Tuff Torq Loss of Power – Tips to diagnose and repair

Replacing Worn Cylinder Blocks and/or Center Case

Is your transmission experiencing a loss of power or no drive when it reaches operating temperature? Diagnosing issues with power loss on your hydrostatic transaxle can be a daunting ask.  As always, we recommend that you seek the expert opinion of your local service dealer in these situations.

Finding the Root Cause for Tuff Torq Loss of Power

However, if you want to take care of the issue yourself, here is some helpful information.  In a majority of cases, a loss of power in a Tuff Torq hydrostatic drive system can be tracked to one root cause. It is likely that the cylinder blocks and center case need to be replaced.  If you need to repair this issue, it is critical to replace all components. This would include 2 cylinder block assemblies with new pistons and springs, and the center case. If the cylinder blocks or the center case has damage due to wear, then related parts will also.  If all parts are not replaced, it is very likely that you will have another failure within a short time.

There are many misguided blogs on the internet that say you can save money by not replacing all components.  This may be true in the short term. However, it will result in drastically shortening the life of the parts. Therefore, causing a situation where you are doing the repair again much sooner than necessary.  At this point, you cannot simply replace the components which you avoided in the first repair, as they will be damaged and you will still have to replace them to properly repair your unit.

We offer a complete repair kit that includes the center case, cylinder block assemblies and all gaskets, filters and sealant required to complete the repair. Genuine Tuff Torq repair and replacement parts are available on our service site here. If you have questions, please contact our professional service team here or by phone (866) 572-3441.

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  • Roger Bailey says:

    I replaced the pump and motor in my K66 to fix the loss of power, After I reinstalled the transmission reverse is fine however forward is week. almost feels like the pump is cravitating or loosing oil. the longer I run it the worse it was getting.

    • ggraham says:

      It now would be a good time to check all the externals including the shock absorber on the control lever. You would need to unhook it and run the tractor for a while and see if it is stronger in forward. also, check the Keys on the axles and hubs. Two good places to start troubleshooting.

  • Brad Morgan says:

    I have a John deere LA 115 I’m trying to figure out if I have to much play in my belt and it’s slipping or if I need to rebuild it. Can you tell me how much play the belt is suppose to have please. The mower has lost power and won’t pull itself up and incline at all.

    • ggraham says:

      That would be a better question for John Deere. I do not get to see these in the tractors and a John Deere service tech should know tension on the belts.

  • Patrick mcnally says:

    Hi who is my Tuff Torq distributaries in Uk please. Thanks Patrick

  • AR Warrena says:

    My Husqvarna dealer said tractor has a K46BT it turns out it is 57R which I discovered when changing to syn oil. Problem was not solved with the new oil. There is still a long delay when trying to go forward, but no delay in reverse. If I hold the forward peddle down it will eventually start to mover and attain normal speed. 144 hours and 5 years on the tractor only used for grass cutting no winter operation. Does Tuff Torque offer a rebuild service, does it have a recommended rebuilder, does it offer refurbished units?

  • Brian says:

    I have a JD LT180 with a K46C with about 700+ hours on it. Recently it started losing power on hills, checked the drive belt and it was heavily worn and damaged. Replaced it and mower ran good for about 3 cuts (approximately 7.5 hours) and then power loss began again. It got to the point to where after about 30 minutes of cutting I had no power to go up a hill. I pulled the transmission, and changed the oil, 1 qt of 5/50 and 1 quart of 5/30 synthetic oil, at the time I thought it only took 2 quarts, so I know I’m .25 quarts low now. There was a little very fine material on the magnet under the drain plug, but no large pieces. I cleaned up the magnet and reassembled everything, but got the same result, 30 minutes of cutting and all torque was gone. I do smell some burning rubber, and the drive belt gets extremely hot, is this normal with a failing transmission? Or do I need to be looking at something else?

    What advice would you give me to go on from here?

  • James Cardinale says:

    The transaxle on my simplicity region says 46Z I assume it’s a K 46 I was going uphill heard a sprawling sounded like a spring broke now in forward and reverse it just makes a raspy squealing noise . It feels like it wants to move but it doesn’t . It’s a 2006 Simplicity regent It ran fine up until I heard that sproing noise.

    • ggraham says:

      That is a strange noise and not one I can easily assign a problem too. It is probable you will have to open up the transmission to determine the problem.

  • Nathan says:

    I have a K46 it will not move either fwd or revirse.I rebuilt with new kit still nothing or at best moves very slow in either direction.So whats next i have pulled this transaxel out so many times i should get a job with tuff torq !

    • ggraham says:

      For issues like this, it is important to check everything that could be affecting movement. The pulley on the engine could affect the belt which in turn affect the transmission operation. Also, check the pulleys on the tractor. A broken bearing could have an effect on the transmission. The pulley on the transmission should also be inspected to see if it is turning the input shaft. The linkage is also a needed check to see if it is bound up or bent or broken. It could make the control lever not move in its full arc which would then seem like the transmission could not move but it is really not building enough pressure. You should make sure the oil level is correct. It probably is but check it again. Make sure you have bled the air out of the hydraulic system by going through the bleeding process. And the last thing to check is the keys on the axles if it has them. if one is broken some strange things could happen to the transmission. If after all that if it is still not working you should contact the techs in the service department at 866.572.3441 or email at salessrvc@tufftorq.com to find out what your next options are.

