Had both front and rear differential's serviced at the dealership and was told that Dodge now says this should be done every 20,000 miles. What do you guys think? Thanks, Varmint...

 

Any idea what Gear Lube they used?
Seems excessive...unless towing heavy or racing. Also depends on what fluid you use. High grade synthetic should be conservatively good for 50,000-60,000 miles IMO. National brand (non synthetic) should still be ok up to 30,000 miles.
But changing more often is cheap insurance and can't hurt. (Easy to say with a Mag Hy-Tec)!
RJ

 

If you check your owners manual, (schedule B) I think you'll find is says to change the fluid in the diff's every 12,000 miles.

 

You have got to be kidding? No way I'm I going to change my differential oil every 20,000 miles let alone every 12,000!!! What a waste of money. I changed my diff lube after 30,000 to get ride of the contaminated break in oil. I refilled with Valvoline 85-90 and two bottles of friction modifier. Given the lack of towing I do, there is no way I am going change it for at least another 50,000 miles. If it starts to loose its color by then then I'll change it again. I guarantee that my differential will be working fine for years to come. Now I dont treat my LS bad either. I dont do a lot of U turns and I also try to stay off the gas when turning since that loads the slipping clutches more which just makes them wear faster. I dont let ONE tire spin faster than the other and I dont run different size tires on the rear (smaller/bigger spare). I dont live where it gets below freezing so I dont use synthetics and I also dont tow heavy often so I use a lower weight oil.

 

Can't say for the earlier models but the 04s are supposed to be changed every 15,000 using synthetic. If you have LS then you are not supposed to add friction modifiers. These new LS differentials are different than the older models from what I understand and they don't use clutches. Additionally the 6 speed tranny isn't supposed to have the fluid changed unless it gets contaminated. I buy 75w-90 synthetic by the 5 gallon can and then it costs me less than $5 a quart. Only have a little over 6000 miles on the truck but starting to pick up the common maintenance items so they don't all hit a once, big $$$$$$.

 

Me personally would change every 30K.

As with Idaho dirt roads and a wee bit of 4 bying... I tend to see the fluid start to darken up about 25K.

The dealer did the first change and put in Syn 80W-90 and believe it or not it only lasted 7K it also cost me $120 for both axles to be changed!!!! It looked like old engine oil it was really burnt! (And yes I check it before and after service with d e a l e r s - I don't trust them much!)

I changed and replaced with standard dino gear lube 80W-90 and so far I'm pushing over 18K and it looks like honey yet in both the front and rear axles! (Checked every month)

 

04 2500 4x4, Schedule B states every 15k miles on rear end, even though factory fill is with synthetic.

I changed everything underneath to either Amsoil or Redline at approx 7k miles. I have almost 19k on truck now and no complaints.

Frt & Rear End to Amsoil 75-90W Series 2000 Synthetic
Transfer Case to Amsoil ATF
6spd to Redline MTL ( Amsoil doesn't make lube for this transmission and recommends engine oil???)

Gear Train is quieter too... Even though AMSOIL claims a lifetime fill on the Series 2000, to stay within warranty, I'll change at 25, 40k,etc.

 

I am terrible I just did mine after 70000

 

And the fluid level is supposed to be a half inch below the bottom of the hole, correct ?

 

I've got the popcorn...think I'll sit back and just watch this time around!
RJ

 

I started a fire, got the hot dogs and marshmellows ready! Who brought the drinks?

 

Should be level with the bottom of the fill hole.

 

Just get a Mag-Hytec cover with the view finder thing in it and watch the oil, if it's nasty black..change it! Simple!

 

According to the Owner's Manual, on the 3.73 rear end fluid level is suppose to be 1/4 +/- the fill hole. Apparently, Dodge sent a correction to one person on this forum stating it was suppose to be 1/2 below the fill hole. Still, others have a mark on their rear end covers. Personally, I think Dodge was underfilling them from the factory in 03 and early 04 and that's why so many problems with whines were developing. And, instead of issuing a recall to fill them correctly, they just decided to print a piece of paper saying the Owner's manuals are wrong...Just my .02 worth.

I keep mine, just seeping out of fill hole....No problems yet with any axle seal leakage as of 19k miles.

 

Ok, level it is then. Thought I remembered reading somewhere that it was to be below the fill hole, but that goes against any axle I've ever worked on
Thanks!