Outside Mirrors

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Problems with Parts

There are two problem parts in the mirror assembly: the Mirror Glass and Pivot Pins.

Door Mirror Glass: A100U0205F (Works both sides)
Pivot Pin - Door Mirror Glass A100U6056S (Works both sides)

The problems with loose Mirror Glass are caused by its fixing and adjustment mechanism. There are several points of failure. The Mirror Glass consists of several parts glued together: the mirror, the heating element and a plastic backing plate. The backing plate snaps into a “spider” (a cross shaped universal joint that is gray in the pictures) using the elasticity of the backing plate’s plastic composition to hold on to the spider. This is what serves to hold the Mirror Glass to the car. Adjusting the mirror actually utilizes some very elegant engineering. The two Pivot Pins run in and out via engagement to electrically driven, rotating, threaded gears.

The failure points of the Mirror Glass are related to molded plastic protrusions that holds the spider. If one of these protrusions breaks, the Mirror Glass can “float” either up and down or side to side. See pictures below.

The Pivot Pin is a very complex one piece molding. On one end the Pivot Pin has very small teeth that are cantilevered off from the main body. It is theses small teeth that are forced into engagement with the rotating threaded gears, of the drive mechanism, by the natural elasticity of the plastic. Note that the cantilevering also acts to protect the teeth; it allows them to slip rather than break when driven all the way inward to the Pivot Pin’s limit of motion. On the other end of the Pivot Pin there is a ball joint with ears. This ball with ears snaps into the Mirror Glass, the ball providing articulation and the ears keeping the Pivot Pin from spinning. Therefore for the Pivot Pin to cause the mirror to move the ball must be fully seated in the socket of the Mirror Glass’ backing plate, the ears must be engaged in the slots that are molded into this socket and the cantilevered teeth must be engaged into the threads of the rotating gear.

There are two failure points on the Pivot Pins. The cantilevered tooth can and does break off. The ears on the ball are fragile and can also break.

As can be seen from the above write-up fitting the Mirror Glass to the car is somewhat difficult. It must connect to three separate pieces all at about the same time. The level of force needed to seat the Mirror Glass to the spider and the Pivot Pins to the rotating nuts is significantly different. The trick that I use is to:

1. Fix the Pivot Pins to the Mirror Glass. A dollop of silicon grease may help the function of the mirror adjustment.

2. Connect the heater element wiring

3. Carefully align the Pivot Pins and push them into their respective rotating threaded gears. Do not push them all the way in, leave plenty of play for the necessary adjustments of the next step.

4. Move the Mirror Glass so it is just starting to engage the spider. Doing this will further engage the Pivot Pins into the threads.

5. Give the Mirror Glass a good sharp whack with my hand to fully engage the spider

Pivot Pin.jpg

Pivot Pin, plastic, door mirror (A100U6056S). Although it is difficult to see, this piece is also broken. The whole thing is only about an inch (25 mm) long. Two are required per mirror.

Mirror Back.jpg

Mirror Glass, heated, convex The passenger side mirror from a left hand drive (federal) car.

Mirror Back Detail.jpg

Note the broken ear that connects to the spider. Also note the two pedestals that have hemispherical indentations and a slot. These pedestals hold the Pivot Pins.

Mirror Body Internal.jpg

Problem with Fitment

A separate problem with the mirrors concerns the safety fold back feature. A symptom of this is that one of the mirrors seems to be positioned differently from the other and one mirror cannot be adjusted to provide a useful view. The mirror housing (my terminology, the nice red part in the associated pictures that holds the adjusting mechanism and Mirror Glass) is held to the car by two springs. Each mirror is positioned by two slotted tabs (front and back) that fit into the black plastic mirror mount (again my terminology). If the mirror housing hits something solid, like a pedestrian, it cams out of mirror mount. Hopefully; this prevents limits damage to the pedestrian and prevents breakage of the mirror.

If the mirror housing has ever been displaced from of its mount, it is possible that it did not get replaced correctly. Check this by pealing back the flexible bellows like cover and having a good look-see. If the mirror’s positioning tabs are not properly engaged it is time to use the strong arm method of repositioning them. Ensure that the door is firmly closed! Pull the mirror housing away from the car, out of engagement with the mirror mount, then gently allow it to reseat, being careful to align the tabs to the mirror mount. Warning, you will be pulling against heavy spring pressure. A good firm grasp of the mirror is necessary. During this procedure it is especially wise not to be wearing items that can scratch the paint (e.g., rings, metal belt buckles, …).

General Warnings and Cautions

I’m no mechanic. I will not be held responsible for death, injury mechanical damage and etc. If you need a real mechanic to help you fix your Lotus I suggest you go find one.

Roll the windows down. Working near expensive, possibly sharp glass never seems like a good idea.

Take off your jewelry! Not only is it a good general safety practice, you will be working near glass. See the previous line.

Don’t wear anything that will scratch the paint. See the previous two lines.

Use your head. With the engine off, put the car in gear and set the parking brake.

Good Luck

--DeanG 00:34, 14 November 2008 (UTC)