Morris Minor Owners Club

Had to change the rear suspension arm (RH front) and hence need o reset the new arm on the torsion bar. There is a method quoted in the workshop manual but in the MMOC Technical Manual there is a simple way of setting the ride height "Measure from the hole in the end of the arm to the bottom of the round hole in the inner wing......the distance should be 17 inches +/- 1/4" I cant get anywhere near 17" in fact on the other (unmolested) side the distance is 15" with the suspension hanging on the lower bump stop.
I'm obviously an idiot but any clues what I'm doing wrong

I dont know the dimension you refer to, but it is probably a 'free' measurement ie not hanging on the lower bump stop

Rule of thumb is that with standard wheels you should just be able to put your hand vertically between the top of the wheel arch and the top of the tyre.
Reading the manual seems to suggest that you have to reset the torsion bar. It may be easier to do a trial assembly, loosely clamping up only the bolts necessary to keep the assembly together, ie don't bother with the tie bar and central clamping nut and bolt, and letting the car stand on its wheels. Measure the distance from the front corner of the chassis leg to the ground on each side and adjust the lower arm accordingly. One spline will adjust the suspension height by 1.5in. Before removing the arm to adjust, mark its position with tipex or similar as a reference point.

the measurement of 17 inches is a free measurement

As long as the arm is moving easily on the T bar splines - it's only moments work to shift it round a spine or two - and then try again on it's wheels. As above - don't bother to connect up all the gubbins at this stage! DO expect it to settle slightly anway - so if anything - set it up slightly high,