upper case

  • Ed says:

    Hi, I have a JD L110 (but it has the 20hp vtwin when i bought it) with a K46. I only use it during the winter with a snow blower attachment. It goes forward ok, but has so much less power reversing. im thinking on changing the oil (drop-flip-refill) what would you recommend for oil if it only sees winter service -20F TO 40F mostly in the +20.
    do you think new oil might improve the reverse performance?
    If i see the upper magnet with a lot of metal, i would consider opening it up, so far no evidence of leaks on the shafts

    • ggraham says:

      Hello,
      The best thing to do is check with your John Deere Dealer to find out their oil recommendations. Usually, it is 10W-30 or for a K46 or T40, you could use the John Deere oil their J20C. both of those will work. Fillings on the magnet will indicate that the gears have smoothed off their rough edges unless the shavings are completely burying the magnet it is usually all right. Since in a Tuff Torq, the gear chamber is separate from the hydro chamber the filings will not be a problem. New Oil can help if the oil viscosity is shot and having a hard time holding pressure because of it. It is also a good idea as a starting point because it can be many other things like control lever not being able to move its whole arc that could be an issue as well that you will be able to check when you drop the transmission.

  • Allen Casto says:

    I have a K46 and the serial numbers are unreadable. How to tell what parts to order?

    • ggraham says:

      Hello,
      that is unfortunate. However, you should be able to contact the Original Equipment Manufacturer (OEM) and armed with the serial number of the tractor they should be able to tell you which transmission is installed in that particular tractor.

  • Amador Lopez says:

    Hi I got a K46BN trans and is in neutral cant foward or back ward any help????

    • ggraham says:

      Hello,
      You would want to check all the linkages on the tractor hooking to the transmission and make sure all is well with those. also, check all the pullies on the tractor to make sure those are all working. If everything externally is fine then you would want to change the oil in the transmission and the oil to use is a 5W-50 synthetic. A K46BN holds 2.4 quarts. if it does not get better after the oil change then the wear on the hydraulic parts is too bad for even the thick oil to help. You then would need a repair kit. and you can find that right on the website https://tufftorq.ordertree.com.

  • Roger Kingaby says:

    My 2006 Countax X series (20 ) 4 wheel drive hydrostatic mower is leaking oil from the Tuff torq K574 gearbox, the rubber oil seal needs replacing at the top of the gearbox casing, sealing the shaft assembly under the cooling fan. Can I replace the seal from the top without removing the gearbox ? Can you please advise. I believe the oil seal part no is 187T0134380 Many thanks.

    • ggraham says:

      Hello,
      I do not see these transmissions in the tractor. So I cannot say if you have to remove it or not. You do not need to split the case to change it you can do it right from the top.

  • Timothy Rude says:

    For my Husqvarna YTH21K46 with a K46BT transaxle, could I increase the travel speed by installing a slightly larger pulley on the engine shaft, or would that not work with this type of transaxle?

    • ggraham says:

      I am sorry but I cannot recommend changing the pulley to alter the specs that the transmission is designed to have. I am sure you can understand the liability associated with altering the intended workings of the transmission.

  • James says:

    I have a k46bn trans.how much for a rebuild kit?when it gets hot it won’t pull.does fine for a couple hours,then too hot and won’t pull.

  • Tom Cyr says:

    Your table “Fluids and Lubricants” does not specify the type of fluid used in the K46BT trans-axle, could you provide that info? Thanks

    • ggraham says:

      Hello,
      You can use 10W-30 motor oil; or a 5W-50 Synthetic. the best is our Tuff Tech brand of oil and the part number for a 3-liter bottle is 187Q0899000.

  • James Garnes says:

    I rebuilt the rear end in my lt 160 but when you push the petal to go forward it go in reverse what did I do wrong

  • William Mevissen says:

    I realized now that I used the wrong port to fill unit. Can you put in to much oil in the transmission? (K46A2)
    It moves if the wheels are off the ground. But when they touch the ground the tractor will not move.
    I didn’t see what port to use until I looked up on Tuff Torq Oil Procedure.

    • ggraham says:

      Hello,
      If it is acting in that way and you have purged the hydraulic circuit of air then it is probably too much wear on the hydraulic parts that the fresh oil cannot make up for. A repair kit is a hydraulic rebuild and you would need that to get your transmission running like new again.

  • gary kelly says:

    k57r transmission in a husqvarna yta24v48. noticed black gear oil is leaking out of my right rear axle tractor only has 60 hours on it after i replace the axle seal how do i top off the gear oil that leaked out and what weight oil do i use? and what part number is the axle seal.

  • dimitry says:

    hello where can i find parts in Belgium . where can i find more info how to calibrate the fulcrum at the 46 f gear ?

