Tech Tips – Residential IHT (w/ External Expansion Tank) Oil Maintenance

Oil Maintenance Procedures for Residential IHT units with External Expansion Tank

Designed to be trouble-free

Normally the Residential IHT (K46), that is featured in many tractor & rider models, does not require any servicing for the life of the vehicle. However, if there is a desire to check or replace oil, it may be necessary to remove the transaxle from the vehicle to access the black cap located under the pulley & fan. Due to the design of our units,

Maintenance Overview

First, remove the transaxle from the vehicle following OEM instructions. After placing the transaxle on a bench surface remove the fan & pulley and pry open the black cap and remove magnet (see Fig #1). Invert transaxle to allow oil to drain from case through the port under black cap.

Tuff Torq K46 Oil Maintenance - Figure 1

Tuff Torq K46 Oil Maintenance – Figure 1

Refill transmission case with oil through same port to near top of case. Tuff Torq® recommends refilling transmission with Tuff Torq® hydrostatic oil, available from our service and aftermarket department.

Reinstall magnet & cap. While reinstalling the fan & pulley on drive shaft be sure to place all components in the same order as they were removed.

In heavy usage applications oil changing is recommended after the 1st 50 hours of operation and every 200 hours, thereafter. The filter should never require changing unless the transaxle is removed from the tractor or rider and opened for repairs.

Finally, after purging the transaxle of air, add additional oil through tank opening (under vent valve) to recommended oil level. (see Figure #2 below for recommended oil level).

For more information, or to order your service parts and accessories, please visit our service website here.  For technical support, you can call our service team at (866) 572-3441.

Tuff Torq K46 Oil Maintenance - Figure 2

Tuff Torq K46 Oil Maintenance – Figure 2

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  • Nolan says:

    Hello. I have a k46bn on my husqvarna gth2654, i recently broke the left axle somehow and i am trying to figure out what axle repair kit i need for this transmission. Thank you

  • Bobby Ball says:

    Hi. I have a countax with a K46E .
    On start up the mower will not move but if you give it a push and drive it for 50 yards it is then fine..
    The mower is 15 years old and had moderate use
    Can you help?

    • ggraham says:

      It would be a good Idea to try to change the oil in the unit. That is a great first troubleshooting step to take. You can check all the externals and make sure they are working correctly. If it gets better than it was the oil if not then you know that the hydraulic parts are probably worn.

  • Shannon Heaverin says:

    Can I use 15w-50 in the transmission. I have 3 quarts of it already.

    • ggraham says:

      Though it is easy to think other oil types will work in replacement of the recommended oil, our oil is actually a very special blend designed to be used in Tuff Torq transmissions. Even the 10W-30 we have is not normal motor oil. these are specially blended to be used in these transmissions. So though you can use whatever you would like the recommended oil, as I stated before, is designed to be in the transmission.

  • Justin says:

    Sorry one more question…. The sticker on my JD D160 K46 says 7A646084121. Can you tell me the oil capacity?

  • Justin says:

    How can you “purge the air” with the transaxle on the bench? I’ve read the procedure to do it with the transaxle installed, but on a John Deere D160, I’d then have to pull it back out to top off the oil since there is no access to the top of the transaxle.

    • ggraham says:

      Purging air on the bench does not get the build-up of RPMs to make the transaxle run strongly. Typically a drill will not get you the power you need to do this quickly. It is best to install the transmission back into the tractor and purge it up on jack stands. Filling the typical K46 with oil halfway up the magnet is a good level for the oil to be at pre-air purge.

  • Benjamin R says:

    Also transmission has to come out doesn’t it?

  • Benjamin R says:

    I have an lt 166 j.d. and have noticed a little oil on the back of the gas tank. I’m guessing it’s from the transmission and seems like it’s lost a Little pulling power. Do you have an idea on fluid capacity and fluid type? Any help would be appreciated

    • ggraham says:

      Thank you for your inquiry,
      Capacity is approximately 2.4 quarts. I am including an image of where the oil level should be.

  • Glenn MacNeil says:

    We have a Cub Cadet ride on the mower will work for awhile then starts slowing down going up hill. Oil was never changed in it. Can it be low on oil or has the oil broken down so badly it has ruined the transmission? There is 220 hrs on the machine but we cut hilly terrain . Thanks Glenn.

  • Eddie Lambert says:

    Pulled transmission apart changed oil put back together/ now mower goes forward on reverse pedal and forward on reverse pedal, what hav we done wrong.

