While at the dealership the other day, the service tech said that I needed to have my front and rear differentials serviced because I have 15,000 miles on my '06 2500.
I was a little surprised; he said it needs to be done every 15K.
Is this guy yanking my chain and trying to get $400 out of me or is this indeed true?

 

Your Owners Service Manual does in fact state that they need to be changed every 15k.

Personally I change the rear diff fluid every 30k and the front diff every 45k. I don't tow often, and my personal experience leads me to believe that 15k is overkill in my driving situations.

I do change mine at 15k miles on the odometer just to clean them out. After that, they are fine at the intervals stated above.

The diffs have reusable gaskets, so it is actually a very simple maintenance procedure. I can do mine in about an hour and it costs me about $65 in diff fluid.

The only chain your Service guy is yanking, is the one attached to your wallet. $400...

 

15k miles sounds right for the first change.

But for the love of god, do not spend $400 to have them change it. You can do both diffs in less then an hour your self.

I went with 75-90w Amsoil fluid but you can use whatever brand you like.

-Remove the bolts(I go from the bottom bolts to the top, you can leave the top two bolts on and pull the cover towards you to eliminate a massive amount of fluid splashing everywhere)
-Catch the oil fluid
-Check out the inside to make sure everything is in order(no excessive metal shavings, ect)
-Refill it
-Put that $300 and some odd change you saved by doing it your self and go spend it elsewere.

My 03 takes 3.8qts in the rear & a little over 2qts for the front. I beleive the 06 has a 11.5" rearend so you may need a little more. Consult your manual to make sure or someone else will chime in with a diffinate answer.

 

You can do it yourself for about $80.00 in fluid and a hours worth of your time.

 

The manual shows two different change intervals one for sever service where they say to change it at 15,000 and for normal usage you change it out at 120,000 miles. My self I changed the factor junk out at 10K with Amsoil 75/90 SVG and feel it should be able to go no less then 30K between changes. IIRC Amsoil claims their gear oil can go 50K before it needs to be changed out and that’s for sever service. BTW, it took about 7.5 qt’s to change both axles in my 06.

 

The Valvoline 75-90 syn. I filled mine with has 48K on it right now and still looks new. While I was under warranty I checked the fluid every 15K and just cleaned the metal off of the magnets on the fill plugs. There's no way the dealer could have proved it was in there for more than 15K, though I'm sure they would have claimed it was. The 15K interval is hold-over from the days before syn. gear oil.

Nick

 

I changed mine before the 1st 15K, sent in an oil analysis to see how the Mopar fluid held up, I would recommend you get it changed as the UOA said the visconsity was low/shot. I also installed the Mag Hytek covers at the time I changed my fluids. I put in Amsoil Severe Gear 75w140, I tow heavy and quite frequently. I did an oil analysis after 10K on the Amsoil, the MagHytek covers make getting fluid for the UOA really easy. Long story short, the UOA said that I could easily go another 10K or more, that my diffs fluids were still like new.

CD

 

Look at it this way: While you have only 15,000 miles on your truck (and if the diff fluid has never been changed), it might be worthwhile to change the front and rear diff fluid. This will allow you the check the gears for abnormal wear and to also remove the metal shavings.

Then, replaced the fluids with extended drain synthetic fluids and do not worry about them for along time.

 

I changed my rear diff fluid an hour after I bought my truck!!! You should have seen the Grey, Milky, nasty "Water" that came from that truck and it had 65 miles on it!!! AMSOIL 75 90 for the first 15,000 and then I went to Amsoil 75/140. I am going to change every 15,000 until my warranty is up just for proof.

 

Just checked my receipts. My dealer did an oil/filter, fuel filter, rear diff, and auto trans service for $363 total. I do mine every 15K as most miles are towing.

 

Lots of good stuff.
Thanks everyone.

 

My 03 manual says 15K for severe (B) and "never" for normal (A). Seems there should be some in between space. I don't tow much and change about 30K miles. 75-140 syn that got rid of the noise I had with 75/90. It comes out looking like it just went in.

Cya

 

Buy your gear oil by the 5 gallon pail and save a bunch of money. Make sure it is a GL5 (IIRC) rated Synthetic and you will be in business. I bought a hand pump, some extra plastic tubing and I just pump until it reaches the correct level. The Owner's Manual specifies synthetic for our trucks.

 

I put Mag Hy-Tec differentials on and changed to 75W140 synthetic. Going to sample and check the magnets at 30K, if everything looks ok, its staying in there.

 

I just changed mine at 15K...glad I did, cause the rear diff fluid looked horrible and plenty of metal shavings on the magnet too. Front wasnt too bad.