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caji

94 Es300 Back Door Window

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Hi Guys,

The back door window of my 94 Es300 just suddenly drop down. It looks like it has cable to open and close the window. Is the motor shut? Right now when I activate the switch,the travel of the cable is only 2 to 3 inches. What makes the window to travel upward? Is it the cable? I could open the other door and see how it works, but I won't do that until I hear from you guys. I am beginning to hate my Lexus. I just finished repairing the instrument cluster of this one. Hope to hear from you guys.

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You'll have to pull the inside door panel to find out the fix required. It sounds like the cable has snapped or is stripped on its gear at the motor. I'd check it out first, and if parts are needed, try tracking down a replacement cable assembly from a wrecking yard for the same generation ES or Camry, as the parts are most likely the same. For someone with a little wrenching ability it should be an easy, if time consuming fix. Good Luck!

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You'll have to pull the inside door panel to find out the fix required. It sounds like the cable has snapped or is stripped on its gear at the motor. I'd check it out first, and if parts are needed, try tracking down a replacement cable assembly from a wrecking yard for the same generation ES or Camry, as the parts are most likely the same. For someone with a little wrenching ability it should be an easy, if time consuming fix. Good Luck!

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Thanks for replying. The cable that connects to the plastic on the regulator broke, so the cable is screwed up. I ordered the window regulator with motor on Ebay for $62.00 including shipping. My problem is the procedure on removing the existing window regulator. I know I have to remove the glass before I can remove the regulator. I can see that I have access to all the bolts to the glass except one, which is behind the rail. I can remove this using a wrench. Am I doing the right thing. Have you done this before on this particular model? I don't have service manual on this car.

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i never did the back window. i did the drivers side. I would say not to remove the window. me and my friend tried to and we kind of messed up the rubber padding that kind of seals the window so water doesn't seep through. i would say when you have it just remove the glass from the regulator and just hold the glass up until you can put the new regulator in and then just have the glass situated on it. just take pics if need be so you can put everything back the right way no problem. hope this helps

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i never did the back window. i did the drivers side. I would say not to remove the window. me and my friend tried to and we kind of messed up the rubber padding that kind of seals the window so water doesn't seep through. i would say when you have it just remove the glass from the regulator and just hold the glass up until you can put the new regulator in and then just have the glass situated on it. just take pics if need be so you can put everything back the right way no problem. hope this helps

I don't think you could remove the regulator without removing the glass. I will figure it out when I receive my regulator. Thanks anyway for your help.

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Typically to remove the glass you will have to lower it in the door, until the bolts/plastic plugs that secure the glass to its bottom rail (usually one at the front and one at the rear), line up with openings cut in the door itself. Most of the time those openings are just about at the bottom of the glasses travel. Then you can get a socket on an extension in to the nuts/bolts/plug. Once they're out you can tilt the glass down at the back, up at the front, and slide it out of its front and rear tracks, and once free slide it up and out of the door towards the outside of the car. Assembly is just the reverse.

It really isn't difficult at all, just rather intimidating the first time you do it. Personally I've done 100 or so such jobs over the years, from 1930's antiques to new models. The only other setup I've seen was on a Volkswagen Rabbit years ago where the glass was glued into a U-shaped channel along its bottom edge. (German engineering.)Good Luck!

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Typically to remove the glass you will have to lower it in the door, until the bolts/plastic plugs that secure the glass to its bottom rail (usually one at the front and one at the rear), line up with openings cut in the door itself. Most of the time those openings are just about at the bottom of the glasses travel. Then you can get a socket on an extension in to the nuts/bolts/plug. Once they're out you can tilt the glass down at the back, up at the front, and slide it out of its front and rear tracks, and once free slide it up and out of the door towards the outside of the car. Assembly is just the reverse.

It really isn't difficult at all, just rather intimidating the first time you do it. Personally I've done 100 or so such jobs over the years, from 1930's antiques to new models. The only other setup I've seen was on a Volkswagen Rabbit years ago where the glass was glued into a U-shaped channel along its bottom edge. (German engineering.)Good Luck!

