TGB Blade 250 ATV Quad Service Repair Manual, Page 108Get this manual
9FINAL DRIVING MECHANISM Check if the reverse shaft is wear or damage
Check if the final shaft and gear are burn, wear or damage
Check bearings on gear box and gear box coverRotate each bearing's inner ring with fingersCheck if bearings can be turned in smooth and silent, and also check if bearing outer ring is mounted on gear tightlyIf bearing rotation is uneven, noising, or loose bearing mounted, then replace itCheck oil seal for wear or damage, and replace it if necessary