30 wt oil (I use Penrite HPR 30) is just perfect. ATF is also
perfectly fine as well. I have heard from somewhere that Mobil 1 is
not a suitable oil for manual transmissions because of a lower shear
strength. This is unconfirmed. Any further comments on this?
You definately shouldn't use diff or hydraulic oils in gearboxes that
have bronze syncros or bushes. The high sulphur content in gear oils
(whicj makes them work well under extreme pressure) react with the
bronze. Spridget boxes are a good example, particularly the
smoothcase boxes.
50 wt oil isn't really a good idea. The synchros rely on being able to
bite, with 50 wt oil, the oil will take longer to squeeze out from b/n
the faces before the synchros can work. You'll either have to make
significantly slower changes or match revs well. The local gearbox
guru (John Needham) berated me for using 50 wt in my smoothcase
straight cut C/R gearbox on the ex-fluoro race spridget.
BTW, one of the correspondents on this issue had a supposed Mk 1
Midget with a '65 title. It is either a Mk II Midget or a false title.
You can check which by examining the rear suspension. No false ID
plates or title can hide the difference b/n a 1/4 elliptic and 1/2
elliptic rear suspension!
Mike
_______________________________________________________________________
Mike Gigante
3D interactive graphics, Virtual Reality, british sports cars, and wine
http://mega.cgl.rmit.edu.au/~mg/ mg@mega.cgl.rmit.edu.au
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