<<The earlier MGB 3 synchro gearbox maybe a benefit regarding less power
consumed, however; a 3 synchro "D" type overdrive has an extermely small
cone clutch in comparison to the later "LH" type. The average "LH" type
cone clutch will out last a "D" type by a factor of twice.You must trade
off the higher maintenance cost to lower fuel economy. So the issue of
fuel cost is insignificant.>>
I disagree. When used correctly, neither OD unit should require service any
more often that the engine or transmission itself, and so the early unit isn't
really any more costly than the later one.
If you are tearing up the D type unit, basically, you don't know how to drive.
I have used early units on 2 different race cars, one of which has about
double the power of the later wimpy B engines, and have not experienced any
problems. But then I've only been doing it for a quarter century, so who
knows......
A friend that has trouble taking advice has torn up 3 units by driving it the
wrong way. The right way? Just declutch or at least lift off for up shifts
and don't use it for engine braking. Works fine for me, and if I have to
trade off a few hundredths of a second for an OD that will last for years, it
seems a fair trade to me. If you can't drive gently and smoothly, forget the
OD and go for the all synch trans.
Oh yeah - don't hit the switch and shift out of OD when you are already in OD
doing 6500 RPM - another friend discovered that one, bu forgetting which way
the switch went. Exit several valves.
There were, by the way, stiffer springs available once upon a time, for
competition use in the ODs.
Bill
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