Thread: GREASED OR OILED WHEEL BEARINGS

Oil is always a better lubricant than grease, in all circumstances - it flows back between moving parts, where grease can be permanently displaced, leaving an interface between surfaces unprotected.

Grease should only used where oil cannot be kept in place - and the problem with wheel bearings is that if you use grease, you do not know whether the seals are working properly (with oil you know if they are leaking!).

The Landrover setup (Series/Defender etc) was originally designed to use oil, and wheel bearings were only changed to grease when preventing oil leaks became a higher priority than providing good lubrication.

Wheel bearing failures only became a common problem after the change to greased bearings, some time in the nineties, from memory. (Series 2a changed to specify initial lubrication with grease rather than oil, deleting the filler plug on the drive flange, but they still remained oil lubricated as there was no seal between the swivel or axle oil and the wheel bearings).

In my case, I have never replaced wheel bearings on either my 2a (I have owned it for nearly twenty years) or my 110, which has now done over 500,000km, of which I have done over 400,000. Both are, of course, oil lubricated, as they were from new.

The problem with oil lubrication is that it depends on good seals and sealing surfaces - and this means fairly frequent seal replacement - but at least you know when they are leaking; with grease the seals can let let water in and you don't know until the bearings fail. A further problem with grease lubrication is that it means there is a good chance of the spline between the drive flange and axle running dry, and wearing rapidly, sometimes to the extent of failure, something that is almost unheard of with oil lubricated bearings.

John

It was the wear on the axle splines that first raised the suggestion I convert my defender to oil lubrication.

Originally Posted by stage one

My wheel bearings are greased and lots of it, in my 1980 s3.



. The original design works well, if it's not broken, don't fix it!

The original design would have been oil lubed...

To the best of my knowledge the oil lubed rear wheel bearings in my Stage 1 are the originals coming up to their 31st year.
Not bad for an unreliable Land Rover lol

Originally Posted by djam1

To the best of my knowledge the oil lubed rear wheel bearings in my Stage 1 are the originals coming up to their 31st year.
Not bad for an unreliable Land Rover lol

To the best of my knowledge all the oil lubed wheel bearings on my 2a are original - coming up to their forty-first year.

John

I found some bearing wear in my rangerover (oil lubed) somewhere over the 300,000km mark. Taking into account the old dealer being dragged through the courts for winding back odometers I think that's closer to 500,000km. The new bearings meant I could actually push the vehicle on level concrete.

Fast forward a few years and I fit some axles from a 97 discovery with greased bearings, with less than 100,000km on them. Front wheel bearings already showed signs of being redone, blue patches on the lock washer suggest it got quite hot.

Needless to say, I converted those to oil too.

I know many here use the double sprung seals for oil lubed hubs. Just thought I'd relay an interesting conversation I had a couple of years ago with my local bearing/seal supplier about double lipped seals which may give another perspective.

He explained that the double spring type is really designed for situations where oil is on both sides of the seal eg internally between a gearbox/transfer case which both contain oil but where mixing is undesireable.

Reason being is that the sprung lip needs some oil to lubricate the seal running surface when held against the collar under spring tension. When the outer sprung lip is not in contact with oil, it will quickly wear the shaft. Also the outer sprung lip may be less effective at keeping sand and grit out than a dedicated unsprung wiper lip. Any grit reaching the inner sprung lip will quickly destroy it.

He recommends using a single spring seal with an unsprung dust/mud outer wiper lip. This is still a double lipped seal but only one lip (the internal one) is sprung) It may seem like the sprung outer lip helps to keep oil in but it really does nothing in this regard and may increase collar wear and lead to early failure of the inner lip due to grit entry via the outer lip which is only designed to seal against oil.

My own experience at least shows that the single spring type works - I've been using the double lip single spring type on my (oil lubed) hub seals for several years without any leaks. (The seal Land Rover use for greased hubs does not have any springs at all and is really just a dust/mud seal)

All seals pass enough oil to keep both lips lubed. They're also usually installed with some grease on the surface to provide initial lubrication.

Your local seal suppliers comments make perfect sense for hydraulic applications, but for this particular application you're not going to find an outer seal lip of the type you've described, mainly because the seals are made from one material that has to do both jobs.
The outer spring is to keep the outer lip planted and prevent anything getting under it.

If you had the space to fit both internal and external seals, then everything would be fine and dandy. The outer seal is made of a completely different material and doesn't need spring tension. Just like a hydraulic cylinder. But we don't have that luxury here.