Originally Posted by KYHI

They make a shim/seal kit and a shim/bearing kit - the proper kit depends on the mileage, wear and tear on the axle..

At min - I would get the $30 shim and seal kit installation kit

And depending on your load you may want a little higher gearing - like 4.56
They also seem to be the gear ratio of preferred choice

You need to take into factor your towing RPM and Engine Torque / Horsepower ratings..

Here is results of a possible gear change on my truck.. And personally, I am comfortable driving my truck at 2600-3200 rpm at 70 mph

3.55 ratio - 32.8 tire height - speed 70 mph = OD 1782 rpm

3.90 ratio - 32.8 tire height - speed 70 mph = OD 1958 rpm

4.11 ratio - 32.8 tire height - speed 70 mph = OD 2063 rpm

4.56 ratio - 32.8 tire height - speed 70 mph = OD 2289 rpm

4.88 ratio - 32.8 tire height - speed 70 mph = OD 2450 rpm

Originally Posted by bdjordan

can I get away with just buying ring and pinion without the whole kit? That would only be around 400 or so in parts. The mechanic told me to get the whole kit??

Originally Posted by jasonw

I have been told that if you have over 30,000 miles on an axle, and you swap out ring and pinion, you'll need new bearings. Only get Timken bearings, the others don't seem to last.