Common sense and assembly manuals say that both shocks on each end of
a car must be the same length. But even digital calipers can give an inaccurate
measurement because they measure the length of the shock from end to end,
and the most accurate way to compare lengths is to measure from the center
of the upper and lower shock-mounting points. Note that the length shown
on the tool's measurement indicator is taken from the center of the mounts
and is not the overall length, so it may not be the same as the measurement
listed on your favorite team driver's setup sheet.
STEP 1. Mount a pair of shocks on the tool.
STEP 2. Fully extend the shocks.
STEP 3. Look at the gauge pointer; if it's centered, your shocks
are the same length.
STEP 4. If one shock is shorter than the other, unscrew its eyeletuntil
both shocks are the same length.