Firstly, you should read the instruction book of RC cars because it would tell you the length of push rods. If there is no information about this on instruction book, two methods can be adopted, one is measuring length by calipers and the other is estimating by eyes.
Secondly, daubing lubricating grease on push rods, which is an important step but often neglected by people. By this way, it is easy for you to adjust the length of push rods in future and it can’t be prized up easily by strong force.
Thirdly, making ball link into push rod a little. To ensure the ball link is aligned with the push rod and rotate into push rod smoothly.
Fourthly, fixing the middle part of push rod by spanner. We’d better use special ball link tools, if not, sharp-nose pliers is tol-lol choice. We then carefully screw about two or three circles at one end and screw other end. Repeat the process until it is fixed.
Fifthly. Measuring the accurate length of push rods by vernier caliper.
Sixthly. As usual, ball link can be pressed by hands, however, you can use slotted point screwdriver to achieve difficult processes.