bigsteve, I have had good luck with my workplace Gators (regular 4x2) following the recommendations in their manual. They are available (full version) at the JD website:
http://www.deere.com/en_US/ProductCatalo...g=off&tM=HO
I find John Deere owners manuals to be somewhat inconsistent and sometimes wrong in their maintenance recommendations. I have found wrong filter numbers, capacities, etc.. Sometimes the intervals are goofy. Be careful.
One goofy recommendation is for spark plugs....every 200 hours or annually (whichever is first)....sparkplugs won't go bad (timewise)if you only put 50 hrs. on it in one year.
Your manual (gas engine?) indicates it is water cooled and 10w30 looks correct (they show 5w30/10w30/10w40). Gators tend to do lots of short runs, start/stops, etc.. I like the 10w30.
They list 800 hrs. or 2years (whichever is first) for the transaxle and front differential. I do ours every two years....800 hrs. in two years is insane. I have found some moisture from condensation in these components if I go longer, but that will vary according to conditions.
Which lube for the transaxle and differential. This one is goofy...go to the appropriate manual section.
Transaxle: they "recommend" the JD J20C Hygard but say the low viscosity JD J20D "may" be used if within the temp charts.
Front differential: They only "recommend" the low viscosity J20D here. Only a few other manufacturers list the J20D spec. and it is hard to find.
I use the JD products for ease of availability. Many products meet the J20C spec.
Here's the link to the transaxle/differential manual page:
http://manuals.deere.com/cceomview/OMM157849_A9/Output/Index.html?tM=HO (this link only takes you to the manual, you will have to click on the left to get to the tranny fluid section)
Please confirm all information for yourself....I don't know which exact model/production series you have.