Gearbox oil

Post by **chilly** » Fri May 09, 2008 5:16 pm

I've been trying to buy some SAE 30 engine oil for my gearbox today to no avail.
I notice that lawnmower oil is SAE 30, is it OK to put it in the moggies gearbox?

Post by **WPR678B** » Fri May 09, 2008 5:39 pm

20/50w engine oil is what is recommended for the gearbox.

Post by **chilly** » Fri May 09, 2008 5:45 pm

WPR678B wrote:20/50w engine oil is what is recommended for the gearbox.

All my workshop manuals say SAE 30 but having done a search on here it seems 20/50 is the oil of choice. I'll go back out and traipse round all the shops and motor factors again to see if any exists in town!

Post by **dalebrignall** » Fri May 09, 2008 8:04 pm

it does say 20/50 in the books,although sae 30 should be available from your motor factors.commer oils do straight oils

Post by **jgunson** » Fri May 09, 2008 11:52 pm

Comma Oils do a SAE 30, SAE 40 and 20W50 oil for classic cars at a reasonable price (www.commaoil.com). My manual states SAE 30 also although the preference within this site does seem to be 20W50 which does have a wider temperature tolerance and a longer life (in the engine).

Post by **Kevin** » Sat May 10, 2008 12:27 am

The original oil was S.A.E 30 but progressed to 20/50 if you have the full list of oils (even the haynes manual has a pretty good list) , 20/50 is a proper multigrade which is correct for both the engine and gearbox and was a later development and gives better protection than the straight oils.

Post by **chilly** » Sat May 10, 2008 10:05 am

Thanks all.

20/50 it is then.

Post by **bmcecosse** » Thu May 15, 2008 11:39 pm

Your lawn mower SAE 30 oil would be fine. Slightly thicker when cold but thinner when hot which may help with slightly less drag in the box and so better MPG. But I agree - most just use 20W50. You can also buy MTF oil at 30 SAE which is Manual Trans Fluid and this was specified for many later Rover gearboxes - it's just engine oil without some of the detergent additives but strangely costs more!