Diff oils

Morning
Just a quick question can I use EP80 W90 gear oil in my diffs on a 2003 TD5 Disco

As long as it meets spec API GL5 yes.

cheers

Better put 75W90 gear oil recommended by LR though, there's no extreme pressure in the diffs to use different spec EP stuff

sierrafery said:

Better put 75W90 gear oil recommended by LR though, there's no extreme pressure in the diffs to use different spec EP stuff

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theres a fair bit between the crown wheel and pinion teeth, and ep is quoted for other models using the same diff

sierrafery said:

Better put 75W90 gear oil recommended by LR though, there's no extreme pressure in the diffs to use different spec EP stuff

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Now don't be silly.

Same SAE oil is it not 90 for both.

I know EP90 was recommended for D1s and RRCs then from D2 LR started to recommend 75W90 for diffs and transfer case, maybe they've got smarter ... from all the advertisings i've seen EP was recommended for various gearboxes not for diffs... but i'm not gonna contradict the masters on this

sierrafery said:

I know EP90 was recommended for D1s and RRCs then from D2 LR started to recommend 75W90 for diffs and transfer case, maybe they've got smarter ... from all the advertisings i've seen EP was recommended for various gearboxes not for diffs... but i'm not gonna contradict the masters on this

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they dont choose oil or service interval lengths for its ability to give a vehicle a 10 year plus life as most of us would hope ,i think the fact 75w/90 is thinner and still able to offer enough lube was more likely reason, ep oils are for high pressure applications a crown wheel and pinion been a good example

So you say the EP90 is better?

sierrafery said:

I know EP90 was recommended for D1s and RRCs then from D2 LR started to recommend 75W90 for diffs and transfer case, maybe they've got smarter ... from all the advertisings i've seen EP was recommended for various gearboxes not for diffs... but i'm not gonna contradict the masters on this

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EP 90 is primarily diff oil. But does have other applications. Multigrade 75W 90 is specified as is any oil meeting the API GL5 specs.. There is EP 90 that meets this spec. Therefore it can be used.

Now all i want to know is which is better for the diffs and transfer case of a D2 cos i want the best for my car that's why in most cases(unless i know different for sure) i'm using what the builder recommends but i can be convinced with serious arguments to use other stuff if it's better.... like for example when it comes to engine oil

Gearbox mtf94/atf94
Diffs and transfer box 75w90

For PAS and ACE use the extreme climate LR issued.

Views?

The dealer book for my LR discovery 2 2004 manual says to use Castrol Syntrax 75w 90 in both diffs and transfer box my question is this:
Castrol - £16 per litre
Comma SX 75w 90 GL 5 high performance- £6.40 per litre (£32 for 5 litres)
Triple QX 75w 90 - £8 per litre

They all conform to GL5

Castrol obviously expensive but is it the best?

Thanks

Any synthetic 75W90 is good the brand is not so relevant

The Comma is winning on price but is semi synthetic does it have to be fully synthetic as the Castrol is?

It doesnt HAVE to be fully synth but it's better, if you know you are changing it regularly your choice though the lubrication is not the area where it's good to save all the money

Mine's a tratter but only ever used EP80/90 in mine, got five gallons of it with a fluid transfer pump !

So, as long as it's 75w 90 fully synthetic and changed about once a year all should be good then. Comma do a fully synthetic too but eurocarparts are doing a deal on the Triple QX fully synthetic so will probably get that instead.
Mr S1 - I've not come across Ep so will stick to 75w 90 as per book.

Catweazle64 said:

So, as long as it's 75w 90 fully synthetic and changed about once a year all should be good then. Comma do a fully synthetic too but eurocarparts are doing a deal on the Triple QX fully synthetic so will probably get that instead.
Mr S1 - I've not come across Ep so will stick to 75w 90 as per book.

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old fashioned mineral oil is more than adequate,its basically the same diff theyve used for decades, especially if changing much more regularly than lr recommend which is far too long imo the synthetic might last the miles of extended changes but it still carries the contaminants