Tech Tips – Using Tuff Torq Repair Kits

Tips for Tuff Torq Repair Kits

(K46, K57, K574, T40 MODELS)

The Tuff Torq service team has put together this summary outline procedure for using our Tuff Torq repair kits to service your drive system. These are just tips and should not be considered a complete repair guide for every issue you might have. All repairs and maintenance of our drive systems should be performed by a professional service technician. If you have any questions or need specific help for your issue, feel free to contact our service team at (866) 572-3441 or through the website by clicking here.

Receive the correct repair kit

  • First, clean the outside debris from the unit.
  • Be sure to locate the proper serial number of the TTC unit (Located on the barcode sticker).

Removing unit for repair

  • After you have received your parts, please inspect the parts. Note the mating surfaces must be smooth and clean.
  • Repair Kits generally include the center case, pump cylinder block, motor cylinder block, filter, o-rings, seals, and sealant. When repairing your unit, it may not be necessary to use all o-rings, and seals.
  • Drain the oil from the unit. (DO NOT reuse the oil) Remove the flat rubber seal cap located under the fan to drain the oil. No need to remove the vent valve.
  • Place the unit on your workbench with the fan facing down.

Opening unit an performing repair

    • Remove the case bolts and remove the lower housing.
    • Scrape the sealant from both the upper and lower cover. Be careful not to damage the sealing surface while scraping the housings. (Remove all sealant completely)
    • Now is the time to use the drawing and parts list from TTC’s website to identify everything inside the unit
    • Clean and flush the unit. Improper cleaning of the unit could result in a premature failure or void the parts warranty. You can clean internal parts with standard brake cleaner.
    • If you choose to inspect any parts make sure these parts are placed back into the proper orientation. (Ex. If you remove a bearing or a plate make sure that it is placed back into the proper position. Plate with smaller ID (INSIDE DIAMETER) should contact Pistons.) The notes are listed on most drawings so be sure to follow these tips properly. (see Fig#1)

      Using Tuff Torq repair kits - Figure 1

      Using Tuff Torq repair kits – Figure 1

  • Note the original position of the Motor Housing. (see Fig.#2)
    Using Tuff Torq repair kits - Figure 2

    Using Tuff Torq repair kits – Figure 2


  • Once you are ready to install the parts be sure to coat the mating surfaces with oil. This will help lubricate the contact surfaces.

Re-assembly of unit

  • Make sure to re-install the bypass pin and washer from the original center case and motor cylinder block. You can use a light amount of automotive grease or Vaseline to keep these two parts in position while putting the parts back in.
  • If the unit has IDS valves, be sure to note the correct position of the ball or the filter compared to the drawing (see Fig.#3).
Using Tuff Torq repair kits - Figure 3

Using Tuff Torq repair kits – Figure 3

  • New center cases will have pilot holes for the IDS system. See figure 4 to understand the difference between IDS and non-IDS units. The non-IDS unit will not have finished machining at the pilot holes. This is simply in the case mold design of the new center-case and does not impact the performance of your unit.
    Using Tuff Torq repair kits - Figure 4

    Using Tuff Torq repair kits – Figure 4


  • New style magnet holder and two magnets (see Fig.#5 on back) for proper orientation.
Using Tuff Torq repair kits - Figure 5

Using Tuff Torq repair kits – Figure 5

  • After re-installation, check to see if everything will rotate freely.
  • It is critical that the operator maintains proper oil levels at all times.
    • Maintain oil level  at 20~25 mm (3/4”~1”) below the lip of (black cap) the filling port.
    • Always check oil level when the oil temperature is at room temperature (20C or 68 F).
    • When replacing oil in your unit, Tuff Torq Corporation recommends using Tuff Torq Tuff Tech™ hydrostatic drive fluid when rebuilding Tuff Torq transaxles. (DO NOT use ATF Automatic Trans Fluid)

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  • Dan says:

    what is the clearance specification for the clearance between the pistons and the pump and alos the pistons and the motor? I need the specs. so I can know if I need to order replacement parts when I change the oil and filter.

  • Kevin Rhodes says:

    Hi, Have a problem with a transmission in a John Deere Lawn Tractor/Rideon Mower.
    No Drive – Forward or Reverse until the brake pedal is pressed approx half way down.
    The mower has completed 426hrs.
    No noises come from the transmission and seems to drive smoothly.
    There are 3 Numbers on the Bar Code are :- 768T2024011 , MIA10910 & 40J-0858287.
    Any help greatly appreciated as located in country Queensland Australia and the nearest John Deere service agent is approx 80 mile away.

