TuffTorq K46 Repair Guide with Pictures

[RBLapham]

the D170 uses Kanzaki Tuff Torq HD K46 so you are in the right thread. You wish it was a K66 - the K66 starts with the X500 series I think - $5,000 up. There is an upgrade kit on the web to put in a K66 but it costs about what you paid for the D170.
Keeping the rpm's up does help keep it cooler and helps it last longer. Also keep the trans clean to cool better. A 4.5 hour run is bound to heat it up a lot. I use it about 1 hour or less at a time and more for plowing snow so mine should last a long time. I also drained the trans at 50 hours and refilled with 5W50 synthetic - also good to help it last longer.

 

[doxford jim]

Hi guys,

I have just got a reply to an enquiry I sent to TuffTorq. It appears that I have the K46BE transmission on the JD D170 rider mower. I will check when I get back home, but this is what the manufacturer says.
So RBLapham - you are right, it is the K46 tranny. I guess I will need to remove mine and do the necessary work - and that will most definitely include putting in two drains for the oil changes.
Many thanks to everyone that has contributed to this thread - it will save a lot of heartache for owners and give them a reasonable cost repair over the expensive replacement prices.
Thanks again.
Jim

 

[Molerj]

Hi guys,

I guess I will need to remove mine and do the necessary work - and that will most definitely include putting in two drains for the oil changes.
Jim

Keep in mind, if you put in the drains, you will still need to remove the transmission to fill it. I didn't see the need to put in drains on the ones I fixed.

 

[Jumbo1114]

First... your re-build blog was great... thx for posting it.
Second... ALAS the accomplishment is a temporary repair... the K46 does not permit the user to Check, Top-off or Drain/Change the fluid... and unless you take the necessary steps to correct that issue... the trans will only fail again.
I have an L120 with 146 hours on it... was at the back of the 3 acres I mow with it, when the tractor began moving rather slowly. I made it back to my garage and parked it. After numerous readings of the MANY "L" series owners having trans problems... I decided to try an easy $20 fix.
1 - Remove Trans from machine; remove cover plate and drain fluid for a full day.
2 - Add a quart of kerosene and swish it around for 5 to 10 minutes... let it drain for at least an hour.
3 - Drill and Tap the cover plate for a 1/4" petcock (I used a radiator type)
4 - Re-fill trans with 15w-50 synthetic oil.
5 - Remove vent cap on top of trans and gorilla glue a 5/8" dia thinwall rubber hose in its place... hose should be 18" long.
6 - Drill 5/8" dia. hole about 2" from edge of gas filler tube at 7 O'Clock position.
7 - Re-install trans and route the rubber hose up through the hole you just drilled in the rear cowl.
8 - After trans has been re-attached, pull gently on the rubber hose to remove any slack... radiator hose clamp it in place.
9 - using 2' of #12 solid copper wire... run it down the hose until it stops... pull it out and make note of where the oil shows up on it... that's your FULL mark. I bent and crimped the end of the wire to reflect the full mark at the crimped tip of the wire. I used an old radio knob I found that fit perfectly into the rubber hose and drilled a 1/16" vent hole in it and then drilled a 3/32" hole for the wire... I inserted the crimped end of the wire into the tube... slid the radio knob over the wire and pushed it in the rubber hose... I pulled wire up a bit to clear whatever it was hitting at the bottom and gorilla glued it to the radio knob.
I can now check my trans fluid, Top-off the fluid, drain and change the fluid.
I only have about 22 hours on this fix... but, so far, machine is working as it did when new.
My countless calls to JD, TuffTorq and other service agents were fruitless unless I wanted to spend $1,500 to upgrade to the K-66 tranny. I cannot fathom that a manufacturer would purposely install a "throw-away" trans into any piece of equipment... but JD did just that and they don't care howed ticked-off the owners get when the realization sets in that their "Quality JD" machine quits on them. Sooo... I've created this web-sit to try to get JD to do something about their failed JD "L" series tractor trans.... http://johndeerek46.yolasite.com/
Check it out and see if it is something you might want to pursue.
Jumbo

 

[JSH1]

My countless calls to JD, TuffTorq and other service agents were fruitless unless I wanted to spend $1,500 to upgrade to the K-66 tranny. I cannot fathom that a manufacturer would purposely install a "throw-away" trans into any piece of equipment... but JD did just that and they don't care howed ticked-off the owners get when the realization sets in that their "Quality JD" machine quits on them.

