John Deere 506 rotary cutter service question

[JD3520Turbo]

You don't ever want to fill a gearbox full. It has to to have room to sling and expand when hot. My HX 15 has little dip sticks on the top cap to tell you how much oil is in there. I have never changed it, and won't either. I check once a year, and top as necessary.

 

[Bigfoot62]

No drain plugs, but I've seen check plugs, usually half way up the gearbox to tell you how full to fill it. Most gearboxes only need to be 1/2 to 2/3 full, not completely up to the top.

The reason you usually don't have drain plugs is because you usually never have the change the oil. It doesn't get dirty and contaminated like engine oil. The original oil would likely last as long as the gearbox itself.

No, the reason that you don't have drain plugs is that the lower seal gives out and it drains itself. :laughing:

 

[sunnyside360]

No, the reason that you don't have drain plugs is that the lower seal gives out and it drains itself. :laughing:

Yep. Just replaced the lower seal on left gear box of my 3008 Bush Hog last week. What a PITA that was getting the stump jumper off the spindle. The 3008 cutter has 3 gear boxes, weighs almost a ton and has no drain plugs. Owner's Manual doesn't specify changing the oil but of course you have to when replacing the seals.