How to change the trains fluid in a 856 unidirectional 3 speed

[Matt856 2]

Can you please provide me with a detailed description on how to change the trains fluid on my unidrive 3 speed. I'm new to this tractor and just want to be exactly sure on what I'm doing. Also, what fluid should I be using, 90wt? 

Thank you! 

[rmaynard 14,918]

On the bottom of the transmission is a drain plug. It is usually flush with the surface. It uses a 1/4" Allen wrench to remove it. The plug is just in front of and to the left of the front tang if the draw bar hitch. Usually covered with grass, dirt, and oil, it is hard to see.

1-1/2 qts. of 90-140 GL-5 gear lube is what's called for, but 80/90 w. gear oil is fine. That is assuming that you have emptied all the old fluid out. The older transmissions don't have a dip stick, so adding the correct amount is not an exact science. Don't use the plug on the side as it will not allow you to add the entire 1-1/2 qts. I fill through the shifter hole.

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[953 nut 51,826]

       Bob gave you the easiest way on earth to fill a Unidrive. To remove the shifter you will have to pull off the rubber boot on the shifter, back off the lock nut on the set bolt at the front of the shifter a little and lift the lever out. When you reinstall it be sure the setscrew is in the dimple on the swivel ball.

[Ed Kennell 35,892]

                                                                              and
       I also like to flush mine by filling with kerosene or diesel fuel  and running it slowly thru each gear for several minutes.  If the oil is really dirty or foamy indicating it had water in it, I may flush it several times before filling with the gear oil.
                                         

[Matt856 2]

Thanks! I saw the drain plug and was positive that's how I drained it, but I was unsure if I should use the fill plug on the side, or the shifter. I know everyone likes pics, so here is the first one I've taken. I put new tires on the back and cleaned up the wheels while I was at it! I'm planning to troll every thread of this forum for ideas. Thanks again! 

[Ed Kennell 35,892]

   Great looker....Nice job on the rear gummys.  What are your plans for this gem.

[Racinbob 10,299]

There's a hump in the center of the tranny that will trap oil in front of it. I raise the front of the tractor to get all the oil out.

[Matt856 2]

@ekennell I'm going to try my best to restore it. It runs pretty good, so I guess it's mainly cosmetic. After that I'm gonna use it! I've got a deck and a plow that I'll try to fix up as well 

[Ed Kennell 35,892]

Keep us posted on the progress Matt. 

[KC9KAS 4,741]

@Matt856
I recently cleaned the lube out of a C-120. I actually had to "flush" it 2 times to get it clean. I used kerosene, and elevated the front and let it drain (each time) overnight.

Edited October 5, 2015 by KC9KAS