  • Barry Newman says:

    I do not find Tuff Torq transmission oil in the shuswap area. Please tell me the cross reference info so I can use automotive trans fluid.

  • Jerry Stollar Sr. says:

    Can I buy parts to repair my k46 in my jd lt 160 tractor?

  • Carl Ewing says:

    Following the recommended oil change procedure I’ve noticed that when the drive shaft at the top is being turned. clockwise on my K46AC, and the freewheel lever is disengaged I can grasp the turning portion of the axle (right side) and it simply stops in my hand. Is this normal?

    • ggraham says:

      Mr Ewing,
      It is not normal for the axle to just stop. You might have wear on the hydraulic parts which is allowing the oil to escape and lose pressure which is a loss of power, ultimately. it could be you need to replace those parts and a repair kit will be a total hydraulic rebuild. You can find the repair kit on the website: https://tufftorq.ordertree.com/. Or you can contact the helpful techs in the service department at 866.572.3441

  • Ben says:

    Could I replace a K46BC with a K56? Are they the same size, with the same mounting points?

    • ggraham says:

      Hello,
      These transmissions are built specifically for the tractors that they are in and swapping can cause all kinds of unforeseen issue. The K56 is a very different transmission than the K46 and no they will not interchange without major modifications.

      • Goose says:

        There is a upgrade kit for the K46 it is a K66 one of the best and heavy duty, way over what you will need and those attachments for your lawn tractor that will ruin your rigg faster than anything the K66 is made for those application. These kits are expensive but includes even new wheels to match the much heavier axle while you can still use your tires

  • William Black says:

    My shop was flooded in Hurricane Harvey. I am afraid water got into the transaxle. The top of the Tuff Torq was under about 8 ” water. Should I split it apart or just drain and put new oil?

  • Javier ibarra says:

    How do you remove the black cap seems to be stuck on? I am trying to refill the fluid because it has been leaking a little bit

  • mike russell says:

    what are the differences between a k46 and a k46ac

    • Hello Mr. Russell. Thanks for your message. While I am happy to help any way I can, you have several questions here that would be best answers by one of our service professionals. You can reach them at salessrvc@tufftorq.com or toll-free at (866) 572-3441. The short answer is the “AC” designation describes a particular control logic and specific design set defined by a particular OEM for their tractor application. If you contact our professional service team, they will be able to look up and help you understand the features and specifications of the K46AC model. Hope that is helpful, have a great day!

  • Erki Potisepp says:

    I have Ariens 46″ Lawn & Garden Tractor, 22hp B&S and i would like to change the hand gear to pedal gear (using Husqvarna YTH 20K46 parts)
    I have a question about K46 hydrostatic transmission. Whate are the main differences between K46ba (Ariens) and K46bt (husqvarna) hydrostatic transmissions. Does theoreticaly hand transmission connections fits with pedal transmission parts?

    • Hello Mr. Potisepp. There are several differences that can be designed into each K46 unit Tuff Torq manufacturers for an OEM. The main issue with using non-original parts in a repair is the danger of the non-original unit not having the same “control logic” as the original unit. Meaning, Tuff Torq has the ability to set up a transaxle to have forward/reverse initialized by the control arm in either the “push” or “pull” directions (depending on the need of a specific OEM). Using a transaxle from another OEM may create a situation where initializing your tractor in the forward direction would cause it to actually go backward, and vice versa. So, we do not recommend replacing units with transaxles designed for other vehicles. For more information, I recommend you contact our service team at salessrvc@tufftorq.com or give them a call toll-free at +1 (866) 572-3441. Hope this was helpful! Have a great day.

  • I have a tuff Torque K72 High speed transmission, and I would like to know if there is a service manual for this unit that I can get to better help be keep it maintained properly.? It’s in a 2017 Simplicity Prestige tractor. The owners manual that comes with tractor doesn’t cover good technical maintenance.
    Thanks for any info you can give me.

    • Hello Mr. Kraus. I’d recommend you contact our service department. They will be better equipped to find you the information you need to keep your K72 unit working at peak performance. You can reach them via email at salessrvc@tufftorq.com or toll-free at +1 (866) 572-3441. Have a great day!

  • Michael Lacy says:

    Wanting to know what the cost of a pump and motor for my K46 transmission would be. I’m doing a rebuild on it as the mower would not move in forward or reverse.
    Thx

    • Hello Michael,

      Since each model of our K46 transaxles is unique in its specifications outlined by the OEM, it’s probably best that you contact one of our service technicians with your specific model information. They will be happy to assist you with your request. Please feel free to contact them at (866) 572-3441 or via email at salessrvc@tufftorq.com. Thanks!

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