The Dreaded Tuff-Torq K46 Hydrostatic ******

[B.S.A. (ret.)]

OK guys, I just finished reading a "Lazarus" post (one resurrected from the dead) from 2013 regarding lawn tractor replacement due to bad transmission. A short search will yield numerous complaints about this "defective" item that's probably used in 60% of riding mowers across all brands. Seems funny as I'm about to embark on servicing one of those "unserviceable" Tuff-Torq K46 transmissions on my 2012 Husqvarna YTH22V42. After doing some research and looking at some youtube videos on the subject, this project seems to have a higher P.I.T.A. factor than difficulty factor. I purchased a seal kit (about $45) from Tuff-Torq as well as a drain plug kit. My plan is to drop said transmission, open and drain same, inspect for any obvious wear, spotface, drill & tap the lower cover for the two drain plugs and refill with the correct fluid (Mobil-1 5w-50 synthetic). According to the manufacturer of this ******, the factory fluid should be changed after 50 hours, and then every 150 hours or so. They also told me that the tractor manufacturers install straight conventional 10w-30 oil (for cost savings) into the dry transmissions, and specified the drain plugs be omitted (for additional cost savings), as they're in the business of selling tractors/mowers and this ensures a steady supply of customers looking to replace their bad mower.
Anyway, I'll be starting this project next week and will report my results here then.

 

[TommyK]

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[jobo1004]

I'm hoping you're embarking on this adventure before your hydrostat is having problems. If it's having problems I'd say don't do the rebuild. I did one at 200 hours and now at 250 hours I'm having trouble going up any sort of incline again (definitely not worth the expense). If you're doing this as a preventative measure, I wish you the best of luck. They're fairly easy to remove and take apart. Not overly finicky to put back together. If you've watched a YouTube video, you should be good to go.

 

[Motown]

I tried rebuilding one, with no success. But I skimped on some of the parts. And I've changed fluid in several others. What I did was spin the fan shaft as I filled it, to prime the pump. But you may have to jack up the tractor after installation and run it forward and backward, this bleeds the system. I even had one that after doing the bleed procedure, I had to let it sit overnight and it worked fine, the next day. I used Castrol 5w-50 synthetic.

 

[B.S.A. (ret.)]

I'm hoping you're embarking on this adventure before your hydrostat is having problems. If it's having problems I'd say don't do the rebuild. I did one at 200 hours and now at 250 hours I'm having trouble going up any sort of incline again (definitely not worth the expense). If you're doing this as a preventative measure, I wish you the best of luck. They're fairly easy to remove and take apart. Not overly finicky to put back together. If you've watched a YouTube video, you should be good to go.

Mine has about 325 hours and seems OK except for a bit of "growling". I'm definitely doing as a preventative measure, as I plan on keeping this thing around for a few more years. My gas tank is up forward, so if I need to change the oil in the future, all I'll need to do is pull out the battery box for full access to the fill plug, then unscrew the drain plugs I'm installing and that will be it. Easy peesy - any way, that's the plan...

 

[jobo1004]

Mine has about 325 hours and seems OK except for a bit of "growling". I'm definitely doing as a preventative measure, as I plan on keeping this thing around for a few more years. My gas tank is up forward, so if I need to change the oil in the future, all I'll need to do is pull out the battery box for full access to the fill plug, then unscrew the drain plugs I'm installing and that will be it. Easy peesy - any way, that's the plan...

If your unit is growling you may get it open and find wear on some of the gears. If the gears need replacement, I'd definitely consider doing that. I wouldn't waste your money replacing the pump though.

 

[GTA Matt]

I know it's slightly different, but I just tore down my hydro gear unit in my mower 2 weeks ago. It was whining and growling, no movement when hot. Found nothing wrong inside at all, I'm guessing the fluid had just deteriorated. They're stupid simple inside, cleaned it up, reassembled, fresh synthetic and it's like new again.

Sent from my SM-G930V using Tapatalk

 

[JohnDeere1]

I have a 2003 John Deere L120 with same trans and it has 63 hrs on it and I paid $300 for it and the guy was complaining about it over heating and having to let it sit for 30 min. I have a 1 acre yard and it has never happened to me and it pulls up hill fine. I decided a couple weeks ago to check the oil and it was low so I filled it up with a funnel with a piece of hose attached and it worked great but.....Lol for some reason maybe seals I had a puddle of oil under it the next day so now this is my issue and I'd say the problem.

