Should I change the trans oil?

[motox25 36]

I just picked up a used 91 520H with 320 hours on the hobbs, not sure if its accurate.  I planned on changing the trans filter but there seems to be differing opinion on whether or not to change the trans fluid.  I am leaning towards changing it because I have no knowledge of what is in there, but the tractor seems to drive fine at the moment, the hydraulics are also working.  Also, is it a good idea to change the fluid every couple of years?  I was planning on putting Mobil1 10W-30 in there unless there is a better oil.  Thanks!

[Hodge71 664]

Absolutely!!! Change the oil and the filter at the same time. Mobil 1 10w-30 will be just fine. There are people on here that swear that you need to change it every year. I can tell you from experience with a 1973 12 Auto that my Dad has since new. He changes the filter every year and adds to make up the difference til full. The oil gets changed every other year or so. It has over 4000 hours on it ( now thats a long term reliability test) and he's been using Castol since he got the tractor in '73 with no loss of power or reliability. Mobil 1 being a full synthetic should protect better than regular dino juice if you believe the claims.  

[varosd 1,185]

I change to hydro trans oil and filter every 6 months  certainly the change in the color of engine motor oil and hours dictate changing both oengine oil/filter a lot.  while the tranny oil looks fine, I suspect the tiny metal fragments from the gears are suspended and while the filter is there to catch theses particles,  might be overkill to change frequently but small price to keep the Eaton tranny happy!

[JackC 617]

Absolutely!!! Change the oil and the filter at the same time. Mobil 1 10w-30 will be just fine. There are people on here that swear that you need to change it every year. I can tell you from experience with a 1973 12 Auto that my Dad has since new. He changes the filter every year and adds to make up the difference til full. The oil gets changed every other year or so. It has over 4000 hours on it ( now thats a long term reliability test) and he's been using Castol since he got the tractor in '73 with no loss of power or reliability. Mobil 1 being a full synthetic should protect better than regular dino juice if you believe the claims.  

 

4000 hours?  Is that for both the engine and the tranny?  Amazing if it is.

[zanepetty 117]

I'm no wheel horse expert but I would say definitely change the oil. That can only be good for it. Enjoy you're new tractor!

[Hodge71 664]

 

Absolutely!!! Change the oil and the filter at the same time. Mobil 1 10w-30 will be just fine. There are people on here that swear that you need to change it every year. I can tell you from experience with a 1973 12 Auto that my Dad has since new. He changes the filter every year and adds to make up the difference til full. The oil gets changed every other year or so. It has over 4000 hours on it ( now thats a long term reliability test) and he's been using Castol since he got the tractor in '73 with no loss of power or reliability. Mobil 1 being a full synthetic should protect better than regular dino juice if you believe the claims.  

 

4000 hours?  Is that for both the engine and the tranny?  Amazing if it is.

 

Why is that amazing Jack? These are great engines that Kohler made. The only thing ever done to it was hardened valve seats in 1978 when it lost the exhaust seat. My Dad still has the repair receipt...$108 with tax....Lotsa money back then...lol.... My father has been using this machine to mow his acre and a quarter every week plus till the garden every spring until he stopped planting. We also used it to plow his 300 foot long driveway in the winter. From 73 thru 2001 we had the factory lawn vacuum on it, but now he just lets the clippings lay with my 48" deck from my 416. This tractor has been garage kept and well taken care of its whole life. It shows its age but still looks pretty good for a 40 year old machine with original paint. It still has the original Nelson muffler on it to boot.

[zanepetty 117]

That's great to hear. I like seeing machines get well taken care of!