2 reasons one replaces as whole assemblies ~~~ cost is close to buying individual tie rod ends and the time and frustration of trying to get the old ones out of the sleeve (most are really frozen in there)

center link = drag link ~~~ i'd replace that along with the steering damper if it has any age on it ~~~ pretty cheap replacement parts

idler arm normally comes as a bushing kit, cheap also

replace all that and your steering linkage should be good for another 100k

watch your quality on all these replacement parts though

__________________
1989 300ce smoke silver / brazil, in a constant state of flux ~~~