The K46 is not a "throw-away" transaxle. The K46 was designed to be serviceable and is sold to other manufacturers with drain screws and plastic expansion tanks that allow the oil level to be monitored and changed with the transaxle in the tractor. However, John Deere chose to purchase the K46 without these options and market the transaxle as a sealed unit that does not require any service. For the majority owners the transaxle does last the design life of the tractor (250 hrs).

 

[Jumbo1114]

Thx for the info... albeit not 100%.
In my numerous confabs with Tuff-Torq techies... none suggested that I should swap my non-serviceable K-46 out for a serviceable one... at least not one with the model designation of K-46. Their ONLY recommendation was to buy the re-build kit or upgrade to the K-66 trans.
I am in process of creating a list of all the tractor models that have the K-46 "non-serviceable" trans, and am surprised at how many there are so far.
Thx again for the info.

 

[JSH1]

There is a reason that everyone at Tuff Torq has recommended that you replace your K46 with a K66. That reason is that your cutting requirements far exceed what the John Deere L-Series and the K46 were designed for. You say you cut 3 acres, that is way more than is recommended for a L-Series. I'm sure you don't want to hear this but for that kind of acreage you should have purchased a John Deere G-Series. The K62 or K66 is the transaxle that was installed in the G-Series. That upgrade is especially important if you tow a trailer with heavy loads. A small trailer full of light items like brush or leaves isn't a problem but heavy loads like dirt, stone, firewood will kill a K46 very quickly especially if hills are involved.

Here is the customer that the product planners at John Deere designed the L-Series for: He owns a suburban home with a half acre lawn or less. That customer will cut grass 25 times a year which will take about an hour. 25 cuttings per year x 1 hour per cutting = 10 years of service for a tractor with a 250 hour design life.

You will find many "non-serviceable" versions of the K46 sold by manufacturers in the United States. If you expand your search to Europe you will find the serviceable versions of the K46 like the K46H used by Husqvarna in their R-Series Rider.

The K46H will easily go 600 hours and more without a problem due to the vehicle design (small wheels to reduce load on the hydraulics) and the fact that the manufacturer requires the oil in the transaxle to be changed at regular intervals. The most important oil change is the first one because as the gears wear together the small particles of metal build up in the oil. The gears wear together very quickly so by about the first 10 hours of use it is finished and the oil can be changed to get rid of the metal particles. After the initial oil change the interval can be extended because you only have to worry about the oil breaking down, not a build up of metal particles.

 

[cchc28]

Greetings everyone. Just bought a 2002 John Deere LT150. Its a 2002 with the K46C trans. The guy I bought it from said that he was plowing this winter, and while pushing snow, he heard a pop from the rear, and it just stopped. He says it will move a little bit, but thats all.

I am thing that I should pull the trans and do a basic rebuild, as described throughout this topis (which by the way, you have ALL done a great job). Any of you guys who have experience with this K46C have suggestions on where to start? I will be pulling the trans sometime next week, and woudl like to order parts.

As far as the tractor itself, I can tell it has seen some hard use, and I know the trans has never been rebuilt. Any help is appreciated.

Ryan

 

[cchc28]

UPDATE TO LAST POST:

So I had a few minutes to start to check out this machine. While still up on the trailer, I fired the engine off. When I disengaged the brake pedal, the drive belt began to engage and I noticed that the pully on the input shaft to the transmission was just spinning on the shaft.

Broken key?

Also, any ideas if it could REEEEEEEAAAALLLLYYYYY be this simple, or has this happened to other people? either way, I have to pull the trans to get to the pully and put a new key in.

 

[JSH1]

cchc28: You really just have to open it up and see what is broken. From your description I would expect to find a broken reduction gear.

EDIT: The input shaft doesn't have a key it has splines. While it is possible that the splines just stripped out that doesn't explain the pop.