I know - look in the mirror!

2005 Ram 1500 with Hemi 2wd. Which rear end would this have or better yet which viscosity gear oil am I supposed to use?

 

9.25 corp rear.

 

Most fool proof way is to go to (or call) your dealer and give them your VIN. Your operators manual will list what grade of oil you need. I am fairly certain you have the same rear end as the 4x4 Trucks have. In which case you need Synthetic 75W140. But double check first. A decent auto parts store could likley figure it out as well.

 

Yep, ALL 3rd Gen, non Mega Cab 1500s have the Chrysler Corporate (AAM) 9.25", 12 bolt, 31 spline rear ends...

 

Thanks all. Royal Purple 75W-140 it is.

 

Don't forget the friction modifier if you have LSD.

 

A review worth reading:

http://www.syntheticoilhq.com/gearoi...risontest.html

If you click the PDF attached to it, some great info. Certainly not gospel, but might make you think twice about spending the extra money (at my local shop, a difference of $9.00 per bottle) on Royal Purple over Mobil 1 or Valvoline.

Just don't get caught up the hype that more expensive = better protection. Simply not true. And quite frankly, if you change your gear oil every 30k like they want you to, you coudl buy most any brand of gear oil that meets the specs and have nothing to worry about. I have yet to see or hear of a properly maintained differential that used the correct spec oil that failed because of the BRAND of Gear oil they used.

 

I have Royal Purple in my front diff, Valvoline SynPower in my crankcase and Lucas conventional in the rear diff since my Auburn Gear LSD is adamant about wanting conventional lube and Mopar fluid in my transmission and transfer case.

I am not really into one brand over another but I will say I've been associated with a very high end performance shop who regularly had top track Mopar vehicles and a couple of 4x4 shops (I mean like ran vehicles in off-road races and professional off-road competitions) and in each of those shops the preferred lubricant was Royal Purple. Just an observation. BTW back in those days I was running Mobil 1 in everything I had...