DB9 Door Check Arm Replacement

It doesn't matter from what era, brand, or continent you're talking about.  If you're talking coupes, specifically coupe DOORS, we're talking big!  Even on a two-seat car, the doors seem to so long.  A four-seater, even longer!  This makes parking lots a dangerous place along with tight garage quarters, and on sports cars, high curbs.  I'm not sure if Aston Martin started their upward swinging doors to be different, or to solve a problem.  With the introduction of the DB9 Aston Martin took their long coupe doors and started opening them upward at a slight angle.  This is yet another beautiful and unique spin on a rather normal car operation.


With this new upward swing, Aston now had to compete with another law.  This being the law of gravity.  Normally, car doors open on a flat plane parallel to the ground.  When open, they usually stay open due to a door check strap.  This is a flat bar that has detents and some sort of spring force against them to hold the door in a few different positions.  This simple design is not enough to hold up against gravity.  This gas strut design is used in many other vehicle applications like on your engine bonnet and to hold up your rear liftgate.  When they wear-out they can be quite a nuisance.  And in some cases, not holding up a liftgate or a strut giving out at the wrong time can be dangerous!


We’ll give a brief outline here with pictures of how to replace the Aston Martin DB9 door check-arms (the V8 Vantage is very similar).  The job can be done with some patience, a few basic tools, and the help of a friend.


You will need:

  • T30 Torx bit or socket
  • Long narrow screwdriver or long straight pick 5” in length or longer
  • Trip pry tool
  • 22mm lug nut socket
  • Torque wrench
  • Jack with block or wood or hockey puck
  • 2 Jack stands


Park your DB9 in a space that can allow both doors to open all the way.  Loosen both front wheel lug nuts by one-half to three-quarters turn.  Yes, I am recommending you loosen your lugs BEFORE lifting your car.  This will use the vehicle’s weight to hold the wheel in place for you while you “break” the lug nuts loose.  This causes no harm to any components at all.  Use your jack and a protection pad like a hockey puck to lift the front of your car up and place jack stands under the chassis channels or the front lower control arms.  Remove the front wheel lug nuts and wheels.  Remove both front fender liners with the T30 socket.  There are a lot of fasteners here.  My picture shows the entire wheel arch liner removed. 

Once you’ve done a set or two of these, you may consider only removing the rear portion of the fender liner and pulling it forward over the brakes to gain access to the door check arms saving you the time of a dozen fasteners.  Locate the check arm in the door jamb area and inside the wheel arch cavity.  The best reference here is your new check arms.  Look at the ball-ends and see a small metal strap that is the shape of a “C” that clamps perpendicular to the gas strut.  Do not remove this from your new arms at any point – it is not necessary.  Locate these clips at each end on your existing check arms and use the screwdriver or pick to pry under these clips and slide them forward or backwards.  Just a few millimeters of movement is all you need.  But since you’ll be throwing these away with the old struts, feel free to pry them all the way off.  They are spring loaded so be careful of flying objects!  Use the trim tool to pop the ball-ends off of the ball heads. 

You will see that there is a channel that the check arm moves within.  Have your friend position and hold the door open to just the right point where the gas strut can come completely off of the ball head and be removed.  While your friend is in the perfect spot, grab your new gas strut and snap it right in place.  The metal “C” clips with naturally expand and then clasp over the ball head and you will be rewarded with an audible “click” when fully seated.  As always, reverse the removal process to assemble your car.  Hand tighten all your lug nuts as much as possible.  Ideally, gently lower your car until the tire kisses the ground and then at that point, torque the lug nuts to 100ftlbs.


All done!  Time to get into and out of your car

without a big door giving you an extra nudge.