Replace your C3 with a A4LD
By John Hodgson
If you are using a Ford engine (in-line or V6) then
rather than sticking with the C3 its just as simple to use the A4LD 4 speed.
There are two advantages over the C3. First: By playing around with final
drive ratios, its possible to improve 0 to 60 without loosing top end.
Second: improved fuel economy
As they are an evolution of the European C3, they
share a great deal in common. If you are using the oil cooler built into the
radiator from your C3 then simply swap the brass pipe unions over between
the C3 and A4LD, This will allow the C3 pipes to be retained.
The box is longer than the C3 which means shortening
the prop. But by using various front/rear combinations of the 2 piece Ford
propshafts (which are easy to separate in the middle) you can achieve a
number of different lengths without cutting and welding.
Due to the extra length the rear mounting is pushed
further back, however, I am about to look at a curved (Boomerang shaped)
bracket from the manual Cortina (3, 4, 5). It looks like it could be the
right size to line up with the old C3 body mounting points.
The mechanical Speedo drive from C3 simple replaces
the electronic speed sensor.
If you find an early A4LD some had a mechanically
locking torque converter. Later ones have an electronic one, however, this
doesn't effect the normal running of the box if not connected. The C3 torque
converter will fit the A4LD box if required. However, take care if using
behind a 2.9 engine as the 2.9 drive plate is not compatible with the C3
torque converter as there is no hole for the drain plug. Although C3 (2.8)
drive plates can be used with the A4LD.
Kickdown on later boxes is electric, however, simply
use the pedal and cable from the donor car. all the kickdown requires is a
wire to the switch (which is built into the cable) to the solenoid and one
to the battery, although, I prefer to connect this via a relay so that the
switch activates the relay and doesn't take the load of the solenoid
Avoid late boxes (91 - 92 onwards) as these became
fully electronic and require serious wiring taking signal from the engine
sensors and ECU.
Always check and replace the front oils seal before
fitting. leaks from here are common.
A beefed-up version of the A4LD sits behind the 4.0
Cologne powered Explorer and Ranger. Later becoming a 5 speed and
Boxes fitted to in-line engines have different ratios
to the V6 units.
Later 'T' shaped gear selectors are about the same
size as the old C3 unit. early offset gate type selectors require a larger
hole in the floor.
Early boxes can be soft if pushed hard.
John Hodgson More info here