LX450 Window Falling Off Track

[OkieOverland]

The rear passenger window in my LX450 keeps falling out of the track. The wheel that raises and lowers the window is moving so far over that it comes out of the channel. I checked the other rear window and the wheel stays around 2-3” inside the track. I tried adjusting it but it continues to happen. Any ideas? The pics show how far over it goes before falling out and this happens every time I roll the window down.

 

[Kernal]

Something is off, loose, worn, or broken and the only way to tell IME is to remove the window lift motor and regulator (as a unit). Remove the door panel carefully, do not just yank or pull on it gorilla style, ensure all plastic rivets have been popped out of their holes using a plastic tool then pull the panel out a bit at the bottom and push upward. Unbolt the glass from the regulator but first tape the window glass up to the door so it doesn't fall (or remove it). For the front doors you have to position the glass such that you can get to the two 10mm bolts that attach it to the regulator. For the rear doors the plastic wheel just slides out of the glass channel rail. lThen remove the four 10mm bolts that mount the regulator to the door and remove it via the large opening. Will need to disconnect the motor from the wiring harness also.

Search you tube (FZJ80 or 80 series rear door motor replacement etc) there area few videos showing how to do all that

 

[Tim Herald]

Something is off, loose, worn, or broken and the only way to tell IME is to remove the window lift motor and regulator (as a unit). Remove the door panel carefully, do not just yank or pull on it gorilla style, ensure all plastic rivets have been popped out of their holes using a plastic tool then pull the panel out a bit at the bottom and push upward. Unbolt the glass from the regulator but first tape the window glass up to the door so it doesn't fall (or remove it). You have to position the glass such that you can get to the two 10mm bolts that attach it to the regulator. Then remove the four 10mm bolts that mount the regulator to the door and remove it via the large opening. Will need to disconnect the motor from the wiring harness also.

Search you tube (FZJ80 or 80 series rear door motor replacement etc) there area few videos showing how to do all that

When you say “ You have to position the glass such that you can get to the two 10mm bolts that attach it to the regulator” - what do the 2 10mm bolts attach to the regulator ? I have messed with mine a bit and was going to try to readjust the regulator a bit and have her the 4 that mount regulator to door - just wondering what you are saying those other two are for? It’s been a month since I was in there, so do t quite remember everything.

 

[getsthr]

On my 94, the window track on the back door glass is just pressed onto the bottom of the glass, unlike the fronts that are bolted on.
Mine slipped off too so I just slid the tracks on the glass to where it was centered for travel (same unused space on the up as well as when down). I took mine out and thoroughly cleaned the old grease out of the tracks and rollers, and regreased with some good grease {I used silicone, but manual calls for MP grease (white lithium is what GM uses)}. It seems as the grease gets old and thicker, the increased drag causes the track to slide on the window. I have also noticed that the increased speed/torque of the Window Rocket also accelerates this.

 

[jonheld]

This has been discussed 100s of times on this forum.
All 4 windows have rubber channel fillers at the bottom that fit into the piece that the regulator arm rides on.
After 30 years, the rubber dries out and the glass channel slides on the glass and the regulator arm slips out and the window falls.
Very common.
Front and rear window channel filler: 69971-90D00
Filler needs to be cut to length for the rear.

 

[Kernal]

Been awhile, confused front with rear. Fronts have two 10mm bolts that hold the bracket (glass channel) to the regulator, on rear door regulators IIRC the plastic wheel just slides in and out of the channel that is attached to the glass.

As mentioned above, all window glass is grabbed at the bottom by the U-shaped channel that holds onto the glass by "pinching" it, the filler acts like a cushion between the glass and the channel.

If the plastic wheel is coming out of the channel then something is out of whack, ie: glass channel coming loose from the glass, regulator coming loose from the door, motor coming loose from the regulator, regulator arm bent, plastic wheel worn/damaged, etc, etc. Just need to get in there to see what's not right.

IME the cause should become apparent as soon as you have the door panel removed ie: by running the window up and down while checking the various components for binding, wobble, looseness, etc.

 

[jonheld]

LOL. I had this happen about 3 weeks ago on my LX450. Right rear window fell when closing.
Removed the panel, peeled back some of the vapor barrier to gain access.
Moved the regulator arm to the horizontal position with the switch.
Had an extra pair of hands hold the window in the right place while I grabbed the window channel and pushed it back into position.
Done.

BTW, I see 2 different part numbers for the rubber filler, 69971-60020 for the front doors, and 69971-90D00 for front and rear. I'll hazard a guess that both will work for all 4 windows.
I replaced all 4 on mine not long after I got the truck, but I can't remember the part number I used.