    • ggraham says:

      You have installed the wedge-shaped motor housing upside down. Flip it around 180 degrees and it will fix the issue. So if the wide side is towards you put it down so that the thin side is towards you. Or vice versa.

  • Jack Mendelsohn says:

    I have been readng all of the Q & A and will be draining the trasmission and changing the oil and am considering adding Lucas transmission additve. I would appreciate your input on this.

    • ggraham says:

      Tuff Torq has not done any testing on the additive you mentioned. Therefore, I cannot give advice on whether you could use it or the safety or efficacy of the additive. You can add it if you would like but I cannot give advice to do it.

  • AR Warren says:

    Husqvarna YTH24K48 I understand it uses a K46BT transaxle. When stepping on peddle for forward motion there is a long delay, tractor starts to move slowly until getting to normal speed. If stopped it restarts just as slowly. In reverse no dely at all. Engine runs fine, rpms remain constant. 144 hrs on tractor about 5 years old

  • Stephen says:

    Hello I have a K46A transaxle and I took it off the unit as it would run for 20 minutes and then stop moving. I let it rest for 20 minutes after the oil cooled down and then the unit would run for another 20 minutes. I just saw a video that showed how to drain the oil from it and noticed that there was hardly any oil in the unit, and whatever I was adding thru the air vent would come out after it heated up. Could it just be that I need to add oil to the unit and put it back together instead of rebuilding it? The unit does not whine or make noises when it moves but after 20 minutes it stops. Thanks for your advice!

    • ggraham says:

      the best first step is changing the oil in the transmission. Getting fresh viscosity in the unit will help determine if it was just the oil or there are some other issues. Use a 5w-50 synthetic, our tuff Tech oil is best but you can try what you can find. Most K46’s hold 2.4 quarts. As always if you have other questions you can contact the Service Department at 866.572.3441 or email at

  • Bobby shepherd says:

    1870 Christopher Trace Is the center section on a John Deere what makes in go in forward and reverse ?

    • ggraham says:

      The control lever makes the transmission go forward and back with the swash plate squeezing the pistons of the pump cylinder block. The motor housing determines if the control lever going towards the front of the transmission makes the transmission go forward or backwards.

  • Justin says:

    Will 20w50 work in a k46

    • ggraham says:

      I do not have any testing data on that weight of oil. We only test with the oil that is installed in the unit or our recommended oil. You can try using anything but officially I cannot say if it will work or not. Of course, as a recommendation, the superior oil to use would be our premium Tuff tech oil part number 187Q0899000 and it is $28.50 for a 3 liter bottle.

  • D. Konze says:

    I have a K46BE in my JD L130. I changed the filter and oil using Tuff Tech recommended oil. The trans drive belt started to slip badly. I replaced the belt and much improvement. But, it still slips going up a grade, even with a helper spring on the tensioner. Do I need to go to a lighter weight oil? I read that JD uses 30 weight.


    I HAVE A TUFF TORQ K46DM HAS RED FLUID LEAKING FROM BOTH AXELS. JUST WONDERING WHAT TYPE OF FLUID SHOULD BE IN THIS? This tractor is 2015 with 90 hours on it… not sure if I should change the seals or the fluid?

    • ggraham says:

      There should not be “red” liquid leaking from the transmission. We install 10W-30 in the K46DM. Unless someone changed the fluid it should be a motor oil in the unit.

  • Rexford Parrish says:

    What about the second black cap that is not under the cooling fan assembly. Do I drain that as well and what type and how much fluid goes back in the unit?

    • ggraham says:

      That is the vent valve and when you drain the oil it will also drain the chamber (gear chamber) under that cap. Filling at the sealing cap under fan and pulley stack up will also fill the gear chamber. So the same oil goes in both chambers.

  • Ken Smith says:

    Thank you, ggraham. I will save this information. My searches today suggest going stronger may be more important than just pursuing a locking option.
    I found a reference to updating the K46 with K57 internals. Do you have any knowledge of this?

    • ggraham says:

      It is unfortunate but we no longer offer that as a service. The Engineer who kept up with all the parts changes has retired and no one has taken up that mantle.

  • Ken Smith says:

    I forgot to add the K62 is available on this tractor as an option with the large deck. The linkage could possibly be sourced from Cub Cadet.

    • ggraham says:

      I think that would be a question for Cub Cadet. Since we do not see the transmissions in the tractors it is hard to say what would work.

