I’m going to be attempting to change the rear tie rod bars i(control arms) on the fatty I was thinking of undoing the bolt at the bottom of the dampener to see if its fubar by checking if it has any resistance would this work 2012 Range Rover Westminster 4.4 TDV8
2006 Discovery 3 HSE 260k miles and still going strong with a new owner

You should be able to tell by the way it handles if a rear shock has failed. Mine were very stiff after 170k miles and could only compress them with my full bodyweight when off the car so unless they have lost all thier fluid I doubt just removing the bottom bolt will tell you anything. 2012 TDV8 Vogue (L322)

You can get them checked on the vehicle - I have used this service on a 911 previously and if you really wanted to know the actual state of health of your dampers and even how they are matched side to side, then this is the only way to do it scientifically.

https://centergravity.co.uk/workshop-services/#damper

[edit] They are based near Atherstone, so not too far from Leicester; they usually want to do a full check and report, but might be persuaded to just test your dampers on their floor plates if you ask them nicely... 2011 Range Rover Vogue SE 4.4 TDv8

Hi, Another way is to drive over full width speed bumps slowly, say walking speed, you'll tell by the way the car reacts whether one side is damping better than the other. Or of the car bounces excessively then both might be gone, or doesn't bounce at all then one could be siezed, rule of thumb is 1 bounce then settles.

Get a friend to do the same in your car as you may think the behaviour is perfectly normal as you have got used to it, another driver unfamiliar with your car would easily spot something out of the ordinary as their expectations would be different.

The traditional bounce on the corner isn't going to do anything on a Range Rover unless you're quite weighty yourself and you'd have to do with the engine running to make sure everythingis primed.

If you remove them from the car and you can compress them easily that tells you they're probably shot. You can't really hand prime shocks like you used to because gas ones should be constantly under pressure.

If you remove them both you could to a basic comparison check by clamping them in a vice and applying a fixed weight to compress them, i.e. 50kg and measuring how much they actually compress. Not at all scientific but will tell you whether one is leaking more than the other but more likely you'll hurt yourself in the process. Fuji White / Jet 2012 4.4 TDV8 Westminster

I understand the CVD shockers default to fully hard if no voltage is applied, or if the car isn’t actually moving….

…..if that changes anything diagnosis wise off the car…. Or car not moving….

 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport