Squeaking again (fixed by WIMs)

Does anyone know of a way to stop shocks squeaking?
I’m on my 2nd set of rear Gaz shocks on my MK2.5 and they have started making a creaking noise like the titanic going down!
If I adjust the damping from 16 up to 20, it changes to a high pitch squeak.

I’m afraid from my experience that is standard, that’s why I’m not on Gaz anymore.

 Took the car in to WIMs yesterday, and excellent service as always.
 The two Tony’s had a look under the car and found the source of the squeak/creak.
 
The FM ARBs were twisting inside the Poly Bush mounts, which had dried out.
Tony removed them, put some white grease on & problem solved.
 
As I was there, I got the Geo done again & unsurprisingly with the state of the roads around surrey, it was slightly out.
All sorted now. [:)]