1997 Eunos Roadster "Slow" Power Windows fix

by Phivos Hadjigeorgiou

The power windows of my Eunos have from the very first year been a great disappointment as they were slow in winding either up or down. Since the whine of the motors was quite alarming, I tried lubricating the window tracks and cable capstans a few times, using all sorts of lubricants including graphite grease (absolute crap as it blackens everything and slows the windows down even more) to no avail, as they could only temporarily alleviate the problem or worsen it (in the case of graphite grease).

Therefore, last weekend I decided to try and remove the glass from the regulator assembly in order to see whether there was anything obstructing the window guides. The procedure is simple and is performed as follows:

1. Remove the door pull by unscrewing the three screws (two at the bottom and one at the top of the door pull, concealed under a plastic cap, which needs to be removed using a flat screwdriver.
2. Slide the door lock knob to the "lock" position, unscrew the screw found underneath it with a Phillips head screwdriver and remove the door lock pod.
3. Remove the door panel by gently pulling on the edges of the vinyl-covered interior board until the clips snap off the door shell. Once you are done with the door clips, carefully lift the door panel upwards and away, releasing it from the door shell. For those with tweeters mounted on the door panels, do not yank the panel off, as it may sever the wire harness. Disconnect the tweeter wires.
4. Slowly and carefully remove the nylon that seals the door shell, being careful not to get any of the black gunk onto your hands or clothes. The thing never dries up, is impossible to clean off clothes, and once you get it onto your hands you must go through all sorts of improvised (and thus painful) cleaning procedures only short of chopping your hands off for convenience. Depending on the spec package of your Miata, you might have to remove some hardware to avoid ripping the nylon apart (i.e. the inside door lock mechanism, power door lock actuators). Once the nylon is removed, you should have access to the innards of the door shell, and regulator assembly.
5. Looking at the side of the door, where the lock mechanism that latches onto the car frame is (it is the same location that the tire pressure sticker is situated) you will see a small black plastic clip at the top that fastens the edge of the plastic window weather-stripping onto the door. Carefully pry that off using a flat screwdriver and pliers and then gently pull the weather-stripping up and away from the door, taking care not to break any of the remaining plastic clips that fasten it to the door.
6. Turn the ignition key to start, and wind the window down about 1/3 of the way, to reveal the three screws that attach the glass to the regulator assembly. Unscrew all three using a Phillips head screwdriver or a 10mm socket wrench in case they are too tight (you may need to move the window up or down to enable you to unscrew all three).
7. Wind the window down halfway, and unscrew both window stops (these are the white round capstans attached to the glass on either side of the forward power window track). You are now ready to remove the door glass from the door.
8. Whilst holding on to the glass firmly (remember you are about to remove the thing don't let go of it otherwise it might fall out of the window tracks and break) tilt it a bit to the back (pull the rear side of the glass up and rearwards whilst winding the window up to remove its forward edge from the front window frame) and carefully wind it up all the way and lift it out of the door shell.
9. Have a good look at the tracks to see if there are any visible obstructions in the tracks (in my case there were a couple of mashed leaves and the remains of a rather unfortunate lizard (!!!) caught in there). If you cannot see anything, then try and feel the tracks for any obstructions using your fingers. Once the tracks are cleaned, you can apply a bit of lithium grease to the tracks and cable capstans, a process that is much easier now that the glass is gone.
10. Check that the rear white Teflon guide (this guide goes into the rear window track) attached to the window is not damaged, broken or disfigured. In my case (on both doors) the rear guide was disfigured (i.e. it was warped and looked more like a crooked donut than a flat disc as I am sure it looked like when installed at the factory 6 years ago). There are two choices available to repair the problem. The first one entails going down to your local Mazda dealership and making them richer by buying two new rear window guides and replacing them (a rather cumbersome procedure) or reuse the old ones after, of course, performing a bit of "cosmetic surgery" to them. Replacing the window guide is rather cumbersome and entails taking a risk of breaking the glass if the right precautions are not taken.
11. For those who never chose the easy way out in their lives: First, the glass around the window guide where you will be working, should be covered with some army tape to prevent it from being scratched in case your pliers slide off the rear washer whilst holding it fast. Next, the rear washer should be sprayed with some penetrating oil to loosen the bolt, which will almost certainly have seized from dirt and exposure to the elements. After allowing the penetrating oil to take effect, use safety pin removal pliers (insert the two tips of the pliers into the holes on the washer) to hold the washer onto the back of the window guide, whilst using a star wrench (T40) to unscrew the bolt. Make sure your movements are slow and precise as any mistake could cause the glass to crack or shatter. Once the bolt has been removed, replace the window guide and reassemble in reverse order. Ensure that the bolt is not overtightened as this will most certainly break the glass.
12. The simplest, cheapest and most effective solution in my opinion is the one I have chosen to adopt, which was to perform some "cosmetic surgery" to my disfigured window guides. This will work ONLY if your window guides are not cracked or broken. Looking at the top of the window guide, you will see a narrow raised ring on either side, which I presume is for eliminating any play in the window guide/track assembly. Since my window guide was not so disfigured or cracked in any way to render it unusable, I decided to "carve" the raised ring off both faces of the guide, thereby smoothing the surface and making the guide thinner, to enable it to move with less friction in the window track. This was done using a sharp blade, and there was no need to remove the window guide from the glass.
13. After the fix is performed, the window is reassembled in the reverse way to disassembly. In order to make you windows wind up and down faster, once the glass is mounted onto the regulator assembly, loosen the bolts (not too much, just enough to allow the assembly to move) that hold the regulator assembly onto the door shell as well as the bolts that hold the rear window track onto the door shell. Lower the window halfway down, and tighten the bolts of the assemblies that you loosened before in the place where the window pushes them after ensuring that the window is running straight in its guides. I have tried tightening the bolts in different positions, including the position where the window was wound fully up, but found that adjusting the regulator in the middle position allows the glass to move more freely.
14. Finally, replace the door shell nylon, the door panel and door pull in reverse order to disassembly.
15. Repeat the procedure for the passenger side window. It is worth mentioning that the passenger side window guide was warped exactly like the driver side.

It has now been a week since I have performed the repair, and the windows are moving far faster than before, free from the motor "whine" that I was experiencing before. I guess that the rear window guide gets warped by a combination of heat, stress and exposure to the elements and should be checked on all M1 Miatas, Eunos Roadsters or MX-5's that have slow winding power windows. Who knows, this could save you a bunch of money and it is not so difficult to perform. Needless to say, readers use the above information at own risk; you performing the fix denotes that YOU and only YOU accept the risk and responsibility for any damage/ injury / destruction to you, your car or anyone else around you, be they dead or alive or half-dead.

Phivos Hadjigeorgiou
Nicosia, CYPRUS

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27 July, 2003