It only holds maybe 50% of how much it's supposed to and I used 10w30 I think don't remember could have used 5w20 as I have both on hand. I have read about all the issues guys have had with thier mower and I guess my issues could be worst knock on wood. I had just mentioned the issue with these trans in another post as its probably better to buy a mower with a different trans like the k66.

Best of luck to you !

 

[PassnThru]

I have a JD L110 that I bought new in 2003. It has 575 hours on it and I haven't touched the trans. No unusual noises, although it does seem to run a touch slower than it used to. I probably should change the fluid but I hate to work on something that already works well. I can, and have, screwed things like that up before

 

[B.S.A. (ret.)]

If your unit is growling you may get it open and find wear on some of the gears. If the gears need replacement, I'd definitely consider doing that. I wouldn't waste your money replacing the pump though.

Understood completely. I was going to order the pump and motor beforehand, but in the course of my research, read that some guys just polished up the pistons in the motor and pump and were "back to the races". Another guy found his differential gears ground up in pieces, but pump and motor were fine. Tuff-Torq has a re-stocking charge of about 25% and shipping ain't cheap (but I am!), so open it up and inspect will be first on the list. If nothing major is wrong, in goes the new filter, drain plugs and Mobil-1 5w-50 and it's mowing time.

 

[gungatim]

that ****** is the exact reason I ditched my L130 before it died and went to an X540 with the serviceable K72....contemplated doing the drain plug thing but looked over the procedure and yeah, it's a huge PITA.

good luck, hope it works out. post up how it goes....

 

[B.S.A. (ret.)]

Day 1 Remove and inspect:
Well, good things and bad things happened. The bad things were that the wheels were rusted on to the axles. Two hours of penetrating oil, brass drift and engineers hammering finally broke them loose. In all fairness, if I still had my shop, I could have made up a simple wheel puller that would have done the job, but I had to channel my "Inner McGiver" to get things done and brute force won out in the long run.

Good news: My ****** looks to be in superb shape mechanically speaking. No piles of gear chips / debris, only a very light blackish coating of iron/steel residue on all 5 magnets, so I'm a happy camper indeed.

Day 1 status: Transmission removed from tractor, opened for inspection, filter changed out, no major issues observed. Lower cover removed, drilled & tapped for drain plugs, drain plugs installed, mating surfaces of lower cover and transmission case cleaned, re-sealed and re-assembled. Waiting for sealant to cure overnight before adding new Mobil-1 5w-50 Full Synthetic Oil, and testing of rebuild results.

Biggest PIA was trying to remove the rear wheel hubs from the axles. No oil or "Never-Seize" was ever added between the mating parts and SEPARATING THEM WAS BY FAR THE WORST PART OF THE JOB!

Stay tuned for Day 2 updates. Should have everything back together and running... Hopefully!

 

[B.S.A. (ret.)]

Update & Results:
Refilled ****** with Mobil-1 5w-50 synthetic oil, remounted it on the machine and made all control connections. Started engine and performed purging procedure per manufacturers instructions - no movement of axles in either forward or reverse - PANIC! Checked under machine for proper operation of drive belt - belt not moving. Released parking brake thereby allowing motion drive idler pulleys to engage belt (Duh!). Belt now operating normally. Commence purging procedure for the second time - SUCCESS!
Polished up axles and slathered them with Never-Seize so the next time should be a breeze. Wheels on, mower taken off of the jack stands and test-driven. Operation of transmission as designed with no growling or whining, and my subjective opinion is that the mower runs faster in both forward and reverse. In addition, the drive is more "responsive" to a light touch on the pedals as well.
One note to anyone owning a similar model mower: When the brake is released, it engages the tension on the drive idler pulleys. There is no tension adjustment on the motion drive pulleys so if you notice slippage from a fairly new drive belt, check the free-wheeling movement of the idler pulleys and replace any that the bearings have either seized or turn roughly. If that seems OK, check the return arm on the brake pedal where it contacts the frame plate. If there is an accumulation of grass crumbs and dust on the plate under that arm, full engagement is hindered causing slippage when going up even a minor slope. Mine had about 1/4" to 3/8" of an unbelievably hard "adobe cement" material that it took a screwdriver to break up and scrape off. Just something else to check before blaming the belt.

 

[GTA Matt]

I also noticed a big difference in speed with mine after switching oils. However once it got hot, speed seemed about the same as before. They're simple creatures, but it's a pretty good feeling when they're back together and everything works better then before.

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[B.S.A. (ret.)]

