[zxdragon777]

Probably the spring has snapped and a piece broken off so it's not locating properly as it will be incorrect size and location once broken I had this happen a few times small pieces at the end kept snapping off so the springs would not locate in the end locking plate as well as breaking elsewhere more obvious all I knew was it not handling very well over bumps and unstable on the road .
I had several springs replaced on my Corsa then i changed the whole lot to a Company called KYB .
If you are doing the work yourself I would order a new spring ( I always replace in pairs , but for now you could just buy the side you need they are cheap enough £10-15 I think KYB were about £20 several years ago , but not had one broken since I had about 7 replaced under warranty the lousy Dealers only ever replaced singles in fact before the warranty was out I decided to replace the whole bloody lot and get rid of the cheap crap Vauxhall installed at 15k miles the front shocks were buggered and leaking yet another front spring had snapped despite being on the car less than 3 months since they last replaced it . ( to be fair I was lucky the parts supplier manager at the local Perry's branch advised me over KYB as I was enquiring if there were any higher quality springs I could purchase myself he told me not to bother with Vauxhall stuff and get a decent KYB or BOSCH replacement
I did the whole lot front and rear new shocks new header bearings all standard spec ( not lowered or uprated ) now been on the car 14-15 years never had a problem since the first 2 original years car is now 17 years old and rising 2004 Corsa 1.3cdti
Car was like new when I had this work done still got the reciept parts were KYB front shocks x2 £68 +vat , 2 x Header bearings £45 + vat , 4 KYB springs £60 + vat from Ray's car supplies in Accrington . Roy at Surestart motors Bury Lancashire charged £80 fitting