2006 Lucerne CXS - No Lumbar Support

[pcmos]

Let's tackle the next problem with my ridiculous Buick... Two days after I bought the car I adjusted the lumbar support in the passenger seat, heard a loud "twang" and after that lumbar was gone and the seat back collapsed. I took the back off the seat and could see parts flopping around. I took the back off the driver seat and rebuilt the passenger seat to match. When I press the lumbar button the motor hums but nothing happens, the cable doesn't move. About three days later, I adjusted the lumbar on the driver seat and guess what?? "TWANG" and so for most of the time I've owned this stupid car, I've had zero lumbar support. Anyone else experience this miserable problem, if so, what was the resolution?

 

[Weatherby]

SAME problem, but only on drivers side, just living with it so far. Will take seat apart soon.

 

[pcmos]

I took the back of the passenger side after it happened and it looks like there is a motor with a cable reel of some sort. It feels to me like the cable is disengaged from the reel. My guess is some piece of plastic inside that motor head has snapped and let the cable go slack. Unfortunately those things are really tricky to repair and nearly impossible to source. When you pull the seat back off BTW please be careful. The leather/cardboard back is stapled to a plastic frame. When I pulled mine off I ended up ripping the leather and cardboard back right off of the plastic frame... I had to spend hours pulling the old staples out and using my staple gun to staple the stupid thing back together. There are some little clips that you have to release one at a time and very carefully to avoid the same hassle. I'm usually pretty good at getting those sorts of things apart without doing damage but that seat back is really flimsy.

 

[pcmos]

I took the lumbar adjustment motors apart and found the same failure in all four gear boxes. Please see the attached picture. The plastic gears are literally ground up into tiny little chunks. I counted the chunks and found 42 teeth. I know there must have been three gears, so that means that they have 14 teeth each. The plastic hub is also snapped in half but may be able to be repaired. I'll have to guess at all of the other pertinent specifications. Hopefully I can find a source for replacement gears but I don't hold out much hope. Nobody in their right mind would mass produce a nylon gear so frail and subject it to so much load. Buick went out of their way to make something this crummy.

 

[polarzak]

I don't think I have ever adjusted the lumbar support in my Lucerne since buying it new. After reading this thread this morