Ranger Smith.....before you replace, there is a vent on the top of the gearbox. On both my 2014 Dutch Star and 2019 Dutch Star, Freightliner used a 3" riser to lift that vent tube off of the box. On both of mine that vent tube puked oil. Eventually, the fix was to add a long hose, extending the vent tube about 18".
Looking at my friends 2011 Allegro Bus, I saw that they used the same gearbox, driven by a drive shaft. On my coaches, Freightliner determined it was a seal and replaced MANY seals under warranty, when it was NOT the seal, but the vent tube. If you looked really close on mine, you could see a little river flowing form the vent tube, down to the seal. The oil blows all over the fan blade and the engine.
Before you replace the gearbox, thoroughly clean the area with a degreaser and then spray it with a hose. Then determine f your leak is from the vent tube or the seal. There is a large nut on the top of the gearbox, if you remove it, it has a short dipstick attached to refill to the proper level.