  • Ken Smith says:

    Greetings. My 2018 Cub Cadet XT2 came with a K46 transmission. Due to the terrain on my property I am compelled to use tire chains even in good weather. Is there a transmission (K 62 perhaps?) with a locker option that I can swap in easily?

    • ggraham says:

      There is not an easy swap between transmissions due to the fact that these transmissions are built for the specific tractors that they are installed in. That being said there is a company in Washington, not affiliated with Tuff Torq that has a K66 upgrade. His contact information is below.
      Roger Daisley
      R J Ranch
      142 Hatley Rd
      Pullman, WA 99163
      (877) 333-8811

  • Luis says:

    Hello. My husqvarna k46 is not driving. I noticed that a rear tire has bluish oil all over it. I believe an axle seal is blown and lost oil from here. Do I need to open the transmission to replace this or does it seat itself from the outside? Also I read about using 5w50 syn. Oil. Does this seem correct.
    Thank you

    • ggraham says:

      You can change the seal from the outside without splitting the case. look at this link for more information:Axle seal replacement As to the oil we do recommend a 5W-50 synthetic oil if you are doing an oil change.

  • Montri Chaisakul says:

    I have a Craftsman Garden Tractor. It works fine for the last 10 seasons. It started to stop and transaxle winning before it climbed the hill but it cut grasses fine in flat area in 11st season. I removed the transaxle from the tractor today. This is the info from the transaxle:
    TUFF TORQ 7A632084620 S/N: 66Y – 0002589
    HOP PN: 199973
    The reservoir has only small oil left in the tank. However, I have not drain the oil from the transaxle yet. There is no leak (as far as I can see from the housing. I would like to change and refill the transaxle fluid. What type of fluid it uses and how much? The reservoir has marks and show the level of fluid. However, there is no dip stick on the transaxle housing. How do I know that it is the right amount of fluid?

    I will greatly appreciate any info that you can provide.

    Best regards,

  • Tyrone Moore says:

    this Transaxle is loosing oil by spacer split how to stop it or how can i find a Transaxle

    • ggraham says:

      Which transaxle is it that you have? If I know that I can help pinpoint parts or a replacement. There should be a barcode sticker containing the serial number of the transmission on the case close to one of the axles. Get that number and call the helpful techs at the Service Department at 866.572.3441 and they will help you.

  • John Hawes says:

    I followed your instructions for oil change and bleeding air.
    I have a Husqvarna YTH24V48LS
    Refilled with 10W50 synthetic oil but now it loses all drive after approx an hours operation.
    Any suggestions?

    • ggraham says:

      It would seem that the oil is not able to make up the difference for the wear on the hydraulic parts. You would need a repair kit which is a complete hydraulic rebuild. You can contact the helpful techs in the Service Department at or call at 866.572.3441.

  • Mike Ormord says:

    I just received my new transmission and noticed it was full of oil. Do I have to drain the oil out and put new oil in or is it good to go?

  • Jason Chlebowski says:

    My LTX1045 is leaking oil from the vent valve. I have added oil to the transmission several times and it continues to lead from the vent valve. I do have 125 hrs on it. How do I eliminate this problem?

    • ggraham says:

      If oil is coming out of the vent valve then the transmission must be experiencing some rather rough treatment to make the oil heat up and expand that much that it is leaking from the vent valve. You might want to check to see if the fan is intact. Otherwise, I would change the oil and see if that helps.

  • Garnet Luick says:

    2004 LTR180 with K46A external expansion tank. How do I check the trans oil level? Can I simply top up the oil in the expansion tank to keep the trans oil level at the correct level or or I have to add oil in the oil port under the fan?

  • rusver briceño says:

    hola tengo una husqvarna con k46 y el problema en esta es que después de 20 minutos de trabajo pierde toda la fuerza y ya cambie el aceite y el problema persiste 🙁 ¿que es lo que estara pasando?

    • ggraham says:

      Hello Mr Briceno,
      It sounds like there could be wear on the internal hydraulic parts. The oil is using this to escape pressure especially after it warms up and thins out. After checking everything externally like the pulleys and the linkage your best option would be to rebuild the hydraulic system or replace the transmission. You can order parts right off of the website: And as always you can call the helpful service techs in the Service Department at 866.572.3441.