Thanks GTA Matt: I had no qualms going in to this project after viewing several youtube videos on the subject, but I was really nervous when I couldn't find the seat cushion after the transaxle didn't turn in my first attempt to purge the unit. That was a pretty high "pucker factor"!

 

[ddominik]

BSA can you point me to the youtube videos (K46) for drain hole location? Thanks ddominik

 

[blkriv95]

I haven't checked Youtube yet but is there a link to where to drill/tap the holes for the drain plugs?

I'm going to tackle the rebuild like B.S.A's approach.....take it apart and order individual parts and not just the complete replacement kit. Any advice on mating the surfaces? How do I know if I need to refinish this surface?

Thanks

andy

 

[jonshonda]

I've got an older Simplicity Regent (no hour meter) with the K46 that I got free from a friend. It has served me well and I have abused it on a few occasions (pulling a 5x8 trailer full of heavy leaves/wood, plus having to cart my 265lb *** with a big bagger full of leaves around the yard).

The ****** does groan/wine a fair amount and I know that the K46 isn't very stout and not easily serviceable. But if there is a decent method to extract and refill the fluid then I might have to try that. Otherwise the transmission going out would be a great excuse for me to find a nice used Prestige or Legacy.

 

[Farmer Giles]

Hello folks , nice to be here !!!
I am from the UK so be gentle !!

An interesting read this ,as most threads on this transmission arent the most helpful!!
My old Countax mower was struggling to get up banks last year and seems no better now. It drives fine on the level and does not make any noise !

I think the belt looks good and the tension seems ok ,but I cannot be sure it doesnt slip under load !!
Seemed ok for oil but I am seriously considering changing th oil or getting the trans out and turning it over to service it .
Your man Taryl from your side of the pond has been making me laugh , in fact I watched his excellent one and a half hr vid on you tube yesterday ,and it was most entertaining and informative !!
So I am going to check the belt again , (Its never had a new one in ten yrs ) the clutch travel and the oil ,before I get motivated with tear down .

Thanks again for this thread

 

[Antique Engine]

According to the manufacturer of this ******, the factory fluid should be changed after 50 hours, and then every 150 hours or so. They also told me that the tractor manufacturers install straight conventional 10w-30 oil (for cost savings) into the dry transmissions, and specified the drain plugs be omitted (for additional cost savings)

Interesting thread that I had missed the first time around.

Regarding the quoted text, that's some shady ****. Omitting the drain plug then using the wrong fluid to begin with. Shame on that tractor company. And shame on the transaxle manufacturer for allowing these things to happen to their product. If I built those transaxles I wouldn't omit the drain plug even if the tractor company told me to. Ultimately it's the trans' companies reputation that suffers when they fail.

 

[jonshonda]

I think car manufactures get away with the same ****. Ask any transmission manufacturer if they feel the transmission would operate best with never changing the fluid, and I am sure they would agree that fluid should be changed at regular intervals.

I think the EPA rules made it very difficult for vehicles that needed regular fluid changes due to fines for those fluids that need to be disposed of.

 

[Skin]

Ultimately it's the trans' companies reputation that suffers when they fail.

Maybe for the user or mechanic who cares enough to look up what transmission is in the unit but most people associate everything on the tractor/mower with the brand on the hood. Even the engine.

 

[sparky 1971]

I replaced my K46 about four years ago at about 350 hours. When I put the tractor (John Deere L130) away for the winter last fall, I thought it was shot again. It would barely move with me on it. I decided I would change the fluid when I got it out in the spring. Last month I fired it up and it ran perfectly to the garage. Hmmm. I was exhausted when I put away and think that maybe I forgot to crank the throttle up. Anyway, I went ahead and changed the fluid anyway. I read on a tractor forum to use 20W50 synthetic. I couldn't find any locally, so I used Mobil1 15W50 and have to say it's never run better and has well over 500 hours on it.

 

[sparky 1971]

I've got an older Simplicity Regent (no hour meter) with the K46 that I got free from a friend. It has served me well and I have abused it on a few occasions (pulling a 5x8 trailer full of heavy leaves/wood, plus having to cart my 265lb *** with a big bagger full of leaves around the yard).

The ****** does groan/wine a fair amount and I know that the K46 isn't very stout and not easily serviceable. But if there is a decent method to extract and refill the fluid then I might have to try that. Otherwise the transmission going out would be a great excuse for me to find a nice used Prestige or Legacy.

