Jerky transmission reversing Big Seven
Transcribed from 'The Austin Magazine' April 1947 p371.

Dear Sir . . . . .

My car is a 1938 Austin Big Seven and I should appreciate your advice in respect of a fault which the car has recently developed.  When I reverse the car there is a very definite shudder or jerkiness in th transmission immediately I release the clutch.  The fault is particularly noticeable if the car is reversing up a gradient and I am wondering if the clutch unit is in need  of some adjustment or renewal of a worn part.

From the information you have supplied it appears most likely that the rear axle torque tube ball joint adjusting ring needs tightening.  This joint will often wear considerably and unless the wear is taken up by the adjusting ring there is a tendency for the propeller shaft to judder when the car starts off from rest.

To adjust the torque tube ball joint remove the two securing bolts locating the adjusting ring in position and screw the ring as far as it will go in a clockwise direction.  Then release the ring one notch and secure again by the two locating bolts. The joint should then be well charged with oil through the oiling plug, accessible from inside the car by removing the cover over the propeller shaft.

The possibility must not of course be overlooked that the jerky transmission you are experiencing may be due to oil reaching parts of the clutch linings in which case it may be necessary for new linings to be fitted.  The cause of the oil leak will also need to be eliminated and this mat involve extensive overhaul.

Jerky trans Big7

See also:

Hardy Spicer Propshaft Overhaul