Differential Oil

[rwilliamson36]

Hello, 

Can anyone advise on the best oil I should use for my 1937 Austin Ruby?

I would like to order Millers Gear Oil (as recommended) but it has resulted in becoming quite expensive to ship to Northern Ireland - would anyone recommend anything else? I am only looking around 1 Litre of it.


Thanks Raymond.

[Hedd_Jones]

Castrol D140

Morris AG140 or 680 Cylinder Oil (straight or compounded)

[David Stepney]

Any reasonable quality straight (i.e. not EP) SAE 140 gear oil. I am using some that I bought off ebay from Westway Lubricants. Mind you, I change it every 5000 miles, but, so far, no problems.

[bystander]

Castrol D140 is the stuff to use - I would be surprised if it was not reasonably easy to find in NI. Castrol EP140 would do as an alternative if necessary.

[Bob Culver]

This topic has been raked over and over. Through the 1950s to 70s most garages had full EP 90 and 140 and that is what all cars got, Sevens included, when they were very occasionally serviced. (I have seen a few with the pinion teeth worn right through. Presumably the deaf owners never checked the oil)
Early EP oils were claimed to corrode copper and hence early bearing cages and side bushes.  Despite an enhanced EP action, most modern manufacturers claim current readily available full EP GL5 do not corrode esp at the modest bulk temps in an Austin diff transmitting 20 bhp or much less (cf 300 in a truck.)
I suppose some cars may still have bronze caged bearings.
Has anyone encountered cages crumbling like old plumbing fittings? Or side bushes very worn despite smooth axle surfaces.
Has anyone irrefutable evidence of damage by a modern full EP oil from a major manufacturer?
My car has a Regent or Remax cw and p with what seems to be a soft cw. Quite worn in despite full EP. dunno how it would have fared on a low or non EP.

[SJT]

Hi,Ray.
I use an oil shop between Carryduff and Lisburn he operates in an industrial estate about 2 miles from Carryduff on the left hand side of the road.From memory take an empty can with you and he will sell you the amount required, there is also a company in the North Road industrial estate in Newtownards who do classic oils I cannot rember their name but they are very helpful,they are agriculture parts supplier.

Stephen Thompson.

[Reckless Rat]

Assuming it's a D type axle you only need 250ml so a litre can will last you ages.

[rwilliamson36]

Hi Stephen 
               Thanks for your help, the company on the North road Newtownards is called Powertran I never though of them, also another friend who collects tractors told me about that place on the carryduf road as you have said I will try these places thanks again for your help.Ray

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Hi Guys
Thanks for all your reply’s great advice and help, this is a great web site with great advice.

[David Stepney]

I keep some SAE 140 in an oilcan, as this is the best way I have found to get it into the rear diff. However, the fact that it is in an oilcan means I use it for topping up the steering box ( seems to stop unsightly grease marks on your trousers!) and for general oiling duties underneath. I reckon that the thicker the oil, the more likely it is to stay put.

[Bob Culver]

Thinned a bit EP140 works as a cutting oil, esp with parallel parting off tools.