Hello, this is my first post here. I recently purchased a 06 2500 4x4 auto, nice truck but one thing that i have noticed is i a slight roar from the rear axle at about 30 mph and 68-75ish. The truck has 49,000 miles, I,m about to do a fluid change in the diffs and was wondering if a heavier fluid say a 75w-140 might help out with the noise or any other suggestions??

 

I would go with the heavy oil if you tow alot, otherwise you should be fine with the stock wight stuff. id also check for wear on the ring and pinon. any other mods to the truck? fill out your sig so we can see what ya got!

 

A roar from the rear diff is a sign of bad things to come in the future. Make sure it's not the tires from cupping or other driveline parts.

 

Also, spec on the oil is GL5 full synthetic.

While you are changing it, you might pull the rear cover, and see what the contact looks like.

 

Any unusual noises coming from the gears is a warning to get ready for new ones. Crawl under there and do a quick hand check touch for temperature after next time you park it. If the noise is definitely coming from the rear, it hasn't had fluid changed in 49k and it's getting hot, they are on the way out.

 

I just had mine in the dealership this past week as I was hitting the road again w/RV.
I thought it was my tranny making a growling noies at take off, but the Diesel tech was convinced that it was the rear end making the noise because it didn't have the additive put in when I did the lube change. I commented that the book says it's not required, but he said that's wrong.

Anyway, mine is getting louder and louder. Only when takeing off and the wheel is turned a bit.

Just gotta make it thru today and hope the POS Marathon tires on the TT hold up, and it's going back into a dealer....

I may first pull off the cover, drain and clean everything out with solvent and refill with fresh, heavyer lube and additive. You may want to try this?

 

I have done everything suggested, and still at 125k the bearings in the rear diff are toast. Getting a whine that comes and goes at certain speeds, a constant noise from the rear at road speeds, and the pinion is getting way hotter than I think it should when towing.

This after normal fluid changes, heavy fluid, and no metal to speak of in the drain. Seen this on a couple of gassers also and am convinced it is just the crappy material the gears and bearings are made of. I am almost positive I am going to find pitted and scarred bearings from a flake of metal off of something that has run thru the bearings.

Only thing I can figured is the composite metals they are using to cheapen production are not holding up to extended heavy use. They seem to be fine if you run empty or tow light but extended towing and weight is causing some flaking that is taking out bearings.

 

why didnt they stick with dana's?

 

From what I have seen, the AAM axles have been superior to the Danas. Have only seen one AAM needing overhaul, and it had quite a bit of water in it. They seem to be at least as strong as a Dana 80, and far better than a 70. The seals in their front axles seem to be better than what Dana uses as well. It's just too bad they do such a lousy job designing u-joints.

 

I only have 46k on the truck and have only towed heavy 7days of it's life....

 

The Jeep Liberty is why Dana and Chrysler departed. Chrysler had Dana build a alum. front end on the 4wds. Dana explained that it wouldn't hold up. Chrysler insisted that Dana build the unit, they did with no warranty. Chrysler got mad when Dana wouldn't fix them under warranty and thats what happened.

That was the story I was told.

 

Mine was making noise at 11000 miles and they thought is was a bearing in the trans. They changed it and sitll made noise. Turned out rearend crapped out. Thank goodness this happened under warranty.

 

AMsoil makes a good 75/110 GL5. Thats what I use. I tow on weekend and also a daily driver. Nice Inbetween. Correct, no additive required but it has helped LOTS of guys on here for who knows why.,

 

I it were me, the first thing I would do IS change the rear diff fluid to a GOOD quality fluid. I changed mine out to Amsoil 75w140 at 15K miles.

Long story short, I first changed mine at 5K miles, replaced it with the Mopar fluid. I had been experiencing the hop everyone talks of, thought maybe changing the fluid might help. It did, but for only a short period, then the hop was back again. I then changed it out at 15K and put the Amsoil fluid in. I sent an oil sample off on the fluid I took out at 15 K, it had 10K on it, and the report came back with lots of BAD, littlerally no visconsity to the Mopar fluid after 10K.

If your truck was maintained at the recommended intervals, chances are the visconsity died long before any fluid change took place per their schedule like I had experienced.

I live in a hot climate, tow regularly, tow heavy loads, the 75w140 is what was recommended to me by a REPUTABLE DODGE dealership that has tons of experience with our trucks. The heavier fluid did not affect my fuel mileage whatsoever. I have it in both the front axle and back axle. I recently sent in an oil sample, 20K miles on the Amsoil fluid, their recommendation was that my oil in both diffs STILL had plenty of life, not recommended to change fluids at this time.

CD

 

I did use Amoil.
The dealer that las looked at it said it DOES need additive even as Dodge says no.....

Took it to another dealer tonite and the service adviser was right on it as being rear end noise. She said that the clips holding everything in have a habit of breaking and letting the diff gears cant in the housing and that usually the houesing is ok.......

I think I may try to track down some Royal P im the AM, douche it all out with parts cleaner and try it again with heavier wt 75/140.

Backing up this PM sounded like there was a box of rocks in a crusher...could feel it throughout the truck. Put it gear and go straight, notheing.