Update on Tie Rod Ends:
Here is my solution to some of the obviously inaccurate and vulnerable to error suggestions regarding replacing your tie rod ends:
The method I used will work providing one factor is true.
That your front wheels are at least adequately aligned already, before you start. If you've been driving them without problems (like oddly worn tires or pull to one side) this is a reasonable assumption.
You can do no worse than replace a tie rod end and leave your alignment intact, whatever state it is in.
You may always opt to have the toe-in checked/adjusted again later.
(1) The first key is to realise that there are TWO factors that will put your alignment out during a replacement:
(a) screwing the tie rod end on too far or too near.
In my case, I noticed that there were TWO possible replacement parts available: a 'stock' part that seemed to be the same as the one on my car, and a replacement part that had a grease nipple. I chose the one with the grease nipple, so that I could maintain its condition longer. But there was a slight difference in the casting between these two parts, which would affect the distance that the locknut on the tie-rod would end up at.
Its important to realise that the critical distance is not determined by the position of the locknut, but by the position of the ball-joint along the tie rod.
The position of the ball joint is what must be maintained, to keep the same alignment, and so the old position of the locknut is NOT a reliable guide. All methods which use the original position of the locknut or the original extension of the tie rod end casting as a guide are open to an error if the length of the casting is not identical to the original part.
This includes using the locknut, or using a mark/tape on the tie rod relative to the old tie rod end, and also 'counting the turns' you took to screw on or unscrew the tie rod end.
Only MY new method shown here will guarantee the original alignment will be maintained, even under conditions of slightly different replacement parts.
(b) failing to maintain the position (rotation) of the tie rod itself.
This is another plain flaw in any method which tries to simply screw the new part on, or measure from a mark or point on the tie rod itself. Since the rod can change its position relative to the car if it is screwed further in or further out, it must be held in its original position (rotationally) for any measurements made on it to have meaning or be of any use.
To overcome both these problems, I devised a new and simple way of marking the original alignment.
First I mark the rotation of the tie rod itself, by drawing a straight line along the top of the rod carefully, so that if it rotates slightly in either direction (say if the rod turns along with the locknut) it can be noticed and immediately restored.
Care must be taken when you are loosening the locknut on the tie rod that you notice if just the nut is turning, or if the whole nut and rod are turning relative to the tie rod end.
Here is a close up picture of the tie rod, and the line I put along the top (the most convenient place) so that I can tell if the rod has been accidentally rotated. I made this mark with a medium/heavy black (permanent) magic-marker.
When getting in and marking the shaft it is a good idea to take a close look at the threads so that you do not attempt to turn the locknut the wrong way.
To solve the second problem, that of mismatching of replacement parts (e.g. length of arm with thread inside), make a second set of marks:
(a) I mark the center of the old tie rod end ball joint itself with a dot. (You can skip this step if your tie rod end already has a centered grease nipple here. I will make all measurements from this point to a convenient point along the shaft. It is this point on the tie rod end that is critical to match with the new part.
(b)
I mark the tie rod itself with a line a fixed distance from the centerpoint of the ball joint on the tie rod end, because this ensures that the shaft (if it has not been rotated) will be the same distance away from the new ball joint.
The picture below illustrates the two markings. In my case, I made the distance exactly 9 inches, then drew the line around the tie rod shaft.
In conjunction with keeping the tie rod from rotating, this will maintain exactly the same alighnment that the car had before the replacement, and thats the best one can hope to do without paying for a toe-in alignment.
It should be noted that front-wheel drive cars often don't need caster alignments, because they can't be adjusted at all.
