I did mine much earlier than 80K miles. I remember the first tme I did it was not easy to them off. I guess, just soak it with more Liquid Wrench or whatever. The bolt on the diff is easier since you have more room to work and see better. I actually use the correct size (big) size (not remember the size) on this one. For the transmission, you just has to let the soaking to do the work for you. I too used the box wrench and took great care not to round this sucker or you will be sorry! Good luck!