      Parece que podría haber desgaste en las piezas hidráulicas internas. El aceite lo usa para escapar de la presión, especialmente después de que se calienta y se adelgaza. Después de revisar todo externamente, como las poleas y el enlace, su mejor opción sería reconstruir el sistema hidráulico o reemplazar la transmisión. Puede solicitar piezas directamente desde el sitio web: Y como siempre, puede llamar a los técnicos de servicio útiles en el Departamento de Servicio al 866.572.3441.

  • John A DuBan says:

    I have a 2007 Craftsman MTS 5500 tractor with a K46 transmission. The number on the axle appears to be 7A646084161 SN#468N806013. The transmission quit working while vaccuming leaves and going up a small grade. It has some power going on level ground but will not climb a hill. The case is clean as there are no signs of oil leaking. What should I be looking for?

    • ggraham says:

      Hello Mr DuBan,
      It sounds like you need an oil change in your transmission to be sure of what you are dealing with. It can make the transmission run again but it is not a guarantee to fix the issue. But it is a great first step in finding the problem. When removing the transmission from the tractor you want to pay particular attention to the linkage, fan, and all the pulleys on the tractor. By checking these external issues you are making sure that they get eliminated from the list of possible issues. If all is well with the externals, change the oil and see if it helps. If it does, Great, then you had an issue with oil viscosity. If it does not get better or only slightly then you have wear on the internal hydraulic parts that the oil cannot make up for and a repair kit is what you need to replace the worn parts to get your transmission running like new again. You can always contact the service departments friendly service techs at 866.572.3441 or email at

  • Tyesen Robbins says:

    How much fluid does the K46 tranny hold?

    • ggraham says:

      Hello Mr Robbins,
      Most K46s hold 2.4 Quarts, however, there are a few that only hold 2 Quarts. It depends on whether or not the K46 in question has an external reservoir or an internal one. The internal reservoir units hold more oil.the rule of thumb is that the sealing cap with the magnet underneath of it is the easiest thing to look at for oil level. Keep the oil level at 1/3 to 1/2 up the magnet and that will be a good level for the transmission. And as always, if you have more questions you can contact the helpful techs in the service department by phone or email at or 866.572.3441.

  • do you offer a k46 with drain plugs?for a deere L120

    • ggraham says:

      Adding drain bolts to K46s that do not have them can be a problem waiting to happen and in reality not save you much time at all. The problem is having to pull off the lower case off to drill and tap for the drain bolt holes and now you have introduced a new way for the transmission to leak oil. Time is not really saved due to the fact you would have to still have to remove the transmission from the tractor to put the oil in the unit. We try to talk owners out of doing it for those reasons. However, you can always contact the friendly techs in the Tuff Torq Service Department by Phone: 866.572.3441 and if you have any further questions or for more clarity.

  • Sophia says:

    Thanks for sharing the information. i really enjoyed your blog article. and you’r writing a good point.

  • Frank Sherman says:

    Hi Guys,
    I have an L110 John Deere and had a leaking seal on the input shaft . I removed the trans-axle and brought it to my local dealer for replacement. After installing it there is no grunt in the machine. It cannot even climb a small hill. I removed it again and found the oil level a bit low so I topped it up with about a cup of suitable oil. Could this be the problem, ie. low oil? If I need to rebuild the pump assembly/motor can you supply a rebuild kit? I am in Australia and find the John Deere people here only want to sell a complete trans-axle.

  • arnold says:

    i like your page but dont go far enough some these tractors work all year round so the oil spec declare what type of oil


    Good evening. I own a John Deere L130 lawn tractor. Manufactured date 05/12. It doesn’t move at all. Raised rear wheels off ground tires do turn slowly,but I can stop simply by touching wheel. I understand their maybe a problem with K46 trans. What is my best option for the money to repair or replace.

    • ggraham says:

      Hello Mr. McCallum,
      You should check all the external things first. Making sure the control lever is being pushed and pulled through the whole arc that it can travel. Also, you should check the input shaft and the pulley making sure that the pulley is turning the input shaft. After that, you should check all the pulleys from the engine on to make sure you do not have a problem that way. If those things are all good then you might want to open the transmission and check the machined faces of the center case. Paying particular attention to the areas between the ports. that is where the oil can escape and not hold pressure and that loss of pressure is the reason you could be experiencing low power. As always, you can call the service department to talk to the friendly techs at 866.572.3441 and see if they can help troubleshoot your issue.

