Lotus Elan and Lotus Elan Plus 2 Forums

Afternoon folk
Just got back from picking up a couple of cranks and the guy i'd bought them from asked me if I knew if the diff casing (see pics) was a mag alloy one? It was 1/2 - 2/3rds the weight of a normal alloy one, and had the extra number M 40139 cast in below the standard Lotus part no. It also had four extra lugs inside, presumably for an LSD. Any ideas what he has?









Looking forward to hearing your views!

aluminum density ~2.7 magnesium density ~1.7, plus the darker Grey color (natural oxidation) speaks for magnesium... a bit of added lightness for a racer, though not a lot compared to the stock version (is it for sale?)

The lugs inside look to be there to allow as much material in the casing while making (minimal) room for the 4 differential main cap bolt heads. They can't be to hold anything as you wouldn't be able to get to them once the diff pig's head is installed.

Looks a nicely made thing, probably really only any good for an out-and-out racer.

Looks like my 26R ones, same casting material difference only, back dichromate coating etc

V

vstibbard wrote:Looks like my 26R ones, same casting material difference only, back dichromate coating etc

V

one can note small casting differences with some similar parts currently being offered (though I don't know if there have been variations along the years) - no affiliation on my part



https://www.tonythompsonracing.co.uk/pa ... -26r-spec/