Tuff Torq K46 oil question

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After the usual searches I found the factory units on most mowers used a 10w30 oil in them and Tuff Torq recommends a synthetic 50 weight motor oil for best function. I was looking at several threads on other sites regarding failures of the unit. I was thinking this thing needs an oil with some sort of EP additive to give it a fighting chance. I cannot find any info on using a hypoid gear oil in it. I emailed Tuff Torq about the compatibility of hypoid gear oil and they just advised me that 50 weight motor oil is the best due to viscosity. Nothing else.

I checked the viscosity chart and find that a 50 weight motor oil sits [censored] near where a 90 weight gear oil is.

Any thoughts?
 
I changed the factory fill in my TT K61 to Mobil1 15w50 about 8 years ago, and it's still going strong.
 
Both Hydro Gear and Tuff Torq all specify using an API rated motor oil these days. Don't know why.
 
Originally Posted By: BrianF
After the usual searches I found the factory units on most mowers used a 10w30 oil in them and Tuff Torq recommends a synthetic 50 weight motor oil for best function. I was looking at several threads on other sites regarding failures of the unit. I was thinking this thing needs an oil with some sort of EP additive to give it a fighting chance. I cannot find any info on using a hypoid gear oil in it. I emailed Tuff Torq about the compatibility of hypoid gear oil and they just advised me that 50 weight motor oil is the best due to viscosity. Nothing else.

I checked the viscosity chart and find that a 50 weight motor oil sits [censored] near where a 90 weight gear oil is.

Any thoughts?


I got the same response. Installed 15w-50 M1 and my TT46 is as quiet as a mouse, seems very happy...
 
i drained my k46 and refilled with GC 0W30. so far, much quieter and smoother. i think any synthetic oil is an improvement over mineral oil in these things.
 
I wish I could change mine, alas Cub Cadet says its sealed from the factory and cannot be changed. Haven't looked real close but she does whine something good.
 
Originally Posted By: Oli20
I wish I could change mine, alas Cub Cadet says its sealed from the factory and cannot be changed. Haven't looked real close but she does whine something good.


I did have to remove the unit. It's not very hard. There's a magnet to clean, too...
 
I think I will split my transaxle when I do the oil change. I see there is another magnet inside, near the gears. Would be nice to inspect and clean as well. I have no problems switching to a 50 weight synthetic oil. I have no issues with this and don't think I will test if a 90 weight gear oil works.

Oli20: you have to remove the unit, pop the fill cap and turn upside down to drain. Then refill both chambers, purge the air and install.

I was thinking of installing some drain plugs as per Tuff Torq, although you could then easily drain it but you still would have tight access trying to fill. I have no urge to butcher the steel panels to gain an easier fill location.
 
i have a cub cadet lt 1046 with the hydro gear trans. it has the drain plug, but ya cant get to the stinkin fill plug! and its harder to drop the trans in this one. the deere is much easier.
 
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I just did the tear down of my k46. Was in decent shape. The original oil was medium brown in color and the magnets, all 4 of them had a little fuzz but nothing serious in my opinion. The hardest part of the tear down was cleaning the FIP gasket material off the somewhat rough cast surfaces. That and re-installing the bypass rod on the tractor.

I used Motomaster Formula 1 synthetic 5w50, which is some sort of rebadged Shell product. Once I filled the unit I tipped it around, turned the pulley numerous times and watched a few air bubbles come out. Did a quick purge on it once installed and away she went. It runs about the same while cold and the hydro whine is all but gone.

Was actually a pretty easy process I must say.
 
Originally Posted By: BrianF
I just did the tear down of my k46. Was in decent shape. The original oil was medium brown in color and the magnets, all 4 of them had a little fuzz but nothing serious in my opinion. The hardest part of the tear down was cleaning the FIP gasket material off the somewhat rough cast surfaces. That and re-installing the bypass rod on the tractor.

I used Motomaster Formula 1 synthetic 5w50, which is some sort of rebadged Shell product. Once I filled the unit I tipped it around, turned the pulley numerous times and watched a few air bubbles come out. Did a quick purge on it once installed and away she went. It runs about the same while cold and the hydro whine is all but gone.

Was actually a pretty easy process I must say.


It's not a terribly challenging process for sure, just take your time and some pictures of how things went together before tearing them apart.

When I had mine split I replaced magnets, internal filters, added the magnet bracket to the internals, resealed and assembled then filled with Syntec 5w50 and purged.

Runs better than when I got it going on 4 years after I serviced it.
 
Originally Posted By: NewYorkBuck
In my Tuff Torq I use Amsoil 20W-50. Seems happy.



Mine,too.
 
Since the change mine has been running like a top. Even with the trans heated up it still has enough juice to spin the tires at times. Just found the fan was half broken as well. Have to get a one ordered.
 
I've done mine twice, the first time with Castrol 5W-50 and the second time with Quaker State UD 5W-50 that was on sale for $1. At 360 hours it is working well. When I changed it last month for the second time, I also changed the transmission drive pulley as there was a ton of play in the splines.
 
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There are no hypoid gears so you done use a "gear oil"

m1 15w50 or whatever you want really.
 
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