Hello everyone,
I have a 2004 Dodge Ram 5.7 with a 3.92 rear end and the limited slip differential. Around 15k miles ago I did a diff fluid change and found one of the dreaded C -Clips on the magnet. I drove the truck for another 12k miles or so waiting to see if it got worse. Well it did. The rear end progressively started making a whirling noise that kept getting louder and louder. I ended up having to replace practically everything but the housing and axle shafts. The rear end is now very quiet and seems to be functioning properly.

After the repair was complete I asked the differential shop how often I should change the rear end oil. I had been changing it ever 15k miles. The truck had 150k on it when the repair was made. Their comment was they suggested to never change the fluid from here on out. I found that strange, but thought I would ask for opinions here.

Sam

 

You'd be surprised how many people never change it.

SJ03

 

unfortunately you have experienced the dreaded "C-CLIP" problem I went through last year. My 04 came with the 9.25 chrysler LSD and I was doing regular maintenance and noticed some metal pieces that looked like staples on the magnet. I had felt the rear diff acting funny and put some of the mopar additive and it helped until I pulled the diff cover.
I ended up having the locker changed out to a detroit true trac so I do not have to go through this again. Best driveline shop in vegas charged me 1500 for a complete rebuild and so far so good.
Changed the fluid at 2k, and 5k, now it is looking like honey every time I pull the dipstick on the mag hytec cover I put on.
I think whoever told you not to change the fluid just does not want you to see what it looks like. I just about flipped out when I first looked at how much metal was in my brand new rearend but after 2 changes she is running pure and clean.

 

Ok, so, I have a 2004 quad cab 4wd hemi. This rear end issue is making me paranoid. I've noticed some "oil spots" on the rear end which heightens my worries. I'll add some photos tomorrow.

Can you all break this down for me. Where is this magnet located? How often do you recommend fluid changes? What am I waiting for to detect an incoming fail, just the noise? Can I do anything to help prevent catastrophic failure before it happens?

you all are gonna wonder, but this truck just broke 40k miles. Yes, just 40,000 on a 2004 lol.

Thanks for the consideration!

Mark

 

How long has your truck sat not moving/not running? Your "oil spots" are probably because gaskets, seals, and hoses dried out from not having fluids moving around them to keep them soft. I'd inspect everything made out of rubber and make sure that you aren't going to blow a hose or belt soon. Low miles isn't always a good thing.

As for the differential, it is at the bottom of the housing when you take the cover off of it.

 

I should clarify, the differential cover has "oil stains" on the back of it. there are zero drips. It is daily driver (I live literally a couple blocks from the office).

Thanks again!

Mark

 

On "back", do you mean by the driveshaft? Is your truck in the pool for the rear pinion seal recall? I'm not sure of exact years, honestly. My 2005 was.

 

Anytime the rubber plug is pulled to check the fluid level, it'll drip some. Spray some brake cleaner on it and watch for new stains to appear. If it appears around the plug, it could be over filled or need a new plug.

SJ03

 

Adding a picture. I believe 2004s were NOT included. . .

 

Time to take the diff cover off and check for anything on the magnet and reseal it with Mopar rtv and refill with Mopar or better 75w-90(????)and 4oz mopar additive. May want to look at the front too (75w-140)
I have never personally seen one just start to leak like that but the seal is 12-13 years old!
Did someone jack the rear end up with a floor jack recently? I always keep a piece of wood on my jack especially since I put the mag hytec diff cover on!
I would not stress about that unless you find the fluid is coming from the front where the drive shaft comes into it. If is has been sitting for a long time it may be the reason. Often times much worse on a vehicle to sit than to be driven due to seals drying up from lack of lube!



OEM off-road 17's, BFG-LT's, Airraid CAI, Cortex 3950, Magnaflow y-pipe, Detroit True Trac rear locker, Mag hytec trans & rear diff, SRT A-pillar w/autometer trans temp, 190 t-stat, cross-drilled/slotted front/rear.