Lagonda Rapiers

5 minute(s) of a 484 minute read

There were the two main suppliers of Pre-select transmissions in England during the 1930s. Wilson and ENV. Both transmissions were made under Wilson Patents. The ENV 75 box as fitted to the Lagonda Rapiers was slightly smaller and lighter than the Wilson equivalent.  The gear selection was in a straight line with a lock out latch for reverse otherwise the principal was the same as on the cord. The Rapier's gear lever was floor mounted originaly the drivers right hand side. This was moved later to a centre position with the gear selection lever moveing in a straight line with Reverse furthest forward with Netural next then as the lever mover back first, second, third and top. This acted on a small lever on the left hand side of the gear box. This in turn rotated a "cam" shaft that pre-selected the require gear, depressing the pedal in the same position normally occupied by the clutch. This pedal depresses the large spring seem in earlier photographs allowing the strut for the next selected gear to move so that its "foot was sitting on the "Bus-bar". As the pedal was released the spring tightened the band controling the next set of gears and thus bring them into action.   Gears are epicyclic revolving around a drum. By stopping the drum from rotating caused the planetery gears to revolve inside the selected drum in turn transmitting the drive via a central "Sun" gear this then took the drive to the rear wheels. Unfortunately to fully explain the principle required would take far too much space and time.
The photographs below show the gear selection lever with the reverse lock out. The final photograph also shows the there pedals with the "Change"pedal on the left, the accelerator the small pedal in the middle and the foot brake pedal on the right.
The last two photographs show the layout of the planetery gears inside the drum. The final photograph shows the complete "gear train" with a "soup tin" to show it's comparative size.

OK I am sure you are all anxious to learn more about these fascinating transmissions so I have gone back to square one,
The ENV 75 supplement to the original 1934 Lagonda Rapier "Owners Hand-book". The drawings contained therein will explain the workings far better than I, a humble, uneducated lay-person. If nothing else it may help you appreciate where all those fascinating whirrings and whining come from. To move from a simple straightforward non-synchronised "crash" gearbox of the 1920s to one of these just three or four years latter must have had many of the mechanics of the day, scratching their heads.\
At first glance it may appear as though I have duplicated the drawing on "Plate one". This is no so.
Please look again.

It is one thing to be able to look at the drawings and understand why it should work. It is another totally different thing to take one apart and put it all back together so it will work.