Hey guys,

I'm looking into changing the rear diff fluid this weekend. The only issue that I am running into is, i bought the truck used and there is no manual with it, so I am unsure of what type of diff that I have. I have an 04 Ram 1500 Hemi 4x4. I also looked for a sticker in the glove box, but there isn't one there. One thing that I do know, is during winter when it is really icy, only the right rear tire seems to spin. Which is a pain in the butt to get moving, especially on a hill and I have to put it in 4x4. Can anybody help me out? I have the fluid and RTV, so I am just wondering if I need additive or not, and to see if there is anything that I can do to the rear end to help me out during winter months. I do have aggressive winter tires, so that shouldn't be the issue especially when the left tire isn't helping...lol

 

If only one spins no matter how much gas you give it on slick pavement you have an open or a bad lsd. If the LSD is bad you won't need additive ne way cuz it's f**ked.

 

Sounds like you have the good ol "one tire fire" my friend. Only fix for that is an expensive one, get a good LSD like Detroit tru-trac, etc... As for the fluid, Id use the search function, as Ive read on here before, but my memory aint for ****, haha. Maybe others will chime in, but search around and see if you can find something in the meantime

 

if you're unsure, add the additive anyway... it wont hurt an open diff. or if you havent already bought fluid, just get royal purple, it already has the additive.
when you open it up you should be able to see the LSD in there...
i thought i had some pics of mine but i cant find 'em

 

Cool thanks guys.

 

The additive is actually bad for the seals as it dries them out quicker, but that issue is not something you should be worried about as it's used in lots of diffs and is such a minor problem.
Most Synthetic diff fluids have the additive in them such as Mobil LT 75w-140 so purchasing more is not needed. That is the weight reccomended also as i haven't seen that mentioned.

As far as seeing the LSD, not gonna happen. Unless you really know what you are looking for it will appear as an open diff. i would take it that you have an open diff. So, if you do not add additive(I wouldn't) and you get chatter, then that means you need to add additive and do have LSD.

 

If it's a clutch type differential, the clutch packs are going to be obscured by the ring gear, so like 'dog says, if you really don't know what you are looking for, it's not easy to tell if you have a LSD even though you popped the pumpkin...

 

Is there not a mini build sheet sticker on the inside of the glove box that indicates diff type and gear ratio? I think thats where I found mine but not sure, I removed it and plasticoted it.

 

Not sure if I agree with some of the comments here. I changed the fluid in mine last weekend. My truck has an LSD and I was able to see the clutch plate when I opened it up. Assuming you have the original 9.25 Corporate diff, there is a set behind each of the horizontal spider gears (the ones that are attached to the half axles). If you shine a light behind the gears, you should be able to see be able to see them. If there’s nothing between the gears and the carrier, then you have an open differential.
As far as having one tire spin on ice, it is possible for an LSD to allow one wheel to spin if one tire is on an extremely slick surface (like ice) and the other tire has good traction. There needs to be some level of resistance for torque to be transferred to the other wheel. If you look in the owner’s manual it tells you it’s possible for this to happen with the anti spin diff. If it happens all of the time, I’d agree that it’s likely you have an open diff. It’s never happened to me.
As for the job, it’s an easy one. Most of your time will be spent waiting for the RTV to dry before you add the fluid.

 

Can I upgrade the diff if it is an open?? I'd really like to take care of it, since I do haul my sled in the box sometimes, plus like I said it's a pain in the **** sometimes...lol