TuffTorq K46 Repair Guide with Pictures

[buickanddeere]

Yes, $1600. Not bad for the entire new HD transaxle. Sure beats purchasing a new mowing tractor with the 5 bolt rear rims and a ground engagement transmission. Better than having the worn out light weight K46 that is just going to fail again with blown seals or broken gears.

 

[weranix]

I also want to express my gratitude to LotsofGreenGrass and to Puchyoureyhole for their excellent illustrations which helped me tremendously with rebuilding my transmission.
My tractor is John Deere L110 with K46V tranny and 385 hrs. I used it for nine seasons strictly to cut about 3/4 acres of a somewhat hilly lawn.
When at the end of last season I've noticed a puddle of fluid under the rear end of my tractor, I immediately contacted my local John Deere dealer (from whom I bought the tractor) for advice, but the people working there were not much of help. They basically told me that it's a sealed unit not requiring any maintenance and they could not try to guess where the fluid was coming from. Since I could not tell either, as both the transmission and both axles looked completely 'normal', and since there were no other indication of any problem and the tractor continued to perform flawlessly, I decided to keep using it until ... 'something happens'.
Indeed, it did! Two weeks ago, out of the blue, the reverse first came to a crawl and then within an hour almost stopped working completely. The forward gear continued to function normally.
Only then I started researching the problem and came across this thread.
To make a long story short, I ordered the rebuild kit (almost $400!!) and using the excellent instructions from this thread and YouTube, and with an additional help from Derrick, I am happy to report that my tractor is now 'humming' like new.
Once I opened transmission, I was a little perplexed, as I could visually not detect any obvious damage - everything looked smooth and clean and only with minimal filings attached to the two magnets. My oil was also relatively clean. However, Derrick insisted that the tranny should be rebuilt, so I followed his advice.
The rebuild kit included a set of various seals and o-rings, which I ended up not using. The only other observation is that the replacement Center Case comes now with a new set of IDS valves and springs (#28A, 29A, 30A), which I ended up using instead of the old ones (with the ball), as the old valves are not compatible with the new case.
I decided not to bother with adding the drain plug, since the tranny would have to be taken down anyway just to refill it with new oil.
The entire rebuild process took several hours, as I was extra careful not to miss anything. If I had to do it again, I could probably do it in 3-4 hrs (not counting the 'drying time').
John Deere should be ashamed for not using synthetic oil, as this also could be used as a selling point.

 

[wactbn]

For anyone who's interested, my hand-sanded transaxle worked flawlessly all summer cutting grass. It seems like it has slowed down only barely by late summer so it will be interesting to see what the pump faces look like when I open it up again in the future.

After this weekend's Nor'Easter that blessed us with 12" of snow, I ran the L130 for 2.5 hours continuously snowblowing my driveway and my two neighbors'. I had no issues at all with chains on the drive wheels, and this combination handled our dirt driveways and the dirt road very well.

 

[JDL120]

I recently purchased the parts to rebuild my K46 Transmission. After completion of the rebuild, I cannot turn both axles the same direction at the same time while the tranny is in the "free state" position. That is, I have moved the lever to where the axle should be able to spin both directions (as if to be pushing or pulling the tractor). I have compared my assembly with photos and diagrams of how it should go back together,and appears to be correct.With the case open,I can move the center assembly gears by hand one direction, and it does indeed move both axles as well as the top input shaft, but it will not rotate the other direction. It seems to "lock" against the differential. Can you offer any suggestions for what I may have done wrong please?

 

[ole 815]

You might check that you have that little pin in place located behind the motor in the center case.. That little one that falls out as you lift the center case out and remove the motor barrel and plunger assembly off. When you move the lever, the shaft the lever is attached to rotates, pushes on that pin, which in turn pushes on the motor barrel and releases the oil so it can bleed out as you push mower back and forth.

I just found this site and just tore my transmission apart today. There is a video on youtube that a guy takes one of these apart and shows the pin falling out when he is taking it apart. It is only about 3/8 of an inch long or so and maybe 1/16th of inch in diameter. Hope this helps, Just a suggestion but maybe it could be something else wrong

'doublewide6' is the name of person with a 3part video on tranny

 

[JDL120]

I found the pin when I did the rebuild. It appeared to be in correctly when I tore it back apart. I believe my issue was a lack of physics. I was trying to turn the axles without the wheels on them. After I re-rebuilt it, I put the tires back on to test the function. It is now my belief that the added leverage I was able to apply using the outside diameter of the wheel allowed me to now rotate both wheels the same direction, both forward and back. I have test driven the mower and it works great. The only other thing I found to help, was to add the synthetic fluid directly into the bottom of the new pump prior to putting the covers back together. That is, while everything is sitting there ready to be sealed up, I added fluid into the pump by slowly pouring it into the center new filter.

