TuffTorq K46 Repair Guide with Pictures

   / TuffTorq K46 Repair Guide with Pictures #521  
Some good data, however on the Deere X300 they have the rear tire size wrong, wonder what else is wrong? No trans repair info, just which trans is in it by model.
 
   / TuffTorq K46 Repair Guide with Pictures #522  
Very nice thread, unfortunately I found it a little late. I was given a 2003 LT 180 with a bad transmission. I purchased the below link from ebay.

John Deere New Replacement Hydrostatic Transmission LT150 LT160 LT170 LT180 | eBay

I believe it is a 46C. I installed and have been able to mow my yard with it. But I have been getting some slippng, surging to full speed then slowing down, on hills I hear a squeeling from the front pulley and even saw a little puff of smoke once. I installed a new drive belt with the new transmission but it still seems like the belt is slipping on the front pulley. Is there an adjustment to this belt or should I try belt dressing? Or maybe something wrong with the pulley? Any ideas would be helpfull.

thanks
 
   / TuffTorq K46 Repair Guide with Pictures #523  
Good day all,

I recently purchased the X300 about two months ago and at this point it has 10.0hrs on the clock. A groaning noise from the transaxle about a week ago prompted me to do an online search for information regarding the transmission.
The results of the search produced a result that I could have never anticipated regarding all of the information available for the K46 transmission.
Taking the suggestions from this thread I removed the unit and poured out the oil. It was black and full of a silvery stream of metal particles as it drained.
Ended up opening the case and installing the drain plugs. Also noticed that the final drive gear train appeared to have been "indifferently" assembled.
Not to be disparaging but the common term, "slapped together" came to mind.
(A bit about my experience, mechanic for 40 yrs specializing in Porsche transmissions).
The motor drive pinion gear slid on the motor shaft to the point where the pinion gear travelled off the end of the shaft by a third of the width of the pinion gear. (There is a friction block that "adjusts" this travel but it would appear that the assembly technician might have made a better selection as opposed to the one that was installed).
A shim for the friction block set the max outboard travel of this gear to coincide with the length of the shaft thereby limiting the uncontrolled slide of the pinion gear on the motor shaft so that the gear remains fully engaged on the spline of the motor shaft.
Observation of the initial position of this pinion gear relative to the "intermediate" gear was such that during max axial travel of these gears sliding to and fro in this uncontrolled fashion on their respective shafts produced a contact between the motor pinion gear and the intermediate gear such that only half the width of the gear teeth were engaged. I believe that this cannot be by design or then why would the engineer designer not have installed a gear half the width?
A stainless steel intermediate gearshaft shim was fabricated on the milling machine with a final fitting dimension achieved by a few minutes on the surface grinder. The intermediate gear then itself required a shim since the gear had ~1/4" travel back and forth on the shaft.
Careless production line quality or is this the standard of the fitting of precision gears in the lawnmower industry ?
The quality of the gears and shafts themselves appeared to be of a good order.

The large differential gear at its outboard circumference had a "wobble" that allowed the outer circumference of the gear to travel in a arc that was
on the order of 3/8". A strategically placed shim on the final driveshaft had the combined effect of bringing the "spider" gears into full contact and alignment along with the support of the differential gear itself on the driveshaft effectively removing the "wobble" of the gear and the excessive end play travel.
All shaft/shim clearances were adjusted to .020".


In the end the question might be, would the metal that is ultimately found over time in the oil that fouls the hydrostatic pumps be produced by excessive mechanical wear aggravated by the poor fitting of the final drive gear assembly?
(Taking into account the break in period where good mechanical practice would suggest that the oil be changed out within a short period of time from new to remove the initial accumulation of metal. )
With the excessive shaft end clearances which allow the gears to travel out of full contact and alignment with one another along with the degree of axial movement of what should be precision fitted parts the wear of these parts must be accelerated thereby loading the oil with particulate matter.
1st photo, Black oil full of metal
2nd photo, Metal fuzz on one of the magnets, 10.0hrs of run time since new, all of the other magnets held equal metal or more
3rd photo, Stainless steel shims, properly selected factory shims during assembly would not have required this additional work although
it would require the factory to train the assembly people to a higher degree and it would also require additional instrumentation,
tooling and time on the assembly line.
4th photo, Pinion gear to intermediate gear, full contact now
5th photo, Intermediate gear inside shim, the intermediate gear was allowed, by factory assembly, to travel along the intermediate shaft ~1/4"
for no apparent reason. One could see that under changing conditions of loading that this gear could conceivably, "slap" back and forth between
the factory shim and the shaft collar, (the shaft collar then with this amount of available travel would be slapped into the side of the differential
gear by the travel of the intermediate gear).

