TuffTorq K46 Repair Guide with Pictures

[Hellem]

Great thread and good advice did convince me to rebuilt mine:
A JD TRS180 10 years good service (estimate 2500hrs) but loss of traction.
Stripdown showed pistons were in good condition but the filter blocked with ferros black residue. JD workshop manuel notes that "Hydrostatic oil filter plugged" as reason of 5 different defects including lack of pulling power. The parts arrived from TuffTorq and the oilfilter was not the folded paper/carton type filter I had taken out but nylon mesh filter. Seeing that the filter had succesfully worked to keep metal shavings/debrit circulating I was not convinced also as the nylon did not have a metal base no where to put the magnet which also had collected a signficant volume of fine debrit. A call with TuffTorq gave the older (finer) type oil filter was no longer available and recommendation to leave the magnet out These were the items that got my K46 further then most......................
So my conclussions was that to get my next 4000hrs :thumbsup: I will need to change oil regulary and as filter changes require a total stripdown need install magnetic drain plugs to keep the oil clean between changes.
Drilled and taped the 2 drainholes to suit the magnetic drain plugs I got from my local motorfactor (Take care with the plug near the dif.: it will hit if the magnet is too tall). Then relocated the reservoir to the top of the rh wing. (Carrefull routing the tube from the transaxel to the wing to ensure free flow)
These modifications will allow regular oil changes and ensure (???) long life to the mecanics in that box.
Thanks to all for contributions hoping that's my last "deep tactor" surgery:thumbsup:

 

[evo803]

One thing: it's possible that the transaxles intended for 22" tires use a different gear ratio than those intended for 20" tires. Short of disassembling a variety of transaxles and counting gear teeth, I'm not aware of any way to determine this with any certainty. If this is true, then I'd have to agree that you're probably better off with the intended gear ratio. Also, the maximum rated output torque, which is widely quoted at 123 lb-ft (IIRC) would be proportionally different for 20" applications than for 22" applications.

It would be helpful, but not definitive, to see if the part numbers of the intermediate gear or the ring gear on the differential are different for transaxles intended for the two tire sizes. Maybe some of the readers here can post up their K46 variant along with the tire size so we can compare internal part numbers.

I know that Hydro Gear use different final drive ratios and that is what dictates max tire diameter to be used on certain transaxles. The 2 ratios are 26.1:1 and 30.1:1 . The 26.1 ratio is for up to 20" tires and 30.1 ratio is for up to 25".

 

[GeneralEclectic]

A JD TRS180 10 years good service (estimate 2500hrs)

That's impressive! You must treat your equipment well to get that many hours on one of these.

You might consider using those two holes in the bottom to add an external pump and filter. There are small 12V pumps that ought to work and spin-on filter bases that you can attach to the frame remotely. I'm seriously thinking of doing this even though it would void the warranty. Since there's no head pressure, the pump only has to overcome the resistance of the filter, which ought to be fairly low. This has the added advantage of making oil changes very easy since you can pre-fill the filter and use the pump to fill the rest of the system. I'd enjoy seeing how much crud a real filter would catch in a few hundred hours of operation.

Another thought: Could you count all the gear teeth when you have your transaxle open? Maybe we can accumulate some information on what's exactly in these.

 

[GeneralEclectic]

I know that Hydro Gear use different final drive ratios and that is what dictates max tire diameter to be used on certain transaxles. The 2 ratios are 26.1:1 and 30.1:1 . The 26.1 ratio is for up to 20" tires and 30.1 ratio is for up to 25".

Maximum forward ground speed could be a clue to this. Seems that all K46 applications I've seen say 5.1mph. Unfortunately, I didn't pay attention to tire size. But if a tractor with 22" tires is specified for 5.1mph and one with 20" tires also for 5.1mph, there's probably a good chance that the gear ratios are different for different tire size applications.

 

[piratesignal]

Great thread and good advice did convince me to rebuilt mine:
A JD TRS180 10 years good service (estimate 2500hrs) but loss of traction.
Stripdown showed pistons were in good condition but the filter blocked with ferros black residue. JD workshop manuel notes that "Hydrostatic oil filter plugged" as reason of 5 different defects including lack of pulling power. The parts arrived from TuffTorq and the oilfilter was not the folded paper/carton type filter I had taken out but nylon mesh filter. Seeing that the filter had succesfully worked to keep metal shavings/debrit circulating I was not convinced also as the nylon did not have a metal base no where to put the magnet which also had collected a signficant volume of fine debrit. A call with TuffTorq gave the older (finer) type oil filter was no longer available and recommendation to leave the magnet out These were the items that got my K46 further then most......................
So my conclussions was that to get my next 4000hrs :thumbsup: I will need to change oil regulary and as filter changes require a total stripdown need install magnetic drain plugs to keep the oil clean between changes.
Drilled and taped the 2 drainholes to suit the magnetic drain plugs I got from my local motorfactor (Take care with the plug near the dif.: it will hit if the magnet is too tall). Then relocated the reservoir to the top of the rh wing. (Carrefull routing the tube from the transaxel to the wing to ensure free flow)
These modifications will allow regular oil changes and ensure (???) long life to the mecanics in that box.
Thanks to all for contributions hoping that's my last "deep tactor" surgery:thumbsup:

You're kidding me... can't use magnets with new filter! Yes, I have the same new style filter, but didn't know about this until your post. Now adding magnetic drain plugs will be required.

