im trying to put 4.88's in my tj.my stepfather is a very good mechanic but hes says we dont have the right tools to properly regear it/set the backlash.what tools are needed that arnt in a average shop?ive heard if you use the factory pinion washer/spacer the teeth will be close enough that it wont hurt anything.is this true?thanks  

hey there is a really good blog on the internet  Free Automotive Differential Ring and Pinion Gear Installation Instructions
Free Automotive Differential Ring and Pinion Gear Installation Instructions plus Online catalog for cars and pickup trucks parts at discounted prices, you save money!
www.drivetrain.com/ringpinioninstal.html - 29k - Cached
check it out it convenced me to get a shop to do my and let them have the headacke!!!!!!