Thread: Black oil in front diff

Hi guys, I have a little curiosity. Every time I check or change the oil in my Derfender 90 Td5 MY06's front differential see the oil always black (rear obviously no problem). The reason is clear: the grease that is present in the swivel passes in the differential's oil, or better, the differential's oil goes in the swiwels and mixes with the grease. The mechanic that checked and serviced the car first time (since that I always do it) said nothing to me and when I asked if it was normal he said yes. But I'm not convinced. Also happens to you? Is it normal? It should be fixed? I think to fix I should change the oil seal that is between the swiwels and the axes, right?

Thanks

Have never got around to converting my grease filled hubs to oil. Seems the reason for Land Rover changing to grease was they had the idea that it would stop the problem of oil leaking onto brake linings when seals eventually wore and hardened. However, it created other problems. The axle splines and those of the hubs are then likely to eventually run dry of lubricant and strip themselves. Ie grease squeezed out not inclined to work its way back in. I had one do this when vehicle had done only 35,000 km. So periodically fill the caps over the axles half full of gear oil with grease mixed in and slap them back on.


These plastic or rubber caps are prone to leak as they get old from getting hard or splitting. Seems genuine LR parts are best value. Looks like recently produced ones are improved. Rubber rather than plastic and look like have a bit more "airspace" to hold oil than older types.


I gather grease lubricated CV joints are more prone to failure than when housings are oil filled. Seems grease is inclined to go hard like cheese when it gets old and not necessarily spread into places where it is needed. Several years ago a local garage replaced dry looking chopped out CV's in another Defender. I have occasionally added some EP gear oil to my grease type swivel housings to hopefully stop this problem. ( Still have oil filler plugs on '97 build Defenders.) No apparent extra external leaks as a result. Presumably any leakage when hubs get hot would be into diff and /or wheel bearing.