Thread: Thoughts on breathers?

Diff failures are a known issue. Originally seals would fail due to contamination of diff oil by a coating used on the casings. There have been some instances of the diff breather one way valves (not filters) not opening.
Diffs are still failing but not leaking less failurs in later models though. I think it is more likely any new failures are down to poor manufacture on individual components.
It is better protected than most 4x4s but always good to change oil if you do a lot of wading.

Originally Posted by CaverD3

Diff failures are a known issue. Originally seals would fail due to contamination of diff oil by a coating used on the casings.

Correct, but there was a limited recall / technical bulletin based on that, it does / did not apply to all ever manufactured, rather a limited number. As it was stated before, the coating would mix with oil, creating a grinding paste.

I can understand that anything with bearings can wear out, I take issue with the fact, the manufacturer and LR would create a situation whereby the parts for reasonable repair are intentionally withheld to sell an entire unit.

We agree on the fact water contamination can happen, and attention should be paid to it. All I am suggesting, is that an ounce (or rather a pint or so) of prevention is worth a pound of cure (failure or noise). Having said that, the breathers are necessary, but evidently there is the possibility for some water contamination, perhaps it leaks in from the seals... who knows for sure..

Agree.

Maybe the one way valve is a problem? Hot diff cooled will draw air in so if valve is closed it could draw water fron a connection? If wading a lot I have seen some with filters repalcing the valve.

Attached is a pdf of the rear electronic differential showing the breather hose, part # TES500050.

I could not find any reference to that number anywhere so probably the number has been changed. That always bothers me as often that means the item rather than just having the price increased as per North America, the part could actually be changed and I presume improved.

What I was really trying to find is a picture of how the hose terminated at the top. I gather per CaverD3, the top end is some sort of one way valve but perhaps now it is a filter, or not!

What I am used to on American pickups is an open ended hose hanging back down from above and works OK until bugs start living inside the hose.

I also included the front diff as well, breather hose part # TAP500081

Originally Posted by unseenone

After reading through the thread, I get the impression nobody is worried about water contamination, and are assured based on these breather tubes. Think Again!!! The K is stated in Miles, rather than Kilometers.

[snip]

Condensation accumulating in the fluids is common, generally caused by short trips, the unit gets warm enough to pull moisture in through the breather on a cooldown, but the trip lengths aren't hot enough to vaporise off any said moisture.

The fix, as you've discovered, is more frequent oil changes, regardless of the quality of the diff oil used.

The diff only takes, what 1.1 litres ?

75,000miles is a snap in a semi, most can go 3-400,000km with full syn fluids but the diff capacities are upwards of 20 litres and they are hot all the time.

75,000miles/120,000km on 1.1 litres ? Hmmm. Doesn't leave much in reserve for contamination, either metallic, dust or water does it ?

Curious, what service interval is in the Oz service book ?

Originally Posted by rick130

75,000miles/120,000km on 1.1 litres ? Hmmm. Doesn't leave much in reserve for contamination, either metallic, dust or water does it ?

Curious, what service interval is in the Oz service book ?

The attached for the D3, Rest of the World, (do not know if Down Under had been discovered as of 30/1/2009, the date on the pdf), but the attached Land Rover pdf calls for "renewing the locking differential oil at 120k and 240k". For the front and rear normal differentials, it says every 10 years.

It appears that k means kilometres, so that suggests 75,000 miles and 150,000 miles in the New World.

There is then the disclaimer to the effect that extremes of ........ means more often for most items. I think Australia qualifies for the disclaimer, hence best judgement and 150,000 km is on the far side, let alone 10 years.

I've dropped diff oil of of a Sals that had in excess of 3 litres in it (oversized diff cover) that had exceeded 40,000km and it looked putrid, and there wasn't any moisture contamination.
Oil used was Castrol SAF-XA, an Australian specific 85W-140 PAO/ester synthetic.

I've never done any used oil analysis on diff or g/box oil either, but at the small (relative) quantities we use in our 4WD's, changing is cheaper than testing to extend the service life.

SAF-XO 75W-90 is the recommended fluid in the D3 diffs, as it is in a number of Euro makes and interestingly BMW used to recommend it be changed every two years.

I'm guessing Land Rover has ran the vehicles in a temperate environment (the UK) pulled samples for testing at, say, 60,000km and in concert with Castrol, their fluid supplier, extrapolated those results for 120,000km.
Maybe they've run a fleet of them to those service intervals and the lubes tested OK ?

I've proven to myself through oil testing that premium oils can exceed manufacturer recommendations in the right circumstances in engines in good tune using good quality low sulphur fuels, but I'm not convinced of these extremely long life recommendations for other lube compartments with tiny fluid capacities and no filtration.
It smacks of reducing servicing costs for lease customers.

Originally Posted by SuperMono

Poking around under my recently aquired D3 today and had a look at the rear diff breather setup (runs up near the fuel filler by the look of it).
I didn't locate the Gearbox/TR breathers as I decided it was more important to attend to a few other minor issues.

So I decided to seek your thoughts as to if a D3 needs any additional attention to Diff, Gearbox & Transfer case breathers?

My D3 is not intended as a long distance tourer and generally I avoid deep water and mud anyway.

Thoughts, comments?

I think it might be a good investment. Looking at a twin breather kit water in any oil is not good. Was going to change Diff oils with my next service, might add it to the new compressor- doh. The Twin kit might allows a fairly neat fix to the this if it is an issue for those who use our D3s as a submarrine