[Mt.Hoodlum]

99 Durango, 5.2l, 4wd, with about 90k on it with the "9.25 LD Rear Axle". We had a grinding/grumbling noise a while back that went away so I never took care of it. It sounded like it was coming from the rear end and would only happen occasionaly when we were turning corners at low speeds. I changed the rear diff fluid shortly after that, did not find any chunks of metal. No more noise till recently.

So i had to take the truck into the shop the other day to finish my front end work, i did the upper/lower bjs an inner/outer tie rods on the left side but had the shop look it over and to the right side (long story). We drive maybe 10 miles or so running a few errands right after picking the dango up from the shop and the grinding/moaning/grumbling noise came back. It is like a woo/woo/woo noise not a constant noise. This time though, it only happened at low speed below 30mph while the truck is accelerating or coasting, when the brake is applied the noise immediatley stops.

I called the shop back even though they were closed and took it back over thinking something was wrong with the front end work they just did. He checked all his work over and we took it for a test drive. I did not say anything about the previous rear end noise I had heard to him. During the drive he said it sounded like it was coming from the rear to him. Back at the shop he pulled the rear wheels and drums off and looked everything over but could find nothing wrong. While spinng the axle by hand with the wheels off he said there was a cliking noise or something like that that was not normal. He called his rear end guy but was not available and just got back to me today.

He told me from what he described to his rear end guy (dammit i can never remember details....) that basically from the symptoms it sounded to him like something in the rear end was bent and could only happen from the rear end being hit or in a wreck. He asked me if it had ever been wrecked. I bought it used about a year ago and the rear passenger door has damage like it was in a wreck. Also the rear diff had a slow leak (from the bottom like the gasket hadnt sealed correctly) that I found after i bought it which has since stopped since i changed the oil. He said the camber and toe i believe needed to be checked, in the rear end i beileve to determine if this was the case. Dont quote me on this i dont remember exactly what he said. If that was the case he said, it may partially need to be rebuilt and quoted me $250-$350 for labor and $250-$350 for parts. So like $500-$700 total. He said it would last a long time like this but just get more expensive if more parts were damaged.

Anyone have insight on this? I know nothing about rear differentials and pretty much just learn as I go on things. How hard would it be for me to swap out an axle if I picked up a used one myself, or possible rebuild this myself? Special tools needed, what would rear end parts cost? He told me it would be around $300 for them to swap the axle if i got a used one because the brakes and all that would have to be swapped (rear drums which i have never done). I am quick learner and we do have a spare rig to drive for a while if needed. This weekend is the first time I have ever taken any of our cars to a shop, becuase of my ball joint fiasco and after i paid the $350 bill i now know why i do all of the work on our cars.

How do the $$$ quotes sound they gave me? I have found this shop to be pretty much the cheapest anywhere in town and they are extremly helpful with free advice and diagnosis. They let me stand in the shop and come down and check everything out underneath while they explain whats going on, and have done multiple free diagnosis for me and my dad when they knew we were going to do the work ourselves. This weekend was the first time they actually did any work for me other than an allignment.

I know this is long, just wanted all the info there. Thanks for any help.

 

[Mt.Hoodlum]

I think I will pull the cover off the rear diff this saturday and have a look at things if I have time after i put my new valve body in, probably be a good place to start.....

 

[Mt.Hoodlum]

well the rear def shouldn't be making any noise like that. if it needs to be rebuilt it's not something you can do because it's very precise and a lot of shops also mess it up. setting the backlash and adjusting the pinion depth is critical and easy to screw up it seems. i have been the victim myself on this. if this shop really knows what they are doing and you trust them then go for it because that is a good price. ask them how many rear ends they have rebuilt though, or how many each year because if they are not experienced in that then you don't want them doing it. anyone with a wrench can swap out the axle, but rebuilding the diff is a different story.

i'd probably pop the cover and take another look while someone rotates the wheels so you can see what's clicking. that would give you a better idea and us. maybe you could take a video or pics of it.

is it an open or LSD? it will tell you on the sticker in the glovebox if you don't know.

if you can find a good used axle then that wouldn't be a bad idea either. if you can find one off an 03/04 then you can take advantage of the rear disc brakes and loose the drums. you just have to be sure it's the same gearset as your front is since you have a 4wd. you most likely have a 3.55 ratio, which it will also tell you in the glovebox.

Thanks for the good advice. I like the sound of getting rid of the rear drums by swapping out with an axle from a later model with discs. There is an 03' someone is parting out here in town that I know of also. Would that simply be a unbolt and rebolt in job? Do you have to run new brake lines or mess with abs? Of course I would do alot of research and be sure my rear end needed to be replaced before tackling this. I will take seme picks this weekend when I get the cover off, will have it jacked up so I can spin the wheels to, didnt even think about that, thanks.

If you have the limited slip rear end, did you add in the friction modifier when you changed your fluid?? I'd pull it back apart. If there are small metal pieces in the bottom that look like half circles, then it's really nothing you did and is a common problem with the factory limited slip clutch pack. You can either have it rebuilt by a shop, or go with a locker. If you go locker, you can buy a Powertrax unit and install it yourself in your driveway since the carrier does not have to come out of the truck.

I do not believe I have limited slip.....There was no info in my glove box, and i went through this when changing the oil in the rear end when i did my tune right after i bought the truck. I ended up emailing dodge with my vin and getting the build sheet from them, and alls it said for rear end was this "Corporate 9.25 LD Rear Axle". So i did not add the friction modifier when I changed it. I wonder if it by chance could be LSD and I am having problems from not having the friction modifier in there? I found some threads on those half circles during my search on here last night, so I am not expecting to see any.

Thanks for all the good advice guys, will update this weekend after I get a look at it.