Not sure where to get Magnetic Drain Bolts and I don't know what a Motorfactor is, but can you tell us the dimensions of the drain bolts you installed? The case is aluminum, so are the drain plugs brass? Anything would be helpful.

Thx!

 

[Hellem]

Piratesignal: I got my magnetic drain plugs from my local garage mechanic and he also drilled and tapped the two bosses that Tufftorq have cast into the cover (the bosses that have a drill pilot hole cast on the inside of the cover (one can't miss!) If you still cannot find magnetic drain plugs try http://www.magneticdrainplug.com/automotive.html and post here which one you ended up fitting. As I said as short as possible because the crown wheel is close!!

The though of putting an electric circulation pump en remote filter crossed my mind but the engineering involved and starting price of the pump $150 alone....... Also considering the hours I got from my transaxel I beleave that now with the oil tank up on the wing regular oil changes will do me for at least an other 10years.

 

[piratesignal]

Piratesignal: I got my magnetic drain plugs from my local garage mechanic and he also drilled and tapped the two bosses that Tufftorq have cast into the cover (the bosses that have a drill pilot hole cast on the inside of the cover (one can't miss!) If you still cannot find magnetic drain plugs try http://www.magneticdrainplug.com/automotive.html and post here which one you ended up fitting. As I said as short as possible because the crown wheel is close!!

The though of putting an electric circulation pump en remote filter crossed my mind but the engineering involved and starting price of the pump $150 alone....... Also considering the hours I got from my transaxel I beleave that now with the oil tank up on the wing regular oil changes will do me for at least an other 10years.

Hellum,

Thx for the info. I am going to split the case on this thing tomorrow, then I measure for drain plug length and order online. This will add a couple days to the project waiting for the plugs, but no big deal and well worth it.

Nice setup you have there.

Thx!

 

[JH3]

LotsofGreenGrass,
I want to thank you for your post. My Husky 20K46 had issues last year and bought a drive belt and it seemed to work. This year it started acting up again and another new drive belt did not help at all.
I bought the parts you recommended from a local small engine repair shop for $225 and another $30 for oil and RTV.
I have to laugh at myself a little because I dropped the pan on the transmission before finding your instructions and all the pieces you warned us about fell out.
I put it all back together with the new parts. It took over 2 qts of oil so I had to get another one to top it off..
It seems to work great with one minor problem.
When I press the forward pedal, it goes backward - really fast!
When I press the reverse pedal, it goes forward
I swear I put all the parts in correct and there is no way to do it wrong and can't for the life of me think of what happenned.
I do not think so, but could I have put part#36 Motor Housing in upside down?
Happy and frustrated at the same time.
Thanks again for your help.

 

[piratesignal]

Split the case tonight, cleaned everything and, installed new parts. After reading all these posts about that little pin that can fall out, I said to myself that will Never happen to me. Yep, I got pin treatmant! No big deal though. When you start taking parts out of this thing, have a large enough work area that things can fall out but not fall to the floor and be lost.

I cleaned the case with parts cleaner and then used shop towels and an air compressor to get all cleaner out. Hold a shop towel over the unit when appling air to keep cleaner from going everywhere. I went through a lot of shop towels through the entire rebuild to keep the work area clean and organized.

When I first split the case, I must admit I was a little freaked out! I had a beer and just kind-of looked at it for awhile. But then slowly started to wor on it. The rebuild took me about 3 hours to complete. A lot of time spent cleaning and removing the old RTV sealer.

One thing that happened, when I took the case apart, the brake activator was stuck to the case by the RTV, so I had no idea what orientation it should be in for re-installation. I checked the exploded view on TT's website twice to figure it out.

The other thing, is that my replacement parts included an upgraded magnet system. The trans now has four magnets instead of two! However, I am still not sure how this magnet braket should be mounted. I may have to call TT to be sure I have this correct, so for now I have everything covered up and have to wait until Monday to talk with TT.

Pics are:

1. Ready to open the case
2. Case opened (it was much cleaner and better shape than I expected!)
3. Cleaning the trans
4. Rebuild complete
5. New Magnet bracket and how I think it should be mounted
6. Close-up of magnet bracket with magnets installed. It is upside down in the pic.

