Track rod is the same as tie rod Assembly. Tie rod end would be the ends only. The center is the adjusting sleeve. The ends are different [ R /L] b/c the threads are either R or L handed...Buy the assembly,it is easier and if one is gone , the other is soon to follow.......... Adjust the lenght of the unit to match what you took off for approximate alignment..but proper alignment is required after changing these parts [ toe in/out]

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A Dalton