Just replace the crush sleeve, pinion seal, and reset the pinion bearing preload to specs with an inch;lbs. torque wrench. Thats if everything else is okay. Hope you are aware that you will need the correct tool to hold the pinion flange while you tighten the pinion nut. Please do not use a monkey wrench. Mancini racing has the correct tool that attaches to the pinion yoke for about $25. Ive used it to set up mine. Make sure you go very slow when you tighten the pinion nut. Its very easy to overtighten and have too much preload. The method that worked for me is to tighten the pinion nut, check preload, tighten, check preload. It takes a lot of patience but its worth it. You will have to replace the crush sleeve if you overtighten. Dont ask me how I know.