  • Eugene Burma says:

    I have a John Deere Scotts product GX2554s012948 Model 2554.
    The transmission only works for a very short time. I don’t see a filter on system. Is one inside?
    What are my options? What should or could I do to further see what is possible to fix and costs.

  • preston williams says:

    I have a Scott’s 2554 with k-66 Transaxel. works fine on flat ground but not on hills. what do you suggest.

    • ggraham says:

      I would suggest changing the oil in the transmission. 5W-50 synthetic motor oil, ours being the best with a part number of 187Q0899000. The K66 holds 2.5 liters.

  • Adam says:

    I have a cub cadet xt1 enduro series
    With a k46 it will not go forward or backwards no noise or anything. It only has 34hrs on it. Any suggestions?

  • Robert Percifield says:

    Ive had it apart 2 times for axel replacements so im familar with it. I figured its time for a new transmission vs a rebuild. What are your thoughts? I dont know if i could tell by looking what the problem is.

    • ggraham says:

      That is entirely up to you. You would have to weigh the costs and aggravation needed to work on it as compared to just getting one ready to drop in.

  • Robert Percifield says:

    I have a 2554 husq with k46 aw.
    Gets slower the longer i mow and no reverse on very slight slope, engine seems too be running hot. I changed belt and found the fan on trans hard to spin. I assume its not supposed to be hard to spin by hand?

    • ggraham says:

      There should be some resistance but not a lot. It is unfortunate but you would need to open up the transmission to find out exactly what is wrong with it.

  • Peter says:

    Something happened with my K46 transmission. It’s noisy during accelerating and the acceleration is slower. I’ve changed oil but it didn’t help. What should I check or repair? Thanks

    • ggraham says:

      You would want to inspect the Center Case and both Cylinder Blocks. Paying particular attention to the metal surfaces between kidney ports on all three parts. You are looking for scoring scratches or anything that is not smooth.

      • Peter says:

        I’ve found the root cause. The oil filter inside of gear was fully dirty. After cleaning transmission working as before. The issue was that the cap from oil reservoir was lost and the oil get dirty. Is it a special cap or simply bland the reservoir?

  • Ken herrington says:

    My k 46 transmission is slipping and no power where can I get parts live in Ontario Canada

  • TROUSSELLE says:


  • TROUSSELLE says:

    Bonjour ,
    Qu’elle est la procédure pour remplacer arbre de pompe sur transmission K46C.
    Procédure for replacing pump shaft in K46C

  • DAVID HAY says:

    Bonsoir je voudrais savoir combien couterais la trousse de réparation complète pour une k46 qui va sur un tracteur tondeuse toro N74590 seie 210000395 . Merci de votre réponse

    • ggraham says:

      First off you would need to contact your distributor in France. Then, they would need the serial number of the transmission to get you the correct parts.
      Crosnier SA
      Route de Boullion
      Bonnelles 78830
      e-mail: info@crosnier.eu
      Telephone: 011-33-1-308848
      Fax: 011-33-1-30413159
      Web site: http://www.motoculture-crosnier.com
      Countries Served: France, Portugal, Spain

  • Joe Pittiglio says:

    hello, i have a scotts/jd S1642 with the k51-A transmission. it started screeching and would barely move. i pulled the transmission and opened it up. changed oil with 5/50. all gears looked great. then after i put it back together i realized it was only the pump shaft and pully that had worn splines. i ordered your shaft kit and a new pully from jd and replaced them, no problems there. now the tractor wont move. i was only able to fit about 1 and 3/4 qts of oil. i went thru the bleed process with the wheels off the ground. at first they barely moved, now they wont move at all. i am going to drop the tran again to check the oil level. , all linkage is hooked up correctly. any ideas on what i need to look for when i drop the trans again? exactly how is the bleed process supposed to be done. thank you in advance for any info you can give.

    • ggraham says:

      That transmission holds 2.25 litres. So if you do not have close to that amount of oil in it it does not have enough oil. Try pulling the filter out that sits in the bottom of the fill area. It should allow the rest of the oil to flow in.

  • Stan Edwards says:

    I have a husky 2654 it wouldn’t pull about 15 mins and quit took the cover off , after removing rear unit it was almost full of water , k46 , which was not supposed to be in a garden tractor , I need the seal kit for this unit. , I found a hole in the seal on top , all gears and pumps seem to be fine , pistons and springs seem to have plenty of pressure , I need to get this unit going been down almost a year now , every is at odds on what oil to use !

  • Thomas Duren says:

    I have a k46 that the wheels will turn with the bypass lever pushed all the way in. When it is jacked up off the ground the wheels will spin but can be stopped by hand wont move on the ground.

