I see a thread here today discussing the "favorite" oils to use when it comes time to drain and replace oil in the differentials.

Could someone who's now done it provide some guidance on the procedure, tools, difficulty, gotcha's, etc to doing the job? I'm at 15K and was going to have the dealer do it for me but if it's a pretty easy job I would do it myself.

Thanks in advance for the help.

 

I just did it this past Saturday on my 04 2500 4x4 at 6800 miles.

Rear end is really easy because it's up high....just unbolt cover (14mm bolts) and remove old fluid.. It took right at 4 quarts.

Frt was a little trickier (13mm bolts) due to the crossmember beam going across in frt of the cover. So, make sure you have a couple of universal-style sockets available..It took little over 3 quarts.

I used AMSOIL Series 2000 75-90w . Some people run REDLINE products....it's up to you...Driveline is alot quieter.

Oh, don't forget the OIL SIPHON at AUTOZONE or any boat store...to get the fresh oil in! MOving that 75-90w through a pumping mechanism will give your shoulders a workout, especially is you're laying under the truck like I was...

How do you like the 315's? 65pounds a tire is lot of tire to move. What has happened to your fuel mileage?

Good luck Commander.....

 

rossn2

Thanks for the quick reply.

So there's no drain plug? You have to pull the covers off? Do I need a gasket or just use RTV when I put them back on?

I don't have any fuel mileage to compare pre and post 315s to -- I drove from the dealership to the hobby shop at the base and swapped the tires before I ever had to fill up!! I've got 5 unused stock Michelins if someone wants to buy them!

Oops -- just saw a thread further down the list that answered my questions -- amazing what you can learn if you keep your mouth shut and just listen/read

 

what do you torque the bolts too when you put it back together?

 

Haven't done mine yet, but I understand that the gasket is reusable. No drain plug. Also, I think you coul get by by just loosing the cover and removing the bottom bolts..correct me if I'm wrong.

 

30 ft lbs. is what I've read on here. Again, correct me if I'm wrong.

 

Yes, gaskets are reuseable one-piece rubber...You could just loosen the covers, but you would never see if you have metal chunks laying in the case.

Torque applied, ONE CHIEF PETTY OFFICER leaning on a rachet held by a Commander!

 

do these cover have magnets in 'em for shavings like the danas?

 

Yes, the drain plug is magnetic for the fine stuff.....Since my rear end, transaxle, transmission were all low when I checked them BTW the dealer did first OLF at 3800 miles and it's the same dealership that told me "I had to buy the cold-weather package to get the cord for the block heater, and that's just a dummy plug in the side of engine, there's no block heater installed from Cummins, and we have to install it for you", I decided to look at the gears. No unusual wear....

Changing to synthetics did quite my driveline down....

Tonight changing engine to AMSOIL 15-40w....Stratapore filter going on. I'm at 7200 miles....

 

isn`t it a little eary to change over to synthetics in the crankcase? alot of threads here stating that move should be made closer to 15,000 miles

 

I'm not sure about the 2003 but the 2004 shop manual calls for synthetic lube in the differentials. That implies that they come that way from the factory.

Anyone know what the factory shop manual says for the 2003? The reason I ask is because people here are saying their ride is quiter after changing to synthetic but if the factory shop manual requires it then they are either not putting it in from the factory or people are hearing (or not hearing) things. I have noticed that my car runs better after washing it...LOL. Could be the same phenomenon.

Anyone know what year they switched over to the AAM axle?

 

The 2003's came with the "new" AAM's. Not sure about the 2002 3rd gen 1500 series. Factory fill is synthetic fluid 75W-90.

I didn't notice any difference in smoothness or noise when I replaced the fluids. But maybe some of those folks are experiencing a placebo effect - they want to hear that there is less gear noise with the new fluid.

 

F11-Using a 21/64 bit I drilled my covers bottom, off center [to clear gear] and tapped with a 1/8-27 NPT tap, drained and installed a 1/8" pipe plug. To do again I would go with a 1/2-13 or 1/2-20 magnatised auto pan drain plug. I did'nt have a 13 tap at the time.

Also, I read a spec sheet advising to only fill my 2001s diff to 5/8-3/4 below the fill plug, didn't say why? Any body know? STY

 

Anybody using 75W140 in their rear axle? I tow heavy and am thinking of switching to it. Truck is stored in winter so cold weather is not an issue. Appreciate any comments both pro and con from anyone that has tried it. Thinking of Redline 75W140NS synthetic.

Casey

 

Yes, they come from factory with synthetic 75-90w oil. I Mopar calls it GL-5 SAE 75w-90 Synthetic. I don't know what brand it is, I only know that Dealers aren't inspecting them during PREP and they are low from the factory...Maybe why so many people with 3.73's having problems with whines... I filled everything underneath up to where it starts coming out the filler holes...

Not worried about change interval...DC Maintenance book says ok after 5000 miles and Cummins homepage says after 5000-20k miles on engine.

And yes, drivetrain is quieter...NOT a placebo effect. Wife commented yesterday that she thought truck was quieter...