Replacing Rear Shock Absorbers

[MinerWilly]

Whenever I have people in the backseats ( lol sounds dodgy this ) or even a fat mate in the front of my car there is a kind of groaning noise coming from the back corner when moving off and when going slowly over damn speed bumps , I am new to driving so please understand my ignorance .
I reckon it is the rear left shock absorber that has gone and have decided to replace it myself as the MOT is due end of July , I have the Haynes manual and it seems a pretty simple job . Originally I thought I was going to have to compress springs etc and stupidly didn't realise they aren't connected at the rear , the only tool I don't have is a torque wrench .
Anyway my question is would you recommend changing in pairs or should I just change the (hopefully) broken one? Would you bother getting a couple of old ones from the scrappy and if not are these ones on EBAY any good ?

http://cgi.ebay.co.uk/Pair-Rear-Shock-A ... 1|294%3A50

Is there some kind of inspection do to tell if it is actually broken before shelling out money etc ?
Also if you think the problem maybe something else entirely different then please give me your thoughts . thanks .

[haydn1987]

push down on the car next to the wheel that you think needs replacing if it bounces up and down and takes a while to settle then it needs replaceing, but I don't think this is what is causing your problem.

I very common problem in the corsa is the exhaust touching the rear axle, when you have people in the back of your car the suspension lowers and the axle gets closer to the exhaust if it touches you will get a horrible rattle.
Mine used to do this but only when moving off and at low speeds this is when the exhaust shakes the most, I got a clang if i when over a speed bump a little too fast.
If you get a few fatties to sit in the back of your car you will see where the exhaust gets close to the axle.
The bit that is closest to the axle is where the centre section joins to the back box and a clamp is used to hold the two bits to gether, most of the time its the clamp that touches the axle, if you loosen the clamp you can move it a bit to give more clearance.
Try replacing the rubber hangers that hold the exhaust up they are just behind the rear bumper and don't cost much.

[mobiius]

I'd recommend changing them in pairs yes.

[MinerWilly]

Thank you gentlemen , very useful tips , after typing original message this morning I went out before during lunch break and gave it a good bounce on each corner,I opened boot and really pushed down hard on rear and they do seem to settle all as quickly as each other .
I gave a mate a lift home from work (another big fella !) and yea he sat in front and whilst moving off or running over bumps I would get the kind of groan noise (not really a rattle like earlier this year when i had a broken front spring . ) It doesn't make the noise when on smooth surface .
I got a trolley jack and stands last week for a tenner from Wickes and am going to take a look at exhaust asap . My Dad recently only just got rid of his Corsa B it had over 270,000 miles !!! and was from original run of Corsas . He also said to me it could be something to do with the exhaust/axle as it once happened to his too . Thanks for advice , and any more opinions would be appreciated .

PS- Anyone know of a reputable company where I could Hire 3 fatties for a couple of hours to do the experiment with the exhaust ?

[MinerWilly]

I got under the car today and got somebody to bounce it around a bit and it doesn't appear to be the exhaust the little rubber clamps all appear fine etc . The noise is definitely coming from around the back left , does this mean that shock has gone (or is on way out possibly) ? anyone else know of anything else that could be causing this weird groaning noise when people get in car or when going over bumps ??