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An important point to observe here, prior to commencing repairs, is in regard to the front suspension
cross-member. Correct alignment of the front suspension is of such vital importance that if there is
appreciable distortion of this member it should be renewed, due to the fact that it is a very difficult
operation to re-form it to its exact shape.
NOTE. —We do not recommend that this operation be carried out by the Distributor or Dealer
unless adequate assembly fixtures are available, but that the frame be returned to the Service
Department, The M.G. Car Co. Ltd., Abingdon, Berks.
R.2 INVESTIGATION OF DAMAGED CHASSIS
Although in most cases of accident the resultant primary damage to the frame is readily apparent,
there are cases where the damage may only be slight and is masked by the wings and body structure,
and in such cases, it may be necessary to carry out a complete check of chassis alignment, including
front suspension and rear axle, to determine the full extent of the damage.
When checking cars damaged in accident it is most essential to do the checking on a flat surface large
enough to receive the complete car. It is preferable to use a large iron slab, but a concrete slab
carefully prepared and hand-surfaced will be suitable. The car may then be directly checked by
comparative measurements, or a centre-line dropped down from the front and rear centre of the frame
and parallel track lines laid out. From these lines the squareness of the car may easily be checked.
R.3 A TWISTED FRAME
Checking the alignment of the frame bare is relatively a simple matter, especially if the frame can be
set up on a large flat surface or face plate. It involves establishing a datum or centre-line, from which
all measurements can be taken. Diagonals are checked from suitable fixed locating points, which can
be cross-checked at the centre line on which the diagonals should cross, as detailed in chassis
dimensional drawing Fig. R.1. The angle of the front cross-member should be 4 degrees but may
given an allowance of +1° or -0°. Diagonal measurements quickly determine which section of the
frame is bent.
Accuracies of side-members are usually checked with suitable straight-edges, and squareness of side
rails is checked with straight-edge and square. Twist is checked visually against straight-edges laid
transversely across the frame at suitable points.
In the event of the frame being twisted, this condition can be corrected by anchoring the frame to a
fixed trestle and by using a suitable lever or a stout beam of timber. The frame can then be sprung
back with effort applied at the end of the lever.
If necessary, apply a well-spread heat at the twisted section.
The frame being completely dismantled, it is possible to remove all signs of damage by cutting out
holes for access in the inner liner plates with the welding torch, hammering out bulges, dents, or
buckled areas, and closing the holes by welding in the piece previously be removed. The welds can be
cleaned up and the repair is then invisible.
When any adjustment to the frame is carried out do not forget the light gauge of the material.
Final checking of the frame should be carried out in accordance with the dimensions and diagonals
indicated.
Comparative vertical measurements should reveal any frame twist.
Check the wheel camber, castor angle, king pin angle, and front wheel alignment.
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