There are "normal" drivetrain noises though too, right? ....and the extra combustion happening when you put your foot in the throttle, exhaust too, etc.....the diff to me, when I had this issue, was a little higher pitch....like a "whirring" almost a roaring....and as I said it was higher pitched than typical combustion/exhaust/drivetrain sounds. Not a screech like the EPB or the alternator....not sure what the T-Case noises sound like.

 

I understand this is a subjective assessment... However, I do think it is a bit more than one would consider "normal". Something in there definitely sounds tired, ...than again this is a 13 year old truck and I am a third owner... Who knows what the poor thing has been through :-)

I'll keep listening, might have to bite the bullet and take it to the Indy Rover guys we have here and have them listen with the ears Abran mentioned... Thanks for the input, really helps to bounce ideas off other people who drive the same truck. At the very least we narrowed it down somewhat...

 

Definitely let us know what you find ... I'm having a very similar condition (more pronounced at highway speeds under power) and would be interested in learning what caused your noise... Thanks!

 

Well, it's been almost a year since I posted about this. For those who are curious I finally rolled the dice on this problem and got dirty.

The noise was not getting any worse, but the deal breaker was when we took the LR3 to the mountains here in Denver, on the way up I-70 where it gets steep and fast the truck started vibrating in the front, like unbalanced driveshaft vibrating.... So much so, that I had to turn around and go get my girlfriend's LR4 to get where we were going. Was not a pleasant experience, especially considering that I had given the thing a pretty good tune up in anticipation of this trip. Injector cleaning, new plugs, new hubs, new belts etc. It never did this to me on the flat terrain...

I gambled on a used front diff. With Christmas and other things money was tight, so I just could't justify a new, or even rebuilt unit. I sourced one off a 2009 LR with low miles, cost me $260 including shipping.

Let's just say it is a bear of a job... I did it in my garage on jacks. The entire front end has to come apart pretty much before you can get the diff out. I ended up replacing the front driveshaft as well, since the old one came apart on me at the end mating to the diff. My guess it was on its way out because of the excessive vibration from the pinion bearing it had been attached to. I stripped one of the reverse torx bolts at the transfer case so had to get creative with cutting it and ended up replacing those six bolts as well.

I had replaced the clutch on my son's Focus a year back and his transmission weighed about the same as the LR3's front differential... It's a beast to maneuver back up. Now that I know how to do it, I can do it fast, but a lot of trial and error with angles.
It took me about 12-15 hours to get this job done from start to finish, not counting the time it took the parts to arrive.

Gamble panned out, noise and vibration are gone. I took her up the highway mountain the very route she failed on me and the SOB flew up there! No unpleasant experiences were had!

To those considering doing this, I would't even attempt to do the job without air tools. A good impact, air hammer are a must and make the job that much more doable. Patience and remembering that you do in fact love driving this truck also help...

 

Yep, I paid Abran to replace mine last year. Never regretted that expenditure!
Thanks for updating the post and hope this one lasts a long time!

 

Have any tips for someone looking to do this? I have a used front diff sitting in the garage that I am planning on cleaning up a bit and doing the actual install in the spring when it is a bit warmer.

 

If I can think of one thing that is a definite time saver is don't assume that if you were able to take the diff out with the passenger side half shaft tube attached, it will go back in with it attached. Yes, I know, logically it should.... I thought so too... I wasted a couple of hours fighting with the damn thing trying to align it just right... Many words were said, none of them were PG-13. Do yourself a favor and take the tube off if your replacement has one attached. Four bolts and you'll have to put RTV on it when you put it back onto the diff. When you are dropping the diff I would take down the entire assembly - diff and tube as one unit and when it's on the floor you can zip the bolts out with ease. Old RTV sticks pretty well to it and I had to give mine a couple of good whacks with a rubber mallet to get it to separate from the differential. It is much easier to do when the diff is out of the truck. Without the tube, getting the new/used differential bolted back up is a lot easier, as there is plenty of room there without the tube sticking out. You'll be able to attach it later when the diff if bolted up.

Otherwise, assuming nothing fights you it is pretty straight forward. I wouldn't call this job easy by any means, but it is doable. If you know your Rover and you have done front end work on it a lot of it is familiar. I had wheels off, calipers off, upper control arms, stabilizer links undone, tie rods separated and the axles pulled out of the diff in about two hours. Though, I have to say my LR3 never left dry Colorado, so bolts generally come out.... When I did the lower control arms (rear bushings, unrelated to this job) the bolts just came out. Given the horror stories, I had read I was prepared to fight, but, surprise! Also pay attention to the Torx bolts LR used to attach the driveshaft to the diff flange. They take E10 socket. They are also very easy to strip given the angles of access. make sure your bit is firmly seated on the bolt's head.

 

Did you check/test anything on the used diff before doing the install? Just curious if there is anything I should check prior to install. Also, did you clean or paint the used diff before install? The diff I bought has some surface rust so I was considering taking a wire wheel to it and possibly painting it.

 

Yes. Make sure the flange bolt holes on the used differential have their threads in good order. I forgot to do that and had to tap one of the holes with the diff already installed. A lot of fun that was! I replaced both seals for driver and passenger side half shafts. Lucky has them for $12. My biggest test was to spin the new/used diff internals by hand, everything should move freely, without any binding or funny noises. In my case there was quite a difference in the way things moved old vs new. Just remember, you are rolling the dice on this job, used diff is a used diff. There is a chance it might be compromised, or might fail within a 1000 miles of you putting it in. If at all possible, get a warrantied one, or a rebuilt one with a warranty. You can get a brand new one, but as our trucks age the new one is rapidly approaching half of the value of the whole car..... I got lucky (so far) so it might work for you as well.

I didn't paint the replacement. Don't see the point, it's tucked away above the skid plate. I am more interested in its function not its looks.
Good luck on this when you get to it. It is a challenging job, but very rewarding IMHO. Especially if money is tight :-)

 

Finally getting around to doing this job and I had another question come up as I was going through the shop manual. In the manual it looks like they say to replace the Torx bolts that attach the drive shaft to the diff flange. Does anyone know the part number for these bolts? I cannot find it referenced in the shop manual. Also, does anyone know if there are any other one time use bolts that I should order for this job?