Thanks again for replying. Unfortunately, I check my ebay and the guy who is sending the regulator will be back 14th of this month. That means I will be receiving this on the 20th of the month. I don't think this guy will get a good feedback from me. Right now my wife is using the car with the window up supported by a piece of wood. I will update this thread when I finish installing the window regulator. Thanks again and have a nice day.

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I finally got my power window installed. Here's the installation procedure for people who wants to do it themselves:

1. Remove door panel.

2. Remove motor (disconnect wiring)

3. Remove motor bracket (disconnect wiring to door lock)

4. Support window with a piece of wood. Now you can remove the two bolts connected to the regulator and then remove the remaining two bolts with plastic inserts.

5. Remove the wood support and let the glass window all the way down. Remove the stopper and the two brackets with felt that hold the window in place. The glass window can now be removed by tilting to the lock side and pulling it up clearing any obstructions.

6. Remove the window regulator (four bolts)

7. Install the new window regulator with motor. Remember to put some grease on all the tracks.

8. Install motor bracket.

9. Connect power to motor. Test movement of the regulator and put it all the way down.

10. Now put the glass window back all the way down.

11. Install two brackets with felt back.

12. Install stopper, don't tighten it yet.

13. Move the regulator up or down to align the glass window holes for the bolts.

14. Once the four bolts are installed, try the operation of the window.

15. Adjust window through the stopper.

16. If everything is properly aligned, tighten all the bolts.

17. Replace the panel.

That's all it is to it.

Cost of regulator with motor on Ebay---$62.00

Dealer cost with installation----------$800.00 plus

Gratification in doing it yourself------Priceless

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Excellent! It's so nice to see other Lexus owner who are not helpless.

Our 1992 ES-300 driver's side rear door window developed a failure mode. On disassembly, I found the end of one of the two cables had kinked and bent inside the motor-driven spool case. You already know the dealer wants more to repair that than is reasonable. Lexus assumes their dealership mechanics are too helpless to replace a cable which might be sold for $15-$20, so they instruct them to replace the entire assembly for $-hundreds.

I used two small pliers, one a 4-inch ViceGrip, to retwist and straighten that bent cable's end. I didn't trust that end section to stay straight within the spool-case track, so I cut an inner groove into the plastic spool for about that kinked-section's length, which was about one inch. Then I cut a new exit track for that cable about 1.5-inch further around the spool's diameter. When I fitted the cable in that new track, it seems stable, but just to be certain, I applied enough heat with a soldering iron tip to melt the plastic spool side tightly against that kinked cable section. Warning: If you do this, that plastic REALLY stinks when heated. The smell will quickly disappear, but while heating it, I suggest not having your nose right over the work.

The shortened effective cable length is still long enough to enable full up and down window travel. Parts cost for this repair = $0.00 Dealer estimate $800.00 Sorry to report that since I've never worked on one of these before, it took me about 2 hours. If I did the same on another, my time to completion would be significantly faster.

Ok, lots of you Lexus owners have not the foggiest idea of how your power windows operate. Generally, they use one of the following two design strategies.

Two cables attached to one motor-driven reel:

Imagine a fixed-diameter reel on which a single wrap of cable is wound. For every angular rotation of that fixed-diameter reel, a circumference-corresponding fixed cable length reels out. Now instead of having only one cable wound around that fixed-diameter reel, you have a second cable wound on from the opposite direction. As you rotate that reel in either direction, the same length of cable which one cable reels out exactly matches cable length the other cable reels onto the spool reel. Very simple, very elegant, very effective. Now, just run those cables through some pulleys and cable sheaths so they attach to the window support bar. One attaches and pulls from the top side, the other attaches and pulls from the bottom side. So as you spin that motor-driven spool reel, the window is pulled either up or down by one of those two cables, which the other cable lets out exactly equal cable length. Pretty cute, right? Ok, we don't want any cable slop to cause wrapping problems around the spool, so add two coil springs, one for each cable to maintain cable tension at the cable stops. That should take care of any cable slop, right? Well, those little springs do keep cable slop to a trouble-free minimum so long as the lubrication inside the cable sheaths is reasonably low. But if friction resists cable pulling more than the spring's tension, reversing direction can leave enough cable slop to cause cable winding bunches and lockups.