  • Johnny Williams says:

    I have a craftsman riding mower model 917 288561 with 150 hrs. The k46 transaxle went out and have a new one coming soon.Do i need to purge it after installing and do oil changes every 200 hrs. or so with 5w50 synthetic.I mow normal with it at home but yard has some hills and is sloped for the most part.

    • ggraham says:

      Hello Mr. Williams,
      Our Transmissions are tested at the end of the assembly line to ensure that they are meeting certain standards. So your transmission that is coming is purged, tested, and ready to drop in your tractor.

  • Steve Kariker says:

    I just inherited an 02 John Deere LTR 180 with a tuff torq K46 transaxle. Everything is working fine but there is a little humming noise when I engage the transaxle. The article above seems to contradict itself in regards to an oil change. First paragraph says “Normally the Strider™ transaxle (K46), that is featured in many tractor & rider models, does not require any servicing for the life of the vehicle.” Then “In heavy usage applications oil changing is recommended after the 1st 50 hours of operation and every 200 hours, thereafter.” What is “heavy usage?” and should I take the transaxle out and change the fluid? Thank you so much!

  • James French says:

    I have a 11 yr. old, 400 hrs. K46 in John Deere LT160, should I remove it and change fluid and was told to use 5w50 synthetic motor oil if I do !!

    • arnold says:

      what type oil for al,winter ,summerl year

    • ggraham says:

      Hello Mr. French,
      Yes, changing the oil is a good idea. The oil in the transmission will breakdown over time and keeping fresh oil in the transmission will definitely help it run. We do recommend 5W-50 synthetic oil for your change and have an excellent blend that will help the unit run longer. You can always contact the helpful techs at the Service Department if you have any further questions.

  • Tim says:

    La 165..ive drained the oil…how much is required on the refill.

  • Tim says:

    How much oil is required for the transmission oil change

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  • Wayne Elliott says:

    Is there an upgrade kit for the k46 transaxle? I plan on buying a Cub Cadet LT with a 42″ wide mower deck. I plan on using it to mow and pull a 15gal. trailer type sprayer. Will the K46 ever need servicing if I use it as stated? If there is an upgrade kit, what does it consist of and what is the cost?

    • ggraham says:

      Hello, Mr. Elliott,
      I am sorry but we do not have upgrade kits. If you need to talk with a service rep, however, you can call at 866.572.3441

  • RL Golden says:

    I own the John Deere L-120 and the transmission has failed. Imagine that? Any design that requires you to have to remove the transmission to replace the fluid is pure BS. The John Deere Manual says, “The transmission is a sealed unit that requires no maintenance” To add insult to injury they want to charge me more for a replacement than the mower is worth, knowing it won’t last either? Last John Deere anything I will ever own.

    • ggraham says:

      Hello Mr. Golden,

      We will be happy to help with your question about our oil. Please contact our professional service team and they will assist you in finding the information you require. They can be reached at (866) 572-3441 or my email at Have a great day!

  • joseph john says:

    hai dear,which oil using K46 gear box.(grade) .equipment using in gulf contry.

  • Richard says:

    Gentelmen…good mornin…heres the prob.John Deere l 118 2006 year mod…..mower working fine…needed to replace cooling fan…so i did according to procedure…mission acomplished…hoped on mower , and now no forward or reverse…replaced drive belt and drive idler ,and tension pulley asembley….no change…Now i did jack up and purge system and got slight movement but no torque…pullin my hair out in Texas…!!!!!!

  • Larry Conley says:

    I am having problems with my John Deere L130 tractor transmission slipping. Belt and pulleys are new. My tractor is a 2004 and is in very good condition. If I remove the transmission and change the oil can I drain most of the old oil from the top plug. I have observed someone trying to suck out the oil but he only got about a pint out. I may end up rebuilding or replacing the transmission but I would like to try oil first . If I have to replace the transmission should I upgrade to a k66 or another k46. If I have to replace the transmission I will contact you for what transmission will fit my tractor.

    • Hello Mr. Conley. 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 or toll-free at (866) 572-3441. They can give you recommendations on how to properly do an effective oil change and/or what would be best to check in the unit to see if repair or replacement is recommended. I hope this is helpful. Please let us know if you need anything further. Have a great day!

      • Keith says:

        Oil for pump tank 214 t mower drives power pump type of oil

        • ggraham says:

          I would need a little more information to help you. I need the serial number of the pump to know which one it is so I can get you the information on oil.

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