Front Active-Aero Overhaul Procedure

The front active aero mechanism is a controversial feature on the 3000GT/GTO. At 50mph it drops to provide an enhanced venturi effect that provides more downforce, and then retreats back into the bodywork when speeds drop to 30mph. It is arguable whether it actively makes any difference to the handling of the car, but one thing is for sure, it's bloody annoying when it jams!

When it jams, a red warning light normally comes on in the cockpit and the rear active aero also refuses to operate. More than likely what has happened, is that the bushes that the front aero operates on have seized. They have probably never been lubricated during the cars lifetime, so if your aero hasn't seized yet, you can bet it will probably seize at some point in the future.

Despite the inherent complexity of some of the systems on this car, the front active aero mechanism is actually relatively simple. Rather than pay Mitsubishi's exhorbitant labour fees to do the work (£60 per hour + VAT anyone?), or even pay for a new front aero mechanism (yes, one guy was quoted £800!), I can guarantee that you WILL be able to do this yourself.

All you need is an hour of spare time, a trolley jack, a socket set, grease, emery cloth and possibly a set of maul grips.

Jack the car up using a trolley jack. You probably only need to jack one side up just so you have enough room to get to the underside of the active aero.

Remove the two front inspection covers. This will allow you to relocate the aero mounting points later:

There is a bar that goes along the width of the spoiler. It is connected to the aero mechanism by four bolts, two at each end (circled):

Remove these four bolts. The remaining bolts along the length of the bar simply attach it to the spoiler and do not need to be removed.

The way the spoiler works is that the mechanism at the front pushes the bar down and the whole thing just flexes on some rubber mounts towards the rear. To get at the spoiler mechanism, we also need to pull the front of the spoiler down, so it might be easier to do this if you remove the bolt on either side (circled):

With the bolts removed, the spoiler is now detached from the mechanism and should just flop down. There are some "ears" that stop it flopping all the way out, but you should be able to grab it and pull it further down and out. You may need to push it in a bit where it says "Active Aero" to bend the ears back so you can pull it all out. You can then get at the mechanism and marvel at it's simplicity!

You will quickly see the mounting hangers that the spoiler was attached to and also the bushes, which are more than likely seized (circled):

You can try and regrease them in situ, you may be lucky, or you may have to take the whole mechanism out, it depends how badly they are seized. On my car we were able to free the right hand one simply by undoing the two bolts (circled):

We were then able to wiggle the bush mounting and push the bush (circled) further along the bar to get to the corroded area. If it won't budge, spray on some WD40 or similar. If it's stuck really bad, you will probably have to remove it from the car:

Give it a good clean with some emery cloth:

Slap on some grease:

Now push the bush back into position. The bush mounting should rotate freely on the bar:

You can now attempt to free the left hand one, but there are 3 bolts to undo this time (circled). Note that the bottom bolt is going backwards into a captive nut:

On my car it was completely seized, so there was no option but to remove the mechanism. This means removing the motor drive nut (circled):

Now the whole thing should come away, and you can use some brute force (e.g. maul grips or a vice) to unseize that bush. Look how badly mine was corroded (circled):

Once again, use some emery cloth to clean up and lubricate with grease.

Re-assemble the whole thing back into the car. When tightening the motor drive nut, make sure you rotate the assembly so that the mounting hangars are in the correct position, e.g. if the spoiler seized when it was down, the hangers will need to be "down", but if the spoiler was up then obviously the hangers will need to be up. Rotate the assembly to the correct position before tightening the motor drive nut. If you get it wrong then the spoiler will be "down" when it's supposed to be "up" and vice-versa and you will have to loosen and re-adjust.

When you are ready to re-attach the spoiler bar via the four bolts (two at each end), you can use the inspection panels to insert a finger to locate the hanger mountings to aid insertion of the bolts.

Finally test it by turning on the ignition and flicking the active aero switch. Voila!