The oil will be 15-50 AMSOIL

Without disrespect, due to the fact that we are fortunate to have access to an automotive repair shop with an attached machine shop section we have no direct need for the factory warranty.
Also there will most certainly be many that will claim that this is, "the way the factory wants this".
In the many years of my occupation in this type of work I have not observed a factory that produced a quality product with this approach to an assembly technique.
It will take some convincing that this [poor] level of assembly is by intentional design as opposed to the pressures of expeditious production methods to reduce per unit cost.
It may be not too difficult to understand how such a fundamentally sophisticated unit should only be expected to last 250hrs when it is assembled in this fashion.
View attachment 318770View attachment 318771View attachment 318772View attachment 318773View attachment 318774
No work was performed on the hydrostatic portion of the unit. Fresh oil and a good cleaning will hopefully remove the pump noise.

Thanks to all that have added to the body of knowledge regarding these units.
andrew
 
   / TuffTorq K46 Repair Guide with Pictures #524  
great report 901,
I haven't torn mine apart. It has about 140 hours but has had a slight growl since about 80 hours. I am a machinist and have a nice shop at my disposal. When things at work slow back down, I'll tear mine apart and I plan on resurfacing the worn faces and such.

I'd like to think you bought a unit that was assembled on the day after the super bowl....

PS. your pictures didn't load right. All you have to do is attach them. Thanks, Kyle
 
   / TuffTorq K46 Repair Guide with Pictures #525  
Good day all,

I recently purchased the X300 about two months ago and at this point it has 10.0hrs on the clock. A groaning noise from the transaxle about a week ago prompted me to do an online search for information regarding the transmission.

[... Lots of great information omitted for brevity ...]

Thanks to all that have added to the body of knowledge regarding these units.
andrew

Greatest. Post. Ever. Thanks for the fantastic read.
 
   / TuffTorq K46 Repair Guide with Pictures #526  
Good afternoon,

Thanks for the feedback !

I`ll try loading the photos again, I may have tried to transmit to many Megs.

andrew DSCN0368.jpgDSCN0373.jpg
 
   / TuffTorq K46 Repair Guide with Pictures #527  
Ok, it seems as if I don`t try to do too many photos at once
then they will load.

Please see the previous post for the photo reference.

Thanks again, andrewDSCN0376.jpgDSCN0377.jpgDSCN0378.jpg
 
   / TuffTorq K46 Repair Guide with Pictures #528  
Thanks again. And plenty o' pooky. :) Should seal. What kind of RTV did you use? Almost looks like a polyurethane sealer called sikaflex.

Did anyone ever tell you that machinists purposely put shavings into the shop rags to get back at the mechanics that fill them with RTV silicone? :)

How thick were your shims by the way?
 
   / TuffTorq K46 Repair Guide with Pictures #529  
Ha !

Yes, assembled the day after Super Bowl.
That reminds me of the old comment about not buying a Chevy that was built on a Monday, (sleepy workers)
or a DSCN0374.jpgDSCN0375.jpg Friday, (payday distraction).
Photo 1 Closeup of intermediate shaft shim. This shim contains the end play of the shaft itself and holds the factory
shim, (the thicker of the two washers in the picture) in close proximity to the intermediate gear.
This shim also promotes the full alignment of the intermediate gear and the hydromotor pinion drive gear.
Looking through the holes in the intermediate gear the circumference of the "inside" intermediate gear shim can
be seen. The inside shim contains the movement of the gear on the shaft from "slapping" back and forth on the shaft.
Photo 2 Closeup of the shim on the driveshaft which sets the driveshaft pinion gear in position to contain the spider gears
within the differential gear in the proper position and also remove the excessive end play dimension to contain the
large differential gear from "wobbling" on the shaft. If you observe you can see the factory end play shims, (the "horseshoe" shaped shims)
which are apparently not measured and fitted at the factory to take up the differential gearing shaft end play.
All of the differential gearing, (spiders/spider shims, driveshaft pinions, and the differential gear itself), all "jingle" around on the shaft in a form
manner that I have only observed on high mileage, 400k+ diesel truck transmissions.

As a side note going back to the comments regarding the cleaning and flushing of the units while
being serviced.
The technique that I used was to rotate the transmission in the work stand until the gearcase mating
surface was vertical and even a bit past vertical to allow the flushing fluid to flow out.
Hold the intermediate shaft with the thumb of the right hand so it doesn`t fall out, (or remove it, easily done) while holding the unit steady and then with
the left hand spray out the interior of the unit with Jet Spray Carburetor Cleaner.
The old oil is instantly liquified and the carb spray actually "leaches" the old oil and metal particles out of the
pores of the metal case. The fluid will run clean out of the unit when all of the debris and old oil has been removed.
The change in the color of the fluid flowing out of the case is easily observed.
This method is fast, easy, does the best job of leaving the metal pristine and clean, ready for the application of the
gasket sealer. The carb spray will dry out of the metal within five minutes so no waiting to move forward and
no need to spend a lot of time or any time in that sense digging out the "nooks and crannies".
andrew
 
   / TuffTorq K46 Repair Guide with Pictures #530  
I thought the same thing when I just replaced my spider gears...Then I thought when the cover was in place it would tighten everything on all the shafts and space would not be so apparent. Wish I had thought to shim it.....shim it!!!
 
 
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