 

[subby]

Re: TuffTorq K46 / John Deere L110 Transmission Repair Guide with Pictures

Hi,
Are these K46 trannies to be avoided? Pro's say they are reliable in Sears mowers. Planning on buying one, but no choice or option on the "K46"????.
Subby

 

[dleebold]

Re: TuffTorq K46 / John Deere L110 Transmission Repair Guide with Pictures

Hi,
Are these K46 trannies to be avoided? Pro's say they are reliable in Sears mowers. Planning on buying one, but no choice or option on the "K46"????.
Subby

Major Differences: John Deere LA and D series vs.K46(d 160-d 170) x300 series. The X300 Series transmission provides 165 lb-ft of torque and the D100 series models product 126 lb-ft of torque which is about 25% increase
Frame: 70lbs vs. 96lbs
Turn Radius:18" vs. 16"
Front Wheels: Bushings vs. Ball Bearings
Engine: B&S vs. Kawa
Hydro: K40 vs. K46(d 160-d 170) x300
Tank: 2.1gal vs.3.5
Spindles to Mower: Self tapping screw vs. heavy duty bolt & nut
PTO: Cable vs. electric
Plus other minor upgrades such as steering wheel, seat, cutting adjusments.

 

[Dapped]

Re: TuffTorq K46 / John Deere L110 Transmission Repair Guide with Pictures

Gear Wear Update.

After replacing my differential gears last spring and accumulating over 100 hours to this day, I have done a tear down and inspection.

Here's my report.

The oil was as good as the day I put it in. I did disassemble the center housing and lapped it with 320 wet on the 2 surfaces of the center case housing and the pump and motor housings.

My new gears installed last spring were the newer steel gears and not the powdered gears. There was no deterioration or wear what so ever.

I have full power and speed and can spin the tires easily when loading down the tractor

My conclusion:
The original powdered gears had too much tolerance in them with respect to axle shafts in and out play. A total of 80 thou when it should be about 20 thou total. I believe this caused the rapid breakdown of this style of gear. Once this break down starts it contaminates the oil with super fine particles, these particle are smaller in micron value verses what the filter could filter, thus causing the scoring of the pump and motor surfaces.
See: http://www.tractorbynet.com/forums/parts-repairs/164892-tufftorq-k46-repair-guide-pictures-53.html Username P901

Pictures of powdered gears here: http://www.tractorbynet.com/forums/parts-repairs/164892-tufftorq-k46-repair-guide-pictures-59.html

Steel Gears here: http://www.tractorbynet.com/forums/parts-repairs/164892-tufftorq-k46-repair-guide-pictures-53.html

As I did not shim my spider gears as Username P901 did and I do not have any gear wear I can conclude it may not be necessary if using the new steel gears. The choice is yours.

As mentioned in a previous post a build up of grass on top of the trans-axle can also stop the cooling of the fan and thus heating the oil to a breakdown temperature.

My recommendations:

1.) Make sure you have the new steel spider gears and if you don't, then get them.

2.)Keep top of trans-axle clean so the cooling fan can do what it was designed to do.

3.) Make sure you change the main oil filter...a clogged filter will cause an oil starvation to the pump....

4.) Give surfaces a lap with minimal 320 wet, it takes no time at all. I used a piece of a broken mirror and wrapped my paper on it for my totally flat surface.

Regards
Don

 

[Kyle_in_Tex]

Re: TuffTorq K46 / John Deere L110 Transmission Repair Guide with Pictures

Gear Wear Update.

After replacing my differential gears last spring and accumulating over 100 hours to this day, I have done a tear down and inspection.

Here's my report.

The oil was as good as the day I put it in. I did disassemble the center housing and lapped it with 320 wet on the 2 surfaces of the center case housing and the pump and motor housings.

My new gears installed last spring were the newer steel gears and not the powdered gears. There was no deterioration or wear what so ever.

I have full power and speed and can spin the tires easily when loading down the tractor

My conclusion:
The original powdered gears had too much tolerance in them with respect to axle shafts in and out play. A total of 80 thou when it should be about 20 thou total. I believe this caused the rapid breakdown of this style of gear. Once this break down starts it contaminates the oil with super fine particles, these particle are smaller in micron value verses what the filter could filter, thus causing the scoring of the pump and motor surfaces.
See: http://www.tractorbynet.com/forums/parts-repairs/164892-tufftorq-k46-repair-guide-pictures-53.html Username P901

Pictures of powdered gears here: http://www.tractorbynet.com/forums/parts-repairs/164892-tufftorq-k46-repair-guide-pictures-59.html

Steel Gears here: http://www.tractorbynet.com/forums/parts-repairs/164892-tufftorq-k46-repair-guide-pictures-53.html

As I did not shim my spider gears as Username P901 did and I do not have any gear wear I can conclude it may not be necessary if using the new steel gears. The choice is yours.

As mentioned in a previous post a build up of grass on top of the trans-axle can also stop the cooling of the fan and thus heating the oil to a breakdown temperature.

My recommendations:

1.) Make sure you have the new steel spider gears and if you don't, then get them.

2.)Keep top of trans-axle clean so the cooling fan can do what it was designed to do.

3.) Make sure you change the main oil filter...a clogged filter will cause an oil starvation to the pump....

4.) Give surfaces a lap with minimal 320 wet, it takes no time at all. I used a piece of a broken mirror and wrapped my paper on it for my totally flat surface.

Regards
Don

I was hoping your sanded center faces would hold up. I think your metal fines theory holds water.

I've wondered if it would help to polish the faces even finer or if the 320 grit leaves microscopic grooves for more oil to fill in.