Hello everyone. I have a 420 that I bought last year. I serviced the tractor at that time except the mower gearbox. I noticed the PO had installed a grease fitting in place of the vent. The mower was quiet so I used it as it was planning to change the lubricant next season. It's now next season. The box seems pretty full of grease that will not drain. I am not sure if the po had a seal issue, or why he did this, but I feel like it isn't the best choice. I suppose I could run some kerosene thru it to try to wash the grease out, or should I just add more grease? Looking for members experience with this. Thanks.