Adjustment in VW1302

Careful checking on the thrust angle in VW 1302 Super Beetle by reading the distance on two centric positions on steering post proved about 1,5mm meaning the discrepancy would be 7 to 10 minutes leading to minus angle with right side running tendency. This discrepant value is contained in the acceptable range of European Motor Vehicle Safety Standards, thrust angle should be so adjusted as to the value of plus minus 10 minutes.

The adjusting point does not exist in the independent rear semi-trailing designed rear axle construction, Super Beetle's specific designing, the outer trailing arm length adjustment is purposed to do on wheel base adjustment. So, after establishing the length on both side, residual lateral displacement of rear axle must be compensated by adjusting frontal axle constructions, strut on either side must be moved laterally keeping a three dimensional parallelism with an original positioning relations.

This procedure looks logically correct but not so an easy task as described like this.
Finally about 2 mm outside movement of left strut upper mount displacement would be done accompanying lower arm adjusting externally on central cam adjusting point, of course toe-in value reduction would go together without description for the last procedure.

Probably much more fixed  and tight centric stability would be obtained after upper adjustment procedures. The steering centric stability while straight running scenery like doing on a rut has nothing to do with the constructive designing, compliance, play nor hysteresis, also the positioning of driving wheels even in 4 wheel driving system.

This phenomena is already proved on torsion beam rear axle designed NCP10 TOYOTA Vitz with muddy and sticky centric steering reaction, this tendency is close upped if it's thrust angle comes to Zero degree. In addition it is often observed in German automobiles with too much negative camber application designing of wheel alignment, also very sticky in centric position but not so bad ride.