I was feeling that my bike's rear end had become a lot wobbly recently and went for talling the rim. However, the mech told me that the suspension bush has worn out and needs to be replaced. Another authorised HH service center said that it can be fixed by using a lathe, costing around 400; a new one would be around 1700.

I checked the net and it seems to say that the suspension bush is a rubbery thing. Can someone explain me what the thing is and how can it be lathed if its a rubber thingy? Also, any particular reasons as to why the thing got worn all of a sudden? I have been trying to pull wheelies off recently. Can that be a cause?