Drive Motors

I've wondered for a while, but never really had anyone be able to explain to me, how the planetary drives work. Is it basically a hydraulic motor with a set of planetary gears 'wrapped' around it?

I also seem to hear different views of how often to change, and what type of lubricant should be used. Is there a 'general' rule of thumb on this?

very hard to explane how they work but basicly its a gear box that dosn't change gears / i proberly could explan it to u but it would be easyer to grab a work shop maual and read that first ie very complex

inreguard to how oftern to change oil in finnel drive is very easy the w/shop manual recomend 250hrs but keep in mind every job u do is different. in one
day u might do alot of traveling and the next day very little thery being how mutch is your machine doing per 250hrs of working a simple rule of changing the oil is open oil plug check colour of oil if dirty looking change if it still looks like new oil leave it //it is chepper to change oil than to rebuilb finnel drives//
so my anser is it;s all up to u
u also ??? witch oil is preferable 80/90gear oil/ warmer conditions engine oil will also do the job/ie somtimes prefered in cooler conditions

cheers got to go my kangaroo is hungry

Planatary gears give you a stronger gear set up in a smaller pachage with the old bull gears they were huge heavy and you had 1 tooth at a time making contact. with a planatary you have 3 or 4 teeth making full contact in a smaller pakage. also buy locking the outer hub you create a reverse force like in a tranny.

how often also depends on if you are in mud and water a lot to. nice chocolate milk colored oil is never good left in for a long time

As mentioned beforeyou get more tooth contact with a planetary set up.
The motor engages a spline and then turns the planetary set up, it allows for greater torque, and better efficiency. Oil sampling can give you an idea of decreased oil change intervals depending on your working condition (lots of travel VS lots of digging with minimal travel) the environment would have more of an effect on the undercarriage wear items, if the torque hubs and motor are sealed correctly then nothing is getting in the caseing and therefore won't matter in reguards to fluid change intervals.