    • ggraham says:

      It sounds like there could be wear on the hydraulic parts. You would need a repair kit which will replace those parts. Please contact the service department at 866.572.3441 or email at salessrvc@tuftorq.com with the serial number of your transmission and they will be happy to assist you in getting the part you need to return your tractor to new.

  • Frik Du Preez says:

    Im having transmission problems with my baron ride on mower. I ve had it repaired and it ran beautifully for about 30mins until the power to the wheels slowly dried up and i was fortunate to get it back inside. On inspection the following day there was an oil puddle formed under the transmission area. Its a tuff torq k46q S/N: 46q-0002549, SMPL P/N: 1721022 according to the badge on the sticker. Im relatively capable and would like to get it back operating if I knew I could reasonably repair the issue. Can you advise.

  • raymond says:

    after rebuilding k 46 gearbox .and fitting back to the ride on it happens funny thing..when i engage drive lever to go forward it goes backwards,and opozite when to reverse it goes forward ,rideon is honda 1211.any sugestions

    • ggraham says:

      Hello Raymond,
      You have inserted the motor housing in wrong. It needs to be flipped 180 degrees. The motor housing is usually wedge-shaped but can be a box with a built-in wedge. Once you flip that housing forward will then be forward.

  • jackie cress says:

    i changed the oil , i replaced the belt , same results , i went in to it only to find parts missing , according to parts diagram the model number is 7a646084100 is this unit suppose to have a torison in side where the control arm is because there is not one there , .i don’t see where any of the parts are really worn out i just see a few parts missing according to parts diagram , i talked to a technican and he said it was k46 ba and they don’t have those springs

    • ggraham says:

      Your technician is correct, the K46BA does not have a torsion spring on the control lever internally. It has a different system that is all external. If you have any further questions about your transmission you can always talk to the helpful techs in the service department by dialing 866.572.3441.

  • jackie cress says:

    i have a craftsman dys 4500 with a tuff torq k46 transaxke it does not pull good in foward unless i pull the pedal back with my foot mit has a new drive belt on it , i changed the oil ,,, but still have the same problem it’s even slower in reverse ,, any suggestions other than a bad transaxle

    • ggraham says:

      Changing the oil in the transmission is a good first step in troubleshooting a sluggish transmission. We recommend a 5W-50 synthetic motor oil be used. You can get the best oil for your transmission right off of the Service Parts website: http://www.tufftorqservices.com. When removing the transmission from the tractor you will be in a good position to check the linkage And the fan and pulley to make sure they are functioning properly. As always you can call tech support at 866.572.3441 to get all your questions answered.

  • Kevin says:

    Hi I have a sears lawn tractor and there is a bearing type noise in reverse it not if I push a little pressure on the pedal .Also I don’t see any fluid in the reservoir and how do I service the transaxle I also see a cap on the case?

    • ggraham says:

      Hello Kevin,
      I would recommend that you change the oil in the transmission. After the purging of air in the system you should check to see if the issue is better. And remember you can always call and discuss this with a tech in the service department at 866.572.3441.

  • Shane Kennedy says:

    I am having trouble with a K46DF transmission on a Husqvarna ride-on mower. I replaced the thrust bearings on the hydraulic motor, the old one had disintegrated. Now, I can go forward (weakly) when the front box is disengaged and backwards when the back is disengaged. I am fairly sure that the hoses cannot be switched. Not surprisingly, a loud whirring noise is generated by the disengaged box through mechanically back driving the gears and motor. It is a friend’s mower, so only occasionally get over to look at it.

  • matthew hough says:

    Regarding Tuff Torq 7A646024041 S/N: 46E-0045394 (UK Countax 478000301)
    This is the 3rd time i have had to replace this failed hydroelastic drive transmission on a Westwood lawnmower (approx 2002) due to power failure forward and reverse after grass cutting for about 15minutes.
    I cannot afford to keep replacing this item.
    Can you let me know cost of complete repair kit and/or new replacement complete part for the above trasmission.
    If I replace the whole lawn tractor with newer version is the updated hydroleastic transmission likely to have similar problems after eg 2-3years.
    This has been the main failing of my lawnmower.
    Thank you.

  • Steve Smith says:

    My transmission quit working while mowing. Upon teardown everything looks good except the filter is plugged. I’m having trouble accessing your website. I found a different phone number, I’ll call that.

  • Kim Boggs says:

    I need to get this kit: We offer a complete repair kit that includes the center case, cylinder block assemblies and all gaskets, filters and sealant required to complete the repair. Can you please advise the cost. Thank you!

    • Hi Kim,

      We’ll be happy to help! The best way to insure we get the right repair kit for your unit is to call our expert service technicians and have them review your issue and recommend the parts you need. You can call our toll-free number at (866) 572-3441 or visit our service website at http://www.tufftorqservices.com . When you call, please have your serial and model numbers off your transaxle so that we can quickly look up your unit and help you with the parts you need. Have a great day!

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