Non-locking rear diff with 147k miles.

I replaced diff fluid at 107k miles close to when I first bought it. I made notes then that the fluid in both front and rear were old and brown looking with no significant metal in the fluid. I filled with Royal Purple Max Gear 75W-90.

Changing fluid again today. The front had more buildup on the drain plug magnet than I would like to see, but no chunks of metal. The rear had buildup and chunks of metal.

40k miles, mostly highway driving, no serious off-road.

Any thoughts on the metal? Seems like a lot. Other than the seemingly normal LR3 diff wine, there are no other drivability symptoms.

I was going to refill again with Royal Purple, but now I’m 2nd guessing that call.

 

It is really hard to tell in the pics what size the metal flakes are. The stuff on the plug is a normal. No matter what there is always wear. I find the best way to inspect metal bits is never on a magnet, they align and makes things look worse. Get a coffee filter and wash then off of that to get a better idea of the size. But I don't think I would be too concerned at this point. And RP should be fine as long as it meets the spec of GL5, which I am sure it does. Now if there is an excess of wear then what? Generally as you know they will make more and more noise before some sorta big failure. So maybe just keep your eyes out for a spare and keep in driving. If there is an issue it could be thousands of miles before it presents. But again, wash the bit off the magnets for a better look.

 

Thanks for your feedback! I was thinking along the same lines.

We have a 2,300 mile drive to do in 5 days. It’s going to be out of my reach for about a year or more so just trying to head off as much as I can.

I’m filling with Valvoline Extended Protection 75W-90 just for good measure. I know RP is very reputable, but I lost a little luster for it after these 40k miles.

 

Okay, those bits of metal would worry me a bit.... I think your best bet is the new fluid and drain again when you get back to see if there is more metal.

 

I drove for about 25 miles, mostly highway speeds, 70-80 mph. I drained the rear diff warm and found one more chunk attached to the drain plug magnet and the lube had a bit of a gold sheen as I swirled it around. Refilled with fresh fluid and will keep an eye on it. My bigger problem is our 2,300 mile journey is one way. I won't be able to work on it again for a year plus.

 

What year? I know some of the early models had paint coating inside the rear diff which would chip off and cause problems. I don't know a whole lot about it just that it was a problem.

 

Front diff, not rear.

 

Sorry for the confusion to all. To clear this up...

2007 LR3 HSE, non-locking rear diff., 147k miles. The rear diff is where the metal chunks came from. These are definitely not paint chips. I ran a scope up into it and could not see any pieces of teeth missing, but I also could not fully inspect it.

Royal Purple gear oil was used at 107k miles in both the front and rear diffs. When drained at 147k, the front diff had more metallic dust on the magnetic drain plug than I would like to see. The rear diff had excessive metallic dust and the chunks in the pictures.

I've elected to send another car on the 2,300 mile journey ahead to buy more time to replace this rear diff. with a reman. I'll likely buy a rebuild kit for it rather than sending it back for a core. When I do, I'll autopsy it and see what really happened. If I have to guess, I think one of the carrier bearings is failing. There is a consistent rolling noise unlike gear mesh noise that would oscillate between coast and drive. I do have gear mesh noise in my 2006 with 186k miles.

 

No confusion, the front diff was painted and has issues. The issue being the paint flakes getting into the roller bearings.

 

Weren't those early diffs replaced under warranty anyway? I wouldn't imagine it being a problem now 20yrs later