i've had my truck since may and have just been using valvoline 10w-30 and a k&n filter, whats the best oil to use? i want to switch to synthetic and have been thinking about RP, and in about 15,000 mi its time to change my rear axle fluid, i love my truck and want to keep it nice and running good, i also plan on going with a CAI and some 2.5 duals with some 3in tips, when i get my payments down a little lower

 

Why is it time in 15kmi to change your rear diff fluid? How many miles you got? I always change fluids right away when I buy a used vehicle. The rear diff should be changed after only a few thousand miles which most people don't due, they wait until the 30 mark??? Theres more metal back there in a few thousand miles than your motor will shed in it's lifetime. My first diff change will be at 3kmi.(should really be done at 500 then at 3kmi, but lets get real..lol) My first oil change was done at 800miles and will be done again at 2kmi and then on a normal schedule after that.
10w-30 is fine for most weather conditions. You can do 5w-30 if your in the northeast like me for winter time.

 

Noop. Dodge schedule for rear and front diff's is every 15000 miles.
I agree about new fluids on a used truck though.
Al.

 

Castrol Full synthetic, weight depending on your climate and use, It goes in and out of my vehicles looking exactly the same.

 

5W20 is reccomended for the 5.7 Hemi. I use 5w20 Castrol Syntec.

 

According to the 2004 FSM, 5W30 is recommended for colder temps, 10W30 for warmer temps. The 5W20 is required for the MDS engines.

 

I have a 2005 Hemi 5.7 that doesn't have MDS and it calls for the 5W20.

 

i have 79xxx, and the manual says to change it at around 90,000 in the maintenance log book, i bought my truck at 72xxx miles and was just going by what the manual said, i need to look and see what the change date was for axel fluid before the 90,000 mile mark in the book