Tech: Fixing the Montero's Loose Mirrors

Note the odd angle on the 89's, and the poor 88's right mirror was MIA!

I am in my fifth year of Montero ownership, and in all those years, I have had one annoyance which, upon reflection, kept turning on me: those flimsy black rear-view mirrors needed constant adjustment. One mirror finally gave up the battle when I tried to tighten the stripped adjuster screw, and hung loosely like a pendant on my driver's door. I was finally forced to find a solution to this irritating problem.

I started by trying to diassemble the mirror. Not as easy as it sounds...

This was an ordeal from the beginning. After finally removing the adjusting screw (with the help of a hacksaw) I found that I couldn't remove the arm, which simply rattled around inside the mirror head. After unsuccessfully trying to force the arm out, I took a scraper, and forced it around the perimeter, where the frame meets the back of the mirror.

With careful tapping, you will eventually separate the frame from the back, and the whole assembly can be examined, without seven years of bad luck!

Forcing a scraper around the perimeter is tedious work...

...but it pays off, as the ring finally separates from the back...

... comes off the front, and the mirror lifts right off the head!

In its OEM form, the mirror is held in place by a metal backing plate, with a square dent in the middle of it, that is pressed against the arm's ball-end by the adjustor screw. In most cases, this backing plate rusts away, and nothing is left to press against the ball, resulting in a loosely mounted mirror.

In my case, after the mirror was dismantled I was faced with a rusty mess where the backing plate had once sat.  

Be prepared for what awaits inside the mirror: it may scare you!

The source of the problem: a backing plate that has rusted away.

Before proceeding with the fix, use some alcohol to clean up the inside.

The cleaned mirror-head, with the plastic spacer in place behind the ball.

This is where you need to put your creative genius to work. After cleaning the inside of the mirror, slide the plastic spacer back in place behind the ball, and put the mirror's arm back in position. Using a piece of thin steel (something which can be readily bent to the shape you want), cut a rectangular shape about 3" long, and put a small bend (around 5 degrees or so, for you geometry types) at the halfway point. At one end, slightly bend the corner so it will hook in the plastic slots in the mirror head.

After ensuring that your new backing plate will fit in the old slots without contacting the mirror after it is put back in place, mark where the new adjusting screw will go through the plate, and drill a hole in the metal.

Using a machine screw and nut (approximately 3/16 x 2"), tighten the backing plate against the ball, using the factory adjusting screw hole.

The screw is tightened,  drawing the backing plate against the ball.

Inserting the machine screw through the original hole, and into the plate.

The new backing plate, with a slight bend on one corner to anchor it.

Finally, put a little bit of liquid metal (or epoxy) between the machine nut and the backing plate, so future adjustment can be made to the adjusting screw without disassembly.

When tightening the machine screw make sure that the backing plate is is not too tight against the ball, to allow future adjustment of the mirror.

Loosen the two small screws to enable the mount to pivot.

Applying the epoxy to the mirror head and the trim ring (avoid the mirror!).

After cleaning the corresponding surfaces of both the mirror head and the trim ring, apply a bead of epoxy on the mating surfaces. Make sure that you do not allow excess glue to leak past the edges, or you may permanently glue the mirror to the plastic, making future repairs difficult. Put the mirror in place, ensuring that you have the correct side up (the mirror is not symmetrical), and press the ring over it.

Finally, loosen the two small screws on the base of the mount, to the point where it will pivot when pushed firmly.

With the rubber protector in place, screw the mirror back onto the door, and check the resistance provided by your new backing plate. If necessary, tighten or loosen the adjusting screw to achieve the necessary friction.

Although this seems to be an overly simple and basic project, mirrors that move by themselves can be at best frustrating, and at worst dangerous, when you need a quick check of your vehicle's immediate surroundings.