New here, I've got a 856 and need to change the Trans oil.

[CS-17 13]

Howdy, I'm new here. I wanted to see if anyone new what the current recommendation is for transmission fluid/oil in a 856 Wheel Horse.

The manual says " A good grade of S.A.E. 40". Does this mean SAE 40 Motor oil? Is this still the best oil for it or is there a Better option?

Thanks in advanced for recommendations!

[rmaynard 16,167]

I think 40W was recommended at the time, but I use 85/140 GL5 gear oil. My 856 ran fine with it.

[peter lena 9,184]

@CS-17 agree with @rmaynard  on the oil , think that initial drainage , is the perfect  opportunity , to FLUSH OUT AND  remove existing crud , moisture etc , have any  good road driving in your area ?  have  CUL DE SACS , near me , like to use hi mileage , atf fluid , kerosene , as a cleaner , use every gear , forward / reverse , picture the lighter  oil , spraying down the entire  inner case , of debris , moisture etc . put some time on it . new shift boot , elevated front end to ensure , drainage . regularly bring a tool bag on a road test , penetrating oil , carb cleaner , plyers , screwdrivers  etc , good opportunity to get to know your unit . also  get some penetrating oil on every related . MOVEMENT POINT , on the clutch linkage , usually  solid rust bound , once moving I like red aerosol spray grease  , tube extension , for pin point application , penetrating oil  on / in every cable movement area , should move with ease .  things I regularly do , welcome , pete

[Racinbob 11,875]

17 hours ago, CS-17 said:

Howdy, I'm new here. I wanted to see if anyone new what the current recommendation is for transmission fluid/oil in a 856 Wheel Horse.

The manual says " A good grade of S.A.E. 40". Does this mean SAE 40 Motor oil? Is this still the best oil for it or is there a Better option?

Thanks in advanced for recommendations!

 The early years of the two piece Uni-Drive had an issue partially caused by suction holding up the shift rails as you shifted causing it to lock up in two gears. As the engineers were trying to solve the issue one of the things they suggested was going to 40w oil to lessen the suction effect. They issued a service bulletin on it and it made it in some of the owners manuals. Shortly after that they came up with a reliable mechanical fix and the lighter oil was no longer needed. It didn't get emoved from all the owners manuals. Providing you have an original 5053 transmission you have the mechanical fix and don't need the light stuff. I would suggest using a good 80w90 +/- but you won't hurt a thing with the 40w.

[CS-17 13]

Thanks for your reply! I have one more question, what is the best liquid to clean the trans before putting new oil in? Diesel, Kerosene....

[adsm08 2,941]

24 minutes ago, CS-17 said:

Diesel, Kerosene....

 

These are basically the same thing.

[oliver2-44 10,553]

Eitherone will work fine. 

[953 nut 59,143]

I have been using SAE 40 non-detergent in my 1055 for years without any problems.   If this were an Indianapolis 500 race car it probably wouldn't be adequate, but for a garden tractor going less than 5 MPH it is fine.

[HyperPete 787]

16 hours ago, adsm08 said:

 

These are basically the same thing.

 

And, what I used because it was handy, home heating oil (also the same except for red dye)

[oliver2-44 10,553]

Go to Wally World and get some store brand 80w90. It plenty good for these transmissions.  

[ebinmaine 71,756]

On 5/25/2025 at 12:30 PM, oliver2-44 said:

Go to Wally World and get some store brand 80w90. It plenty good for these transmissions.  

 

 

 

 

On 5/25/2025 at 7:58 AM, 953 nut said:

for a garden tractor going less than 5 MPH it is fine.

 

What if we hit 6.25 MPH??

[Horse Newbie 7,306]

9 hours ago, ebinmaine said:

 

 

 

 

 

What if we hit 6.25 MPH??

Add a transmission oil cooler…