I want to rotate my tires on a 1999 DII. Do the lug nut covers come off separately or with the actual lug nut? Can you use an imoact wrench to take these off? Thanks!

Phil

 

No the caps are designed to stay on. If you have been using an impact wrench you may have ruined them, and they are expensive.
Use a breaker bar with the correct size socket, I use a 1 1/16th. 6 point socket and torques mine to 102 foot pounds.
As for rotating, go front to rear and run all your tires at the same air pressure, I run 40 pounds of air.

 

Do you see improved performance running 40 pounds of air? I have been running the recommended 28 front 46 rear.

 

Those specs. from the factory, are to give you a comfortable ride, not insure better mileage, tread life. If you measure the height of both tires, with a load on them, I believe you will find a difference which when the CDL and or lockers are engaged will cause an uneven strain on the drive train.
Running 40 pounds, I find I get a more even tire wear, only rotate them every 20,000 miles. I have also found that running higher air pressure, in my case 40 pounds, gives me nearly 1 more MPG.
So yes, I advise everyone to consider running higher, even air pressure in their tires.

 

I also run them at 40 psi. Forget about the 28 front 46 rear thing. I used to go by that but realized that I had more even tread wear with the 40 psi all around.

 

You'll also note that the owners manual does not say 46 psi for the rears, unless at max weight. It says 38 psi, which is a lot closer to the 40 psi that a lot of people recommend.

 

I rotate my tires everytime I drive.

 

I think its 46 psi rear if you have air suspension regardless of weight.

 

All of the stickers say 46. But if you look in the owners manual you'll see it says 38.

 

SLS does not require more air pressure unless you throw more the 1000 pounds in the cargo are, then air up based on your tire/side wall rating.