Seriously it is a piece of piss - even your Mum could do it
.
Jack the car up, so the weight is off the rear springs (use the rear diff to jack it up on). Place axle stands under the car for safety and then take the rear wheels off.
You will be confronted by this (this is the front of mine, but is just to show you the spring preload collar). All you have to do is wind this upwards (ignore the grease, I had a split gaitor
):
I would do it 1" to start with (both sides) and see how it goes.
You will probably notice on the nearside (the side closest to the path / hedges as you drive), the spring will be rubbing somewhere on the inner wing (you will see a shiney part where this has been happening). This is common to all Cosworths, and you need to beat the shit out of the inner wing where it rubs with a fuck-off big rubber hammer (be carefull not to hit the outer wing
) to give some clearance, as this will be the source of some of the noise
. Also apply some grease or copper slip to this part of the spring if it is still skimming the inner wing, as this will stop it from squeaking
.