Wah, why did u put EK9 rear ARB in the 1st place, unless you're a regular touge man, or SIC wannabee, no need la bro.
But if you still insist on installing 'em, then like JINEIL2EN said, better check the installation, is it correct or not, And your endlinks, in good condition or not ( since EK9's rear ARB is 21 or 22 mm, I forgot ) as the force from the larger ARB is a lot more than standard ARB.
And cOOlric is correct oso, you must reinforce the mounting area via installing some sort of aluminium plate, I don't think it's locally available here, and it's not available at SG oso. You have to order 'em from the States, brand A-Spec Racing ( ASR ) is currently one of the best ones available.