Bob Bidonde's method works by measuring the spring length (often 1") and compressing it 1/4" by watching the tie rod or drag link plug threads depth. This usually allows for the cotter pin to insert easily. A large screw driver can be used on the ends with the teflon / plastic seats.
I had my drag link off yesterday, so I investigated this.
My spring length is 0.92" long, so 25% of that is 0.23".
The screw plug has 20 threads per inch, so 1 full turn of the screw plug moves it in (compresses the spring) 0.05".
So to compress the spring 0.23", you need to turn the screw plug 4.6 turns.
I ran the screw plug in with my fingers and a small screw driver until the plug just touched the spring and got all the slack out of the end. Then I screwed it in to where the slot lined up with the holes for the cotter pin. From there it was easy to count 4-1/2 turns of the plug and then slip the cotter pin in.
I always do the above twice. In other words, I screw the plug in tight, to compress all the slop out of the end, the spring, the cups -- get everything seated. Then I loosen the plug fully and repeat. That way, when I am just touching the spring and beginning to compress it, I know there is no slack in there, and I count 4-1/2 turns from there.
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