Cub Cadet Hydrostatic oil substitute

Joined
Jul 17, 2006
Messages
614
Location
SW Michigan, near Fennville
Got out our Cub Cadet XT1 Enduro Series and notice a oil spill under the rear of the lawn tractor (mower). Once I got it backed out I let it sit for several days and when trying to move it while running it barely moved forward and very little in reverse. Oil had leaked from the "Hydrostatic Transmission" and is sealed at the factory and not a owner serviceable (as in add oil) unit. You cannot check or change the oil and is designed for the life of the unit. Some life! Bought it June 3, 2015 and so not yet 3 years old (which might be withing it's warranty period. I took out the battery and one of the brackets and low and behold on the left side is a cap. Got the cap off and I was able to look right down into the trans-axle. Only thing I had that looked like it might be compatible for a Hyrdostatic drive was my Honda CR-V, Genuine Honda Fluid 08798-9031 Manual Transmission Fluid. Our Honda CR-V is a 5 speed stick shift 2002 light RV. So the transmission oil is not transmission 90W or anything like ATF.

I added about 1-2 cups of this Honda oil, replaced the cap and "what do you know" I was able to move it like normal again. I am scheduled to take it to the Cub Cadet service center to have this apparent leaking seal fixed. BUT was wondering if any of you have heard exactly what type of oil is in these Hydrostatic Transmission on the MTD Cub Cadet lawn mower tractors??
 
Transmission is a Tuff Torq K46, I believe.

Fill from factory was 10w-30, however Tuff Torq now says use 5w-50.

5w-50 is hard to find, so most people use Mobil 1 15w-50 or NAPA 15w-50...
 
mattwithcats is right on. My older stuff's manual said to use 10w-30 but it has since changed. TT now recommends heavier weight oils for the most parts. You gotta find out which transmission you have. Then simply call TT or go online and search. I have mowers using K61 and K62 transmissions and I use Amsoil Zero Turn Hydrostatic fluid 20w-50 in both of mine. Really quieted them down. IF I remember correctly, some of the TT transmissions still call for lighter weight oils. But like I stated earlier, most moved up to thicker weight. I only use my mower to mow and it's between 50-100 degrees when being used.

I change my fluid every other year.
 
I found the little plug on top and using a funnel put a little bit of this HONDA Manual Transmission oil in there. Here is the link. https://www.amazon.com/dp/B001IWL1O8/?co...lv_ov_lig_dp_it Curious how compatible this is to what was in there and leaked out.

s-l300.jpg
 
Last edited:
I would top it off with 15w40 or 20w50 motor oil.

FWIW, I was in line behind a guy at Advance Auto the other day who had a late model Cub Cadet riding mower with an axle seal leak. It's still under warranty, but the guy didn't want to wait to have it fixed. The counter guy sold him a bottle of 75w90 gear oil.
shocked.gif
 
Originally Posted By: Nebraskan
I found the little plug on top and using a funnel put a little bit of this HONDA Manual Transmission oil in there. Here is the link. https://www.amazon.com/dp/B001IWL1O8/?co...lv_ov_lig_dp_it Curious how compatible this is to what was in there and leaked out.

s-l300.jpg




It shouldn't be an issue other than lowering the oil's viscosity and causing the leak to get worse, but I would get the correct fill in there as soon as I could. I got the 5w-50 oil for my Cub from Napa, https://www.napaonline.com/en/p/MCL122075
 
Originally Posted By: mattwithcats
Transmission is a Tuff Torq K46, I believe.

Fill from factory was 10w-30, however Tuff Torq now says use 5w-50.

5w-50 is hard to find, so most people use Mobil 1 15w-50 or NAPA 15w-50...


Yup, according to the Tuff Torque rep, they now recommend 5w50. I'd use a 5w50 or 15w50 and you should be set. I filled the K66 in my Deere with Castrol Edge 5w50 and it has been working pretty good since. The transmission seemed a tad bit more responsive after the change and was definitely quieter. It had a significant whine when mowing up hill before the change, and the fluid that came out was pretty nasty at 350 hours.
 
I have a K46 in a John Deere and and as others have said, TuffTorq now says use 5W-50 synthetic. That what I did when I changed mine. I followed the procedure I found online.
 
Originally Posted By: Nebraskan
This hydrostatic transmission doesn't have a drain plug on the bottom.


None of the cheap mowers do. You have to take the trans out and turn it over to drain from the fill plug, OR use a mighty vac if you can get to it. Sounds like you can if you have a mighty vac.

If it’s a k46 have 2 qts handy to fill it back up, clean the magnet under the full plug.
 
Originally Posted By: racinjason
Originally Posted By: Nebraskan
This hydrostatic transmission doesn't have a drain plug on the bottom.


None of the cheap mowers do. You have to take the trans out and turn it over to drain from the fill plug, OR use a mighty vac if you can get to it. Sounds like you can if you have a mighty vac.

If it’s a k46 have 2 qts handy to fill it back up, clean the magnet under the full plug.



I only plan on taking out my Cub's trans-axle one time and that's to drill and tap the lower housing for drain plugs. I'll have about 50 hours on it by the end of this season so that's long enough for the factory fill to stay in. I thought about using a vac to do it but that only gets out less than half the oil from what I've read. Here's a pic with the port locations if anyone is interested.

 
Last edited:
I haven’t vacuumed a k46 because the gas tank is always in the way and typically dump them, the super cheap hydro gear rears(I e like a Troy Bilt horse) I get 2 qts out with a mighty vac.

A k46 may have something in the way to prevent full vacuuming.
 
Hey guys, new member. Sorry to revive an old thread but what is the proper fluid for these Cub mowers like the OP mentioned? I’m pretty sure I have the same tractor which is the Cub Cadet XT1 LT46 and the model number is 13APA1CT009. My local tractor supply has some Cub Cadet drive system fluid plus synthetic blend oil for what I’m assuming is for that but when I go on Cub Cadets website, search for this very same oil and then enter my tractors model number under the part where it says it makes sure that said part will work with your equipment, it says this oil won’t work with it. They also have some BadBoy oil for a transaxle but it’s a 20W50 oil. This stuff doesn’t even say what it is so should I just take a chance on it or what? Thanks.
 
Back
Top