Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Lopsided Plus 4, weak rear spring?

One way to check for lopsided or equal sag at the rear is to check the vertical clearance between the underside of the axle and the chassis cutaway where the rubber rebound stop is. Do it on flat level ground and note that with the car stationary the front suspension will significantly control roll attitude, so make sure the front suspension is at the same height both sides by checking the length of the rebound springs at static ride height.

OK this clearance varies between models and years, but if it is much more than around 30mm unladen then the chances are that the springs have sagged. You will get a good idea with the two finger in the gap trick, is that a rule of thumb? Regards PJB.

Spot on PJB.
Basic protocol I believe is:-

1) Car should be on flat ground.
2) Remove any luggage or other items that are not standard.
3) Check the front suspension is operating properly (this has caused problems down here)
4) Measure the height from floor to chassis each side below the middle of the rear axle centre between the U bolts. This instruction is taken directly from item 4 in the Morgan Classic models chassis measurement instructions – October 2011, PM me with and email address if you need a copy.
5) Make sure tyre pressures all round are as per the book.
6) A good indicator is to measure the vertical distance from ground to the edge of the wheel arch through the centre of the wheel hub and note the difference.

It might also be worthwhile checking if you have any statutory ground clearance requirements in your part of the world - you don't want MOT issues. (ie, The Morgan specified ground clearance for a +4 is 100mm http://www.morgan-motor.co.uk/sales/plus4.html)