I recently went with larger wheels and tires and I want to regear the rearend. My mechanic said that since my T4R has 210K miles, he suggests replacing the rear axle's seals and bearings while he's already working on the rearend. Is replacing the seals and bearings too early for the miles it has? It's not leaking. How many miles does the rear axle go through before it starts to leak? All my driving has been on streets. No offroading.