Problems arise when that XX-teen year old cable sheath lubrication grease evaporates out so much of its most volatile components that the remaining grease becomes VERY STIFF. Trust me, this will also happen to your cable sheath's lubrication over long periods. I'm guessing that in the hottest geographical locations, this grease stiffening happens faster due to heat-driven evaporation. So force some penetrating oil like PB Blaster from one end of those cable sheaths to their other end. This may take a few minutes to trickle a drop at a time along those cables while sliding the cable sheath back and forth on the cable. I held one end higher than the other to gain gravity assist helping this cable friction reduction work. When those cable sheaths slide with so little friction that you can barely feel their resistance, you're ready to reassemble it for perhaps another 10 years of grease drying. We can only speculate how long it will take to become stiff again. If you fail to eliminate high cable sheath friction relative to the cables, your springs won't prevent cable bunching and possible cable reel tangles. Why Lexus didn't use a totally-non-volatile grease within those cable sheaths is a mystery to me. I think some silicone-based greases are non-volatile at under 150 degrees F. In my opinion, that wrongly-specified cable sheath grease has caused thousands of power window failures in what would otherwise have been a much more trouble-free system.

Ok, back to the design. The electric motor drives the plastic spool or reel with a worm drive gear. That is a very elegant solution for the following reason. Worm drive friction is low enough to pass at least 50% of the driving force to the driven load. But that same friction prevents the driven load side from back-driving the motor. So the motor moves the cable reel to what ever window height you prefer, then effectively locks the window in that position by way of the worm drive's one-way limited power delivery characteristic. You've got to admit, that's pretty good design.

The other popular power window design uses the classic parallelogram scissors lift configuration. One end of the "X" pattern crossing bars forming the scissors is locked into a horizontal sliding track, where it passively slides. The driving end of a bar is pushed and pulled by an electric motor driven linkage. Several configurations have been used over the decades to drive them. Unlike linear-force curve dual-cable reel type driving systems, scissors lifts develop much higher lifting force as the lift approaches completion because that force tracks toward the sine wave top. That progressively higher closing force helps drive windows more tightly against rain shield gaskets. Whereas the cable-type systems apply the same force through their entire travel. Both can work well. Both can develop problems.

A very common power window problem is excessive friction. I already explained how cable sheath grease drying and stiffening degrades operational performance and can ultimately cause cable winding bunching around spools. The other common friction problems are within tracks. Windows slide in factory-lubricated tracks. You would be foolish to think that factory-lubrication will never need replacement. Rain, wind, blowing dust all work into window track slides, causing migration of that factory-lubrication. A popular but very questionable solution is applying spray silicone lubrication to window slides. Non-spray silicone or graphite-based lubrications are much safer. Why do I say that? Because spray-can silicone is like cancer to any repainting work that door may later need. I know of one person who applied spray silicone to some parts of his car before a paint shop repainted it. He failed to warn them. They charged him hundreds of dollars for the repaint work. A $15 tube of silicone-based solid grease may serve your needs for decades. Apply inside tracks with a Q-Tip or equivalent.

Another comment about operational friction levels many times higher than factory designer's expectations. When electric window operating systems are well lubricated, those tiny electric motors (Mitusbitshi?) rarely fail. But as we progressively overload them with more and more friction, they do fail. Not only do they fail, but as those electric motors are working many times harder than should be required, they present much higher switched electric loads. So their control switches, relays in some systems, and fuses fail from overloading all caused by excessive friction. Want to hear some real comedy? Some people discover that their window motor power limiting fuse failed and just pop in another fuse rather than correct the underlying friction problem! "I laugh lest I might not cry."

Sorry for this post's length, but I'm providing information too few understand to protect their auto investments economically. I genuinely hope these comments will enhance some others understanding of how these systems work and how you may economically keep yours working.

John

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