Had my Steering Rack replaced under CarMax's warranty due to it leaking 3 weeks ago. For 3 days it was fine I'm noticing creaking and shuddering sometimes when driving at slow speeds. Higher speeds seems ok.

Previous owner ran slammed as I see a lot of rubbing on the fenders and the screw was cut. Believe that was needed to run some setups. Are the Tie-rods (outer) shot from him running lowered with no stock suspension modifications? The shop didn't replace them when they put in the new rack. My understanding these should be replaced when the rack is replaced per Service Manual. I noticed when tuning before rack replacement I'd get a feeling the outermost tire was skidding a bit sometimes with a clunk. I'm 98% sure it's the outer tie rods. I'm a little irritated they didn't replace them with the rack but probably the warranty company didn't authorize it.

Since the tie rods are ancient I injected some grease into the dust cover boot on them with a Zerk syringe. Again for a few days it was ok, but the creaking is back but not quite as bad.

Is it worth the money to go to a more expensive Tie-Rod, Nismo or SPL? Currently my suspension is OEM stock, but considering some KW coils down the road.