I've got my dealer telling me the interval for changing the rear differential lube is every 15,000 miles on my 2008 Ram 1500. Anybody know if this is true? I find this hard to believe - I'm more accustomed to 60,000 mile change intervals as the norm.

I think they want the cover pulled frequently so the rear end can be inspected. Evidently those rear ends have a lot of early failures.

I think it is a recommendation. If you have the anti-spin differential I would change it more often since that setup in these trucks have more issues anyways and you want to make sure you don't have anything floating around.

I changed mine at 50k miles but, keep in mind I've had the truck since new so I haven't done any real hard driving mostly highway plus a 3.55 open rear. Haven't noticed anything thus far knock on metal.

They changed mine at 15K when they changed the ring and pinion for noise issues I changed it again at 45k...it has 55k on it now. Mine's an 04. I put in reg gear oil...they call for a syn lube that seems real thin when you drain it

P.S Mine is also a 3:55 open

I believe the synthetic recommendation is to get the maximum possible tow rating with the 9 1/4. It holds up to high temps better. If you are not towing heavy loads, standard oil is probably OK.

My 04 2500 is the same way, 15k on both diffs using synthetic. Good thing is the gasket is reusable rubber with metal core & it gives you a chance to check out the diff. Lot of prob with bearings & ring & pinions. I believe there is a TSB out on diff noise. I use mobile 1 & just turned over 62k with no problems.

Doesnt ANYONE read their owners manual anymore?

When my kid changes the fluid in his 04 Hemi Ram he just gets the Mopar fluid.Changed it at 15K the first time and at 40 K.Its due again.He figured for the cost its cheap insurance.His truck is driven pretty hard and is a SG.Rocky

On my 1995 I changed to Mobil One Syn 90W at 18,000 miles on the open (no anti-spin) 9.25,
then changed it again at 40,000 with Mobil One Syn 90W,
and yet the 9.25 differential was howling so bad at 60,000 miles
that it was torn down and the
pinion bearings,
seals,
ring and pinion and
a re-designed nut with pre-applied factory white Locktite paste was used,
but the differential failed again at 140,000 miles,
even with gear oil changes every 20,000 miles.

Throughout the 1990s Chrysler had problems with the 9.25 that were not present in the late 1980s,
and I have not seen any evidence yet that the root problem has been solved,
even after the independent company American Axle entered the supply train picture.

My guesses:
either the "crush sleeve", or
the locking method to hold torque setting for the big nut,
... are the root of the problem