Changed out the rear differential oil today on the 555E. It came out as black as used motor oil. The manual calls for NH134D which is a hydraulic oil, but I’ve never seen hydraulic oil turn the color, consistency, and look of used motor oil. Anyone have this happen before? The machine has 4200 hours on it but I didn’t think hydraulic oil could turn this way. With everything I’ve said, I’m assuming no one has ever changed the oil prior to me buying it and that it’s original OEM oil from the factory.
I believe that spec is hygard hytran multipurpose tractor oil I've seen it like that from being ran way longer then it should or the brakes cooking it
More than likely, the axle has wet brakes inside. Age, and wear perhaps
Definitely a wet brake system.
Does it smell burnt
Honestly I didn’t smell it. Just felt and looked like used motor oil.
I would have never thought, but changing the oil has completely eliminated my brake chatter. Ran the machine for 8 hrs today and it didn’t make a peep. Prior to, when it was warm and I used the brakes, I thought I was going to rip the rear end out.
Oil has a major effect on wet brake performance both actual braking and noise. some machines use a friction modifier additive to help the brakes as well. do check your brake discs if possible through an inspection port or indicator. You don’t want them to wear the friction material off and start grinding into the steel discs it goes from a simple replace seals and discs to rebearing and replace damaged parts very quickly.
Dirty oil or the wrong oil definitely makes trouble for the wet brakes. We had a place that was putting aw68 hydro in all their tractor rears, they made all kinds of noise lol.