They are pretty easy to get the ****** out. I left the tires on mine to make it even easier. There is a fill plug on the top. Carefully pry it off and turn the ****** upside down. Refill it with good oil and put it back together. It took me less than an hour and a half.

 

[B.S.A. (ret.)]

Performed my first oil change since the modification to add the drain plugs. Simple and easy. My Husqvarna model has the battery under the seat, so I just had to pull the battery and battery box to get access to the top of the transmission. I followed the cardinal rule of fluid replacement which is, "Make sure you can refill before draining anything", and removed the fan and drive belt to expose the filler and breather caps. Once they were off, I removed the 2 drain plugs and let gravity take over. I still had a couple of quarts of Mobil-1 5w-50 (plus a partial) that I picked up at my local NAPA before performing the modification, so I was all set there. The ****** takes just a whisker over 2 quarts and once filled, I put it all back together and performed the purge routine. Tractor runs like a top and is going on 9 years old!

 

[B.S.A. (ret.)]

Greetings Sir Giles! Sounds like you have a good plan there. I would also check your idler pulleys as well as the travel of the clutch pedal being hampered by accumulated debris. A worse-case scenario would involve pulling the ****** and inverting it to drain and replace the oil, but before you go through all of that mess, try a bit of belt-dressing spray on your 10 year old drive belt. That would be a "quick & dirty" method of identifying if that is indeed your problem. Cheers!

 

[Farmer Giles]

Greetings Sir Giles! Sounds like you have a good plan there. I would also check your idler pulleys as well as the travel of the clutch pedal being hampered by accumulated debris. A worse-case scenario would involve pulling the ****** and inverting it to drain and replace the oil, but before you go through all of that mess, try a bit of belt-dressing spray on your 10 year old drive belt. That would be a "quick & dirty" method of identifying if that is indeed your problem. Cheers!

Wow , you read my mind !! I was just wondering if I should go find my old can of belt dressing . Otherwise ,if I get my son to lie alongside the mower as I try and go up the slop (at a safe distance ) then we can discount that !
If all else fails I think its out with the axle and change the oil at least (never been done

thanks now ( have you watched the Taryl videos ? )
Cant post a link because I dont have enough privaleges yet

 

[B.S.A. (ret.)]

Suffice it to say that Taryl (Dactyl) is a piece of work! However, as with all online videos, there might be a different model or variation that can twist the results. I believe that most of us here on GJ are cognizant of that fact and incorporate it into our plan. I watched one of his videos on taking apart a Sears Kenmore dryer for servicing and the disassembly was nothing even close to mine. I must say that his approach to repairs is fairly competent if not a little corny! Best of luck with your project - keep us informed on your findings and results!

 

[B.S.A. (ret.)]

A wealth of information is available from the manufacturer, here is the contact info if you need to clarify anything or find a source for parts: [email protected]

 

[Farmer Giles]

Had another look today . I think that the drive belt is ,if nothing else , well used !
I have found the deflection of it when in drive is quite a lot , but surely the belts dont stretch to any amount do they , more that they wear thinner section ?

Might treat her to a new belt anyway as the nmachine is twenty years old and I dare say still on its original !
The foot pedal hasnt got any 'junk' stuck anywhere on the travel but the spring that holds the clutch pedal in drive (when you remove your foot off it ) maybe needs beefing up a tad , as it doesnt go back all the way ! But only slight
As well as me oiling the relevant idler pivots etc ,although I have never let it get wet ever as she lives in a brick outhouse .
I believe there may be a drain plug on it too !! Yea

 

[M635_Guy]

This thread makes me want to get into the drive of my old Craftman (later sold as a Husqvarna) mower. It's got a lot of features I like - 1-lever adjustment of all wheels, rear-wheel drive, blade-brake clutch, variable speed with a squeeze-lever, Honda motor, etc. But the self-drive seems to be dead. Will spin one wheel when there's no load, but not enough grump to move the mower. Wonder if it can be recovered...

 

[B.S.A. (ret.)]

This thread makes me want to get into the drive of my old Craftman (later sold as a Husqvarna) mower. It's got a lot of features I like - 1-lever adjustment of all wheels, rear-wheel drive, blade-brake clutch, variable speed with a squeeze-lever, Honda motor, etc. But the self-drive seems to be dead. Will spin one wheel when there's no load, but not enough grump to move the mower. Wonder if it can be recovered...

I would recommend that you do, I never regretted opening mine up and having a look. There are some excellent youtube videos on the subject and as long as you're careful, the units are really pretty simple inside. The guys at Tuff-Torq are very helpful and as long as you open it up and put some eyes on the innards of your ****** before ordering parts, you should be OK.

