The 'E' Type Forum

Like a lot of people i use Valvoline VR1 20/50 in the engine. I wondered if anyone had tried using Valvoline SAE30 non- detergent in a Moss box as I'll shortly be doing a gearbox oil change. Currently I’ve got Redline MTL in there but it does leak slightly

I dunno. SAE 30 is an engine oil designed for small 4 stroke engines like mowers and its viscocity is double that of MTL at 40c although very similar at 100c.

MTL is specifically designed to a be synchro friendly gearbox oil with low sulphur. I can’t find anything about the SAE 30.

MTL and MT90 are specifically designed for our gearboxes and are used successfully by a lot of us in our Jag gearboxes. I guess the question you need to answer is whether you’re unhappy with the performance of your box with the MTL and if so whether SAE 30 is likely to improve it.

SAE 30 is the specified oil for a moss box. BMC & Triumph cars also specified SAE30 for their gearboxes.

Thanks for your thoughts. MTL seems to have a reputation for a slightly improved gear change at the expense of being a bit more prone to leaks. The leaks i get are very minor so i could just carry on using MTL. Ideally I’d like better gear changes and no leaks

I get that Randall and I do actually use 30W engine oil in my MGB gearboxes but that recommendation is from 70 years ago and who knows what formula changes have occurred in that time.

The Redline products on the other hand are specifically designed for gearboxes and have the runs on the board as far as happy customers are concerned.

I just use a modern 20w50 in my moss box, works fine, good shifting when cold or hot.