I want to thank Lotsofgrasstomow for starting this awesome thread, and everyone else for contributing!

So I closed-up the case today. I applied RTV and it is sitting now since this morning, I'll give it until tomorrow afternoon when I fill it with oil, and begin the purge process.

There was a question regarding the upgraded magnet bracket, but after further study and re-reviewing the exploited diagram I elected to proceed.

I think the purge process is absolutley neccesary. The one pump is mounted vertically into the housing, the other is horizontly. Priming the vertical pump is no problem, the horizontal pump is another story.

There is talk of using a cordless drill, but my unit affixes the the drive belt pulley and fan with a c-clip. There is no nut to attach a cordless drive to. I will have to research this.

Anyway, I will have my tractor back in business late afternoon tomorrow.

And it is Lotsofgreengrass... and not, lotsofgrasstomow!

My apologies.

 

[piratesignal]

btw, in pic 3 I have the brake actuator in the wrong way! I still hadn't figured it out. The Done pic (pic 4) shows it correctly.

 

[evo803]

LotsofGreenGrass,
I want to thank you for your post. My Husky 20K46 had issues last year and bought a drive belt and it seemed to work. This year it started acting up again and another new drive belt did not help at all.
I bought the parts you recommended from a local small engine repair shop for $225 and another $30 for oil and RTV.
I have to laugh at myself a little because I dropped the pan on the transmission before finding your instructions and all the pieces you warned us about fell out.
I put it all back together with the new parts. It took over 2 qts of oil so I had to get another one to top it off..
It seems to work great with one minor problem.
When I press the forward pedal, it goes backward - really fast!
When I press the reverse pedal, it goes forward
I swear I put all the parts in correct and there is no way to do it wrong and can't for the life of me think of what happenned.
I do not think so, but could I have put part#36 Motor Housing in upside down?
Happy and frustrated at the same time.
Thanks again for your help.

Take a look at post #19 of this thread , it looks like you installed this part backwards and will need to tear it down again to fix it.

 

[piratesignal]

The completed the K46 rebuild last Sunday, but wanted to share some additional findings I made along the way.

I think bench testing and purging the system is really a required step. When installing the new parts, it is easy to prime the pump that sits vertically, but the other one sits horizontally, and the oil tends to just drip out. When I bench tested mine, the oil level did drop just slightly, so I topped it off. If I had not bench tested, there would have been no opportunity to top it off.

I used Castrol 5w - 50 synthetic, cause thats what the parts store had. Also, Amsoil and Royal Purple were 15w - 50. I wanted to stay with the 5w - 50 weight.

Also The pulley shaft on my K46 has no nut, just a c-clip. Trying to figure out how to attach a drill to it was a challenge. It turns out that a 1/2" drive extention had just enough grip on the shft, and worked fine.

After re-installing the k46, I started the tractor and very slowly went forwards and reverse a couple feet at time. It hestitated for just a second the the first time going forwards, but then seemed to have full traction after that. I think bench testing really paid off here.

I kept going longer distances in forward and reverse and with greater speed. After a while I just went at it on hills, climbed into and out of a steep ditch. Full traction has been restored, and then some.

Below are some pics.

LotsofGreenGrass, you are the Man!!

 

[GeneralEclectic]

Also The pulley shaft on my K46 has no nut, just a c-clip. Trying to figure out how to attach a drill to it was a challenge.

Congrats on completing your project successfully!

An FYI about the oil: the synthetic you bought is, without a doubt, far better than the API:CD 10W-30 that was in there to begin with. Unfortunately new oil carries the API:SN designation that has LESS friction reducer in it (they're afraid of the long term effects of friction reducer evaporation and deposition on cats) than API:SM. I stocked up on Mobil1 SM for the cars when it was still available. (it was a lot cheaper then too) The Amsoil racing oil I mentioned previously doesn't have an API certification at all due to the very high quantities of friction reducers. Since it's used for off-road (i.e. non-cat) applications only, they can load it up with the good stuff. Also, the difference in viscosity between 5W and 15W in the low temperature range that we'd usually use our tractors is minimal. You might need to worry a little about it if you expected to do some snow plowing at -20F, but then, the K46 would be a rotten choice for that usage anyway. You'll find similar amounts of variation in viscosity between brands and subtypes within brands at typical tractor startup temperatures.

Since I haven't taken one of these apart for myself, maybe you can comment on this notion: would it be possible to install two general purpose nuts on the input shaft and tighten them against each other? (I don't know what the shaft looks like, obviously) Then you could use an ordinary socket on the top one with a hex drive adapter for the drill.

One more question: Was there some particular reason you chose to use the vent opening to fill the unit with oil? Isn't there a magnet under the usual fill hole that ought to be removed and cleaned? Did you do that?

 

[piratesignal]

One more question: Was there some particular reason you chose to use the vent opening to fill the unit with oil? Isn't there a magnet under the usual fill hole that ought to be removed and cleaned? Did you do that?

