Hi everyone, I was rather shocked when the dealer where I bought my 3500 automatic Ram 2005 told me I should be having something done to my differentials (I didn't quite get what) every 12-15,000 miles. The cost was over $100. I looked through the Schedule B maintenance manual and I can't find a thing about when one is supposed to have something done to the differrentials. I have a friend with a 2003 and he told me he only does whatever this is every 30,000 miles. I AM towing--that is mainly what I am doing with the Ram 3500. I also love the mountains so it can get some mountainous terrain. Could some of you with experience please tell me if the dealer is just trying to get more work by telling me I have to have the differrentials serviced so frequently?

Thanks, Eileen

 

I took my truck in for some warranty work on the transmission about a month ago and while it was at the dealer, they wanted to do the same thing to my 02. They said they wanted to service both diffs and the transfer case for $100 each. They told me it should be done every 15,000 or something like that, which i think is overkill. I can see every 30,000 if you tow heavy and often. But in my case i don't tow that heavy or that often so i'll go longer, i usually check the fluid once a month too. Plus i can do it myself for cheaper than $100 per axle. Thats just my $0.02
Matt

 

Probably trying to get you to buy a fluid change for your axles.

 

That a gas...

The service manual states the fluids should be changed every 15,000. If synthetics are used, you should be able to go longer than that.

I go 250,000 in the Mack using the same fluid and working it a lot harder than any Dodge will work. At least they don't tell you to use a "special" Mopar 75/90 fluid.

 

The diffs aren't that much different from '95 to '04.
My manual says they are lubed for life (don't believe that) or change every 30k if towing.

I changed the rear diff fluid on a '97 a few weeks ago that had never been changed, original owner who towed with it, 180k miles.
I know it's impossible to evaluate an oil's condition by just looking at it but his oil looked brand new.

I use Royal Purple synthetic in my rigs and change every 30k.

 

Id have to say 90% of the cars on the road have never had the diff oil changed and never will. Oil dosent wear out, it just picks up contaminates like metal particles that wear things out. IMO 15K is overkill. $100 each hole is a bit pricy considering dino gear oil is $3 a quart and each diff holds 4 or so.

 

Here's an extreme example.
I have a an '82 Toyota PU with 312k on it, bought brand new for $5800. It has the same differential, tranny, brake and power steering fluids in it that it came with new.
Would have the same coolant except that I had to replace the water pump at about 200k. I did manage to change the engine oil every 10k though. Never thought I would keep it so long, driver's side door hinges have worn out twice.
Still drive it a few times a week for short trips where the Cummins wouldn't get warmed up, still rides the same as when new.

 

I did both of them at 15K, just like the manual says.
Had them done at the Dodge Dealer, and paid nicely for it.

I figured it was good insurance, should something happen, warranty would never be questioned.

That being said, I now have 51K, and haven't touched the diffs since that day.

I don't remember ever doing them in any previous vehicle I owned.


phox

 

If you tow a lot it is a very good idea to change it more often with synthetic(I do mine about every 40-50K). Average daily driver doesn't need it done near as often, unless it has a limited slip, which may need additive added infrequently, and the oil changed.

I have also seen lots of older vehicles(cars mostly) with 200,000+kms with still all original oil in diffs, tranny, brake, p.s, with no ill effects. I don't like to take too many chances with my rigs though, I'm not that lucky .

 

I changed mine at around 35K, the rear was way dirtier looking than the front. The front looked brand new and the rear was dark and dirty looking.
If my dealer will do it for $100 I might take him up on it.
They don't use a gasket on the covers, just silicone, which is a royal PITA
to get off housing and cover for re-assembly. Next time I do it myself I am going to install one of those expensive rear covers that use a big O-ring
instead of gasket or silicone.

 

I change mine every year, which is about every 35k. I switched to the Mag Hytec front and rear diff covers to make the changes easier though. Of course I use synthetic as well.
mishkaya

 

Another thought on it all, if your using your truck to launch boats and submerging the rear end then its a good idea to check or change if contaminated.

 

Eileen,

Most of the posts on here in response to your question has been by the 2nd Generation Dodge Truck owners. Your truck, like mine, is a 3rd gen Dodge and has AAM Axles. It is a different company and different differential than the Dana Axles that their trucks have. If you are towing regularly and heavy, Dodge says in the owners manual that you should change out the Fluids in your axles at 15,000 miles. If you are not towing or towing light, every 30,000 miles is fine.

You can use any GL-5 Gear oil in the Axle. I change mine out every 15K and use Mobil 1 75W90 gear oil. You do not need any additives or anything else put in it. Just the GL-5 Gear oil of your choice. I think some of the Dana Axles require additives, but your axle is an AAM....Not Dana.

All you do is loosen each bolt on the pan cover, allow the old gear oil to drain. Take off the pan cover and (if you want) spray the gear housing out with Brake Cleaner. Let it dry for a couple of minutes. Place the reusable rubber gasket back in place on the pan, place the pan back on the housing and tighten the bolts, but not to tight. Then refill the differential through the check plug on your pan cover. It should be within 1/4'' of the top of the check plug hole to almost coming out of the hole. It is easy to do.

If this still intimidates you to do this, then take it to the mechanic of your choice. Probably will be cheaper than the dealer.

FYI, that first change at 15,000 is probably the most important because your gears have been "breaking in" and have left some of their metallic particles on the magnatized fill plug. After that first one, it may not be as important to do it that often. To me, it is just cheap insurance to go ahead and do it every 15k.

Remember your truck is a 3rd Generation Dodge....so a question like this would probably be better answered in a 3rd gen Drivetrain forum area. No offense meant to any 2nd gen owners.

 

Thanks so much, everyone. I found out today that AXLE=DIFFERENTIAL. So I was looking in my maintenance manual for something about differentials and finding nothing because they are called axles in the manual. I do now see what everyone is talking about. In other words, it DOES say to change the fluid at 15,000. I will be careful to do this because of the metal particles (I'm afraid I will have to have it done out of town, because I won't be home when I hit 15,000). I also called the dealer again and the man with whom I spoke said just what some of you said: it's important to change the fluid at 15,000. But after that he said he would change the rear ones every 15,000 but let the front ones go 20-25,000 (because I don't use 4 x 4 that often). I appreciate all of your help. I feel like I'm finally getting some clarity on what I am supposed to do when. This is my first diesel. . .

Thanks again, Eileen

 

Eileen,

I wouldn't overly concern yourself about doing the gear oil change RIGHT ON 15,000. Your axle is not going to fall off your truck if it went to 16 or 17,000.

I would do it at a time that is convenient for you as close to that interval as practical. If you have lets say 12,000 on the truck now.....then go ahead and do it before you leave on the trip.

Whenever you do decide to change the gear oil.....I would do both front and rear at the same time. I wouldn't do the front on a different schedule.

Personally, I go ahead and change out the Transmission fluid and transmission filter, transfer case fluid, and both diffs every 15K. I change engine oil and oil filter every 5k with 3 gallons of Shell Rotella T 15W 40 and fleetguard Stratapore filter. And, I change the fuel filter every 10K with a new Fleetguard filter also.

Your truck should go a 1/2 million miles or more, if you service it regularly. Good luck.