    • ggraham says:

      For questions like that, you can always contact the friendly techs in the Tuff Torq Service Department by Phone: 866.572.3441 and

  • Luís Henrique Silveira Pareja says:

    Moro no Brasil tenho um microtrator husqvarna com transmissão K46, mas não consigo saber o tempo de troca do óleo da mesma e o pior, que óleo utilizar, com isso ela foi ficando fraca. Um revendedor do trator me indicou óleo sintético 5 w50, não encontrei o mesmo, me mandaram colocar o 10w40 funciona por 1 hora e quando esquenta ficar fraca, espera esfriar e usa mais uma hora. Acabei por trocar a transmissão por outra nova e não sei como farei a manutenção da mesma. Se possível me indique o tempo de troca do óleo e um tipo de óleo que encontre no Brasil. Obrigado pela atenção.

    • ggraham says:

      Você gostaria de mudar o seu óleo a cada 150 a 200 horas. A menos que você esteja cortando terreno acidentado ou tenha colinas, então você pode querer cortar até 100 horas ou menos. E recomendamos um óleo sintético completo de 5W-50.

  • Tony nixon says:

    I am having trouble finding parts breakdown for a K46 transmission. I am hoping to get help here. The numbers on the transmission are IA 6460-89850 and IA 6460-24163. Looking forward to your response

    • ggraham says:

      Hello Mr. Nixon,
      The numbers you indicated are embossed on the cases. Those numbers are part numbers for the cases. You would need to check for a bar code sticker on the case close to one of the axles. That would have the serial number on it and armed with the serial number you can find all the information for your transmission on the website: As always, you can call the helpful techs at 866.572.3441 if you have more questions.

  • Graeme Currie says:

    Can I retrofit the limited slip to an existing k46 at the same time as repairing?

  • jerry woodward says:

    T he bypass shaft on my k51a tufftorq started leaking oil. how do I replace the new shaft with new one and put new O-rings 1a and p10a in. how do you get the old shaft out

  • Charlie Schmidt says:

    46BL0031685 unit works great cold, and not so good hot. can I rebuild this unit? what is the kit# and the cost. Can you tell me of a local fluid so I don’t have to have it shipped. Thank you, Charlie power equip center.

    • ggraham says:

      Hello Mr. Schmidt,
      You can rebuild it and a repair kit for this model is part number 1A646099591. You can look it up on our website to get pricing. Oil, however, is not easy to say because we have tested our oil exclusively now for a while and feel it is the best choice for longevity in your transmission. As always, you can call the helpful techs at the Service Department to have all your questions answered. The number is 866.572.3441.

  • Alan taylor says:

    Center case Service kit on a k46 transaxle

    • ggraham says:

      Hello Mr. Taylor,
      The center case is included in the repair kit for your particular transmission. You would need to order the whole kit to get the center case kit. As always you can always email the Service Department at or call at 866.572.3441. The techs there will be happy to answer your questions.

  • Steve Stuckey says:

    Can k66l be rebuit?

    • ggraham says:

      Hello, Mr. Stuckey,
      Yes, you can rebuild your K66I. To find the part number for the rebuild kit you would need the serial number off of the transmission. You can contact the Service Department at 866.572.3441, then for them to get you the right part number or you can look it up on the website as well.

  • Chris Foy says:

    I need a repair kit for a k46 Tuff Torq transmission
    SN: 46AC0184312

  • Donnie Brewer says:


    Reassemble k 51 a. Now forward is reverse and reverse is forward. What did i do wrong?

    • ggraham says:

      Mr. Brewer,
      There is a wedge shaped housing that holds the bearings for motor cylinder block. It is installed upside down. Flip that housing and it will work in forward and reverse. If you have any questions you can always call the Service Department at 866.572.3441

  • gary hindman says:

    hi David, after servicing my k58a it now goes backward instead of forward and forward instead of backward is there a way to fix this? or should I just turn the seat around. thanks Gary.

  • Bernard Hinde says:

    Hi , I have a k46 s/no. 461-0011025 ( husqvarna 506 9863-02 ) and one of the ids valves was stuck in . I managed to extract both but there
    was no ball bearing or filter in either , can you advise what is correct and pt. no. please ?
    I pulled it apart because the mower has lost a lot of power and all looks ok apart from the gears in the diff so I have an enquiry for those
    with a company here in New Zealand .

    • Hello Mr. Hinde. Thanks for your message. While I am happy to help any way I can, you have 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. If you contact our professional service team, they will be able to look up and help you with the repair of your K46 unit. Hope that is helpful, have a great day!

  • Richie Leonard says:

    Hi, I have a John Deer 115 which has the tuff torq drive unit and has lost all drive power. I was just wondering if it is worth repairing this by replacing the pump and motor kit or should I just scrap the complete machine. I’m not sure how much the repair kit is yet but I understand it is going to be quite expensive. (if the machine were working it would be worth about UK 450 pounds, aprox 550 USD).
    Any advice would be most appreciated
    Thanks Richie…

    • Hello, Mr. Leonard. Thanks for your comment. I think the best advice would be to contact our service team and let them review your issues and recommend the best solution. You can email them at or call them toll-free at +1 (866) 572-3441. I hope that is helpful! Have a great day.

  • Martin walyor says:

    Good to know

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