Oil grades

[Mike M]

I did read about oil grades somewhere in the forum, but cant seem to find it again. I own a Austin 12 New Ascot.
So may I ask, my handbook recommends Castrol XL for my engine, Castrol XXL for the gearbox and Castrol D for the rear axle. I have read that the equivalents today are SAE 30 for the XL, SAE 40 for XXL , albeit the club recommends SAE40 for both Engine and gearbox for all year round. Is my understanding correct?

Can anybody advise me what the equivalent grade for Castrol D is ?

Thanks

[Rod]

Others will most likely have other suggestions, but FWIW on my Goodwood [in New Zealand] I use:
-Penrite Transoil T140 in the rear axle, this is labelled as safe for ferrous and non ferrous metals, also safe for leather seals.
-Castrol Syntrax Universal in the gearbox, probably overkill but I had access to some redundant 1 litre packs of it at one time.
-Generic 20/50 engine oil, but I **thoroughly** de-sludged the engine before using it [sump off etc]
-I also use Penrite Steering Box lube, not only in the steering box, in which it has proved 100% effective in eliminating leakage, but I also use it in the grease gun for the chassis, I find it is less likely to take the 'line of least resistance' and it will actually lubricate the entire bearing that you're trying to lubricate, be it brake compensators or king pins, rather than leak out through the biggest clearance...

[peter_winney]

Mike

Yes you are right. Austin handbooks for the 1936-39 models recommend SAE30 for the engine and SAE40 for the gearbox. Earlier handbooks recommend SAE40 for the engine in summer and SAE30 in winter and the club has followed that advice as a recommendation for all years. Later engines have shell bearings which may account for the change in Austin recommendation.

Some, including myself, have always used classic multigrades 20/50 but the club cannot recommend these as they are not inline with the original manufacturer's recommendations. The detergents in these are said to be bad for our engines in that they can shift old crud from where it has accumulated in the oil ways into the bearings. Probably the most important thing is to change the oils regularly - if mileage is low at least once a year.

Castrol D for the Austin back axles is D140. There are many sources of supply. Check the availability and prices (including any VAT and P&P) to get the deal that suits!

https://www.classic-oils.net/Castrol-D140

https://www.opieoils.co.uk/p-77271-cast ... types.aspx

https://www.holden.co.uk/p/castrol_clas ... 40_1_litre_

http://www.classiccaroillondon.com/prod ... trol-d140/

Penrite makes good quality oils widely used by professionals in vintage, thirties and classic car businesses. Other makers of classic oils include Miller and Morris Oils both long established.

The steering box has 2 lubricants - a nipple for grease and a removable cap for D140. You may find an oil can pump with a flexible spout essential to get at that one.

[Mike M]

Thank you both for the valuable information, much appreciated.
Mike

[Mike M]

Just one further question in regards to the gearbox. The capacity is 4 pints according to the handbook, but the handbook refers to a filler cap/dip stick. My filler cap is on the top of the gearbox and has no dip stick. Apart from just measuring 4 pints, is there a correct level when filling or checking the oil using the filler hole?

[mashby]

For info i have used the following oils for the past 40 years on ACL 80 Austin 18 York 1937

1) Engine: Castrol 20w 50 GTX or Classi 20W 50. after engine rebuild so no sludge, Hardly ever changed filter (as hard to get) but regular oil change
2) Gearbox: SAE 40 or 50. Use SAE 50 in France at high temps. The A18 suffers from throwing oil over clutch so SAE 50 Helps, SAE 50 is approx same viscous of modern Gearbox oil. (RE: Castrol Syntrax is a fully synthetic oil which maybe an issue on some brass bushes??)
3) Rear Axle: Castrol Agri EP 140. Great supply from Ernest Doe. Tractor axle oil!!

[peter_winney]

Just one further question in regards to the gearbox. The capacity is 4 pints according to the handbook, but the handbook refers to a filler cap/dip stick. My filler cap is on the top of the gearbox and has no dip stick. Apart from just measuring 4 pints, is there a correct level when filling or checking the oil using the filler hole?

Does your gearbox have another plug half way up on one side? I am not an expert on the model but I believe some Lt12 gearboxes have an "overflow" plug on the side so as to prevent over-filling.

[Mike M]

Hi Peter,
I've been unable to locate any overflow hole on the side of the gearbox, however I will have another check once the car is raised up on axle stands. If I can find one then that is the answer sorted. I will update the post later this week when I work on my car. Thanks for your assistance so far, I've only acquired the car recently so just figuring things out as i go along.

[peter_christie]

Hi Mike M,

It would be helpful if you would quote your Chassis Number. Your handbook refers to the gearbox having a combined Filler Plug & Dipstick. It may be that you have the wrong Handbook or that the Dipstick has become detached from the cap or Plug. The Overflow Plug on the right hand side of the Gearbox is present on cars built before November 1938, the boxes with the Dipstick were fitted to Series H/RA, H/RB and HS1 including wartime and immediate post-war production. If your car has a Pistol Grip Handbrake then it is Series H/RA
The Engine, Gearbox, Steering, Front and Back Axles and even the Starter motors on cars of Series H/RA are completely different from the items fitted to Series H/R cars.
If your Chassis Number is above 61434, your car is fitted with the later Engine and Gearbox.

I hope this is helpful

Peter C. [6515]

[Rod]

Re: Syntrax and yellow metal components, this product is actually rated GL4/GL5 & MT-1 and is also specified as synchromesh transmission friendly on the pack [I know there is still some ambiguity about GL5 oils being suitable for earlier transmissions].
Off Topic: We used to use it successfully in the transmission of a well known light commercial vehicle which tended to suffer from both gear wear and poor synchoniser action using the OE fluid. Especially if it was operated in too high a gear for the load/overloaded.