scotty boy 1

I scot If i were you I would post this into the defender section probley get more reply's in there

hi all, i bought a 1999 110defender td5 with 138000 on the clock couple of months ago and just had to replace the fuel pump and now im worried something may be wrong with the gearbox. im not mechanicaly minded so hope you may be able to help. symptoms are:
clonking noise from underneathe whilst changing gear.
all gears are smooth except for 3rd which sometimes knocks when engaging.
slight delay in acceleration through gears(occasional).
i am abit concerned as im abit short on funds at the moment and worried about how much this may cost. any thoughts would be appreciated.
thanks in advance,scott.