ribbed gearbox oil

[estepona1999]

Can someone tell me which oil to put in my ribbed gearbox please,thanks Roger

[philthehill]

20W50.

[estepona1999]

thanks Phil,much appreciated

[bmcecosse]

The Manual tells you SAE 30 oil.

[philthehill]

The early manuals stated a straight 30 grade oil for the gearbox.
In section PP issue 11 of the later manual it states that approval is given for the use of 20W50 oil in the engine, gearbox, oil bath air filter (where fitted) and carb.
Therefore a 20W50 oil is perfectly acceptable for use in a Minor ribbed gearbox.

[estepona1999]

Thankyou both again,I have been told today about the sae30 being the correct oil,though so many have said it is fine to use 20/50 oil. Is sae30 a thicker oil or the other way round?

[dalebrignall]

the sae 30 is for earlier cars 20/50 is what you want to use

[James k]

I put a can of STP in with the oil when I last changed it. It made a noticeable difference believe it or not.

[IslipMinor]

When the Series II Minor was introduced in the 1950's, for the first time with the same oil as the engine in the gearbox, multigrade oils were in their infancy and certainly did not span the range that modern oils do. So at that time there were different oils for winter and summer.

Roll forward some years and multigrade oils have become the norm, with 20w/50 becoming the default standard engine oil and replacing most of 30/40/50 single weight oils that used to be specified. There is nothing wrong with using a later spec oil in an earlier engine or gearbox.

Our original 948 engine was re-bored after ~4 years and ~30,000 miles in 1962 and needed a replacement crankshaft at ~45,000 miles in 1967. During the 70's the engine was progressively modified and that same standard crank is still in use in a Frogeye Sprite today, in a very well modified 948 engine, with no regrinds and more than 70,000 miles, thanks largely to the development of oil technology.

Our 1380 has a standard crank and almost 70,000 miles, with very little evidence of wear, thanks to modern synthetic oil technology.