LOL! Good observation. The vent was leaking and badly cracked, so I decided to just use that to drain and fill. When I bought the parts, TT didn't mention getting a new fill cap, and I thought I might break this thing taking it out, and with there $25 minimum parts order I thought I might end-up in a jam. I cleaned the magnet with parts cleaner and a long nossle tube, and then an air compressor. That magnet had suprisingly little metal on it, but the other one was caked!

Next time I do this, or for anyone else doing this, you should order both the vent cap and fill cap along with the rebuild parts.

 

[buffy12590]

How about putting a magnet inside the large filter on the top which is round about 1.5" diameter as it appears in pictures. Wouldn't that do a better job than the small one already installed. Any reason why this isn't feasable?

 

[auraaura]

Help! I've just finished rebuilding my K46AC. It made a "pop" a few days ago and quit. Hadn't been losing power or anything. I found lotsofgreengrass's write up and decided to give rebuilding a try. When I took my tranny apart I found that the differential gears were trashed. Teeth sheared off and the transmission full of metal particles. I cleaned everything out, replaced the differential gears, put in the cylinder block motor and pump kits (per lotsofgreengrass's instructions) and a new filter. Filled it with 5W50, fired it up, and nothing. I've done the air bleeding procedure until I'm about crazy. I've gotten the tractor to run a "little". It will sometimes run but with a very loud groaning sound. Then it will stop completely. I can do the air bleeding thing again and it might run for a little while, then stop again. When I do get it to run it goes OK in forward, but when I try reverse it will go at only 1/2 pedal depression, if I push the pedal all the way down it stops. Weird...I'm at a loss as to what the problem might be. Anybody got any suggestions? I'd tear the thing apart again but don't know what to look for.

 

[desert1957]

First of all I would like to thank everyone on the Forum for their help.
I was very lucky , My (JD L120) K46 lasted 700+ hours before giving up the ghost.

During my overhaul everything you guys mentioned happened, LOL.

1.The little "Tic-Tac" pin fell out.
2.The Horseshoe clips fell out (differential)

Nothing broke internally but it needed a lot of parts I didn't think I would need and was glad I ordered. The pictures were a great help. I printed them out and out them. Stuck in a laminated folder and were used quite often during the whole overhaul process.

Pump, Motor, Filter, Fill cap, Vent Plug, Per 1 forum member's recommendations I ordered the "Spider Gear" set for the Differential, After a thorough cleaning of all parts I found the gears so worn they actually had sharp edges and were horrendously pitted from trash in the oil.

My overhaul took what seemed like a long time to bleed after start up, I had the usual OMG feeling of what did I do wrong or leave out. But eventually everything is back to normal or should I say SUPER normal.

Still has a very very small whine, but with triple the power and torque I'LL take it!

So let me say to anyone who thinks they can't do it , You Can.

Thanks again,
Desert

 

[desert1957]

Help! I've just finished rebuilding my K46AC. It made a "pop" a few days ago and quit. Hadn't been losing power or anything. I found lotsofgreengrass's write up and decided to give rebuilding a try. When I took my tranny apart I found that the differential gears were trashed. Teeth sheared off and the transmission full of metal particles. I cleaned everything out, replaced the differential gears, put in the cylinder block motor and pump kits (per lotsofgreengrass's instructions) and a new filter. Filled it with 5W50, fired it up, and nothing. I've done the air bleeding procedure until I'm about crazy. I've gotten the tractor to run a "little". It will sometimes run but with a very loud groaning sound. Then it will stop completely. I can do the air bleeding thing again and it might run for a little while, then stop again. When I do get it to run it goes OK in forward, but when I try reverse it will go at only 1/2 pedal depression, if I push the pedal all the way down it stops. Weird...I'm at a loss as to what the problem might be. Anybody got any suggestions? I'd tear the thing apart again but don't know what to look for.

Sounds like the little pin issue that likes to fall out, Its critical for pedal operation.

 

[auraaura]

I pulled the transmission back out of the mower and tore it back apart again. The bearing that goes under the cylinder block pump had literally exploded. When I drained the oil out of the transmission ball bearings were falling into the drain bucket. What the **** happened I have no clue. Anyway I ordered the thrust bearing upgrade kit (which appears to have all the damaged parts I'll need) and I'm going to try again. Everything is all cleaned up again and I'm waiting on parts. Thanks for the help, I'll let you guys know how it goes.

 

[abeal]

It's been a while so I thought I'd bring this post back up. I have a L120 that I need to do the rebuild on. My question is, what's the deal with the center case? TT says it should be replaced. I see that they have little filters now instead of the BB's. Can you get just the little filters and springs? I haven't taken mine apart yet...just trying to put a parts list together. Any help is much appreciated. Thanks