I assume this is not normal when everything is new. 2006 at 230k miles. Guessing this would be a very worn output bearing? Diffs are not my thing. I have a vibration that has been getting worse over time. I had swapped CVs at one point and it seemed to improve but not for long so maybe it was just in my head. This is front driver side, so no long tube extension making a swap pretty easy. Unless there is a bearing in there that can be replaced with the diff in place I will likely just swap the whole diff for a lower mileage use one. And yes that is green moly CV grease, found this issue because I blew up a CV and had to swap again. That is how I found this issue.

 

Holy smokes. Yeah, I'd source a replacement diff.

 

Already did, should have it this week and hope to replace this weekend. I did look into it and as I kinda suspected the driver side bearing is large and only replaceable by taking it apart. Unlike the passenger side where there are two bearing with the far outer one being pretty easy to replace with the diff in place. Will swap and probably take apart my old one to see how worn it is and maybe rebuild it - they seem pretty easy to do.

 

Pointless update... but the place I bought my used front diff from gave me a rear instead. I was in such a hurry to get to them before they close AND get back home, I did not even notice.... until I got home. The diff I ordered was from a 2008 with 180k. But because of the mess-up I instead got a diff from a 2006 with 229k miles which I picked up yesterday. The only silver lining is that it is a reman with a 2010 date. Externally it looks like crispy fried chicken but the inside looks good. Bearings actually seem fine too. Seeing that it is a reman it should, in theory, not have the coating inside that was taking out the early diffs. So I think I will do a partial rebuild on this used unit and swap it in. I will take pics and such since there is not a ton of info out there. I will likely not rebuild the pinion portion unless the bearings seem bad but they seem super smooth and good. I almost hate to rebuild it but with a reman date of 2010 (not sure when actually installed) and 229k miles, I think I better just do it and be done. I will probably still rebuild my original one but I want to take it some place to get the body cleaned of that horrible internal factory coating.

 

So are you still on the hunt for a front diff?

 

No? As I said, I finally got a front after the mix up and a lot of driving. Press arrives this week so maybe this weekend I can get new output bearings/seals on it, clean it up and maybe install it.

 

Ah gotcha reading the post I thought you were working on the mistaken rear. Interested to see your updates on the minor rebuild.

 

Ah, yeah that went back when I got the front diff from the same place. Took it apart tonight for initial inspection. Looks good to me but made another post to get input form those that know more than me. Will replace the output bearings and seals. Will take pics. Honestly it looks pretty easy and straight forward.

 

Outer bearings are shimmed to get a proper clearance and I don't know what the endplay needs to be, can't find that info anywhere.
I am currently dealing with a replacement diff saga myself: the one in the car has heavily pitted gears (put a camera inside), bought replacement that my buddy volunteered to pick up, which he did without even looking at it, when I opened the drain it had liquid metal pouring out of it. Went back and got another one that was full of chocolate milk but no damage to the gears that I saw so I took it apart, cleaned it (hot tank) and noticed minor damage to the bearings. Brought it to my transmission guy and he told me to just assemble and run it as is, DO NOT change bearings as it will need to be shimmed for the new bearings... but I might still do it anyway because I already have it out, hoping someone knows more about shims

 

Wow, that is bad. Make sure none of the inside coating is coming off too. Ideally you want a donor diff from a 2008 or newer since the rubberized interior coating should not come off, but not from an LR4 since the gear ration is prob not the same. 3.73 is the gearing needed for the LR3. I actually just finished that extension housing tube today. New bearing and seal and ready for install onto the diff body. The diff itself is pretty easy to work on but I have one output/carrier bearing inner race that is not wanting to come off easy - the passenger side. The pinion bearings are the same, two needed. But the output bearings are not the same side to side.

As for shims.... well that is related to why my project is stuck right now. I decided to buy NTN/National bearings. Had to mix because of availability form Rock. Rock Auto does not sell Timken. Timken is what Dana used on these with a Koyo pilot bearing on the tube. And what I found is that the National I bought has a taller race than the the original Timken. Crap pic below. So now I have a Timken on order for he driver side and I may get Timken for the other side too. In theory they will be made to the exact same spec as before and therefore the same shims can be used. Lesson learned, maybe. I also have shims on order but they are for a Dana 35, not 30 so not sure if they will work.

The end result is that instead of just swapping bearings like I hoped, I will have to dry assembly the diff and actually rebuild it the correct way - paint it up and see how things mesh together, etc. At least if I want to feel good about this rebuild. With that said I still plan to rebuild my old one once out too.

Side note - not sure why, but almost every place I looked at has the left and right bearing swapped. They will list a bearing for the left but it is actually for the right and vice versa. I thought I had the wrong bearings sent. Once I saw I could flip em I started to wonder if I was breathing too much brake cleaner. But sure enough there must be something wrong in a catalog some place cause almost every has them reversed.