 

[B.S.A. (ret.)]

Had another look today . I think that the drive belt is ,if nothing else , well used !
I have found the deflection of it when in drive is quite a lot , but surely the belts dont stretch to any amount do they , more that they wear thinner section ?

Might treat her to a new belt anyway as the nmachine is twenty years old and I dare say still on its original !
The foot pedal hasnt got any 'junk' stuck anywhere on the travel but the spring that holds the clutch pedal in drive (when you remove your foot off it ) maybe needs beefing up a tad , as it doesnt go back all the way ! But only slight
As well as me oiling the relevant idler pivots etc ,although I have never let it get wet ever as she lives in a brick outhouse .
I believe there may be a drain plug on it too !! Yea

Sounds like you hit a stoke of good luck Sir Giles! I would agree with you that while the drive belt hasn't broken, after 20 years it might have become slightly stretched or is even beginning to show early signs of wear. To be safe, I think it wise to replace it in the spirit of "preventative maintenance" if nothing else! LOL! You might also want to check with the boys at Tuff-Torq with you transmission model number to see what they have to say about it.
Best of wishes for your project!

 

[SeisMec]

I'm not familiar with these, but if the drive belt is a v-belt, don't neglect to check the pulleys for wear or splaying.

 

[mikelk]

My first time here and what I have learned is going to save me a lot of money. Read lots of complaints about the K46 and was nearly convinced to upgrade to a K66. After reading this thread I know that it is best just to take care of what I have.

Thanks a lot everyone for the great information here.

 

[Bigblockyeti]

The K46 in my JD L130 seems really noisy when I start to move but only for the first 10' or so then it's almost as if it's purged whatever entrapped air it might have had out and it behaves well enough. It'll still go slower up hills and fly down hill and roll down hill even when the pedal is at neutral but I don't know how much would be considered acceptable. The tractor is either an 03' or 04' with 204 hours on it and I'm sure it hasn't been opened up. It was grandma's tractor and she used it a little then had her golf course employees use it (abuse it as they did everything) almost exclusively over the last 6 years. I have a new filler cap and 3 quarts of full synthetic 15W-50 ready for this fall when I'll have time to tinker with it. In the mean time, I'm usually busy enough I forget to clean out from under the deck.

 

[B.S.A. (ret.)]

Yikes! Has that baby gone condo?!

 

[Bigblockyeti]

That was taken yesterday and it was last run on Sunday 5/24. It got funky pretty quick just sitting in the garage. Nothing got wet outside of the moisture in the grass I was cutting.

 

[McGee]

Hi! I'm happy to join this forum, which is covering a topic I have spent much time and some money on. I have looked at several other forums, including the official Tuff Torq site about the K46 transmission, which my JD X300 tractor has.
That's because, like many others, I have had frustrating issues with it, and never found a cure.
This tractor has 408 hours on it now, and I use it to to mow the lawn and snowblow my driveway too.
A couple of years ago, it would no longer go up the steep part of my yard. So I looked online, and got lots of information, but not the cause that I discovered.
I did remove, drain and refill the trans, as advised (with Castrol Edge synthetic 5W/50), and that worked for a while.
Bottom line is, all other information did not include this:
Oil leaks from the vent when going up steep hills. After a while, it will whine a lot, then eventually, will not go uphill.
I did not realize at first that it was unnecessary to pull the trans or remove the top of the tractor to fill the transmission through the fill hole. Simply removing the vent plug was sufficient; saved a ton of trouble and time.
All the problems I had that were what others had, whining, weak, not going, were caused by loss of oil. All of them were solved by adding oil.
I read every comment on Tuff Torq's forum, and never saw a mention of this, or on any other forum. So many people spent much effort, dismantling the units, rebuilding them, enduring great frustration. I was frustrated too!
Seems like it leaks oil faster now than it did when new. Maybe the vent is supposed to maintain some minimum pressure, and gets tired over time. I may try replacing it, but I already have a fix brewing in my head: an extension which raises the vent plug, so it still vents, but at a higher level, so the oil won't leak when going uphill.
I don't see why that shouldn't work.
I can't be the only person who has thought of that, can I?
I will update this forum with the details when I figure out a good way to do that.
Tuff Torq must have made tons of money selling replacement units, when there was nothing seriously wrong with them!

 

[bpjr]

What happens if you over fill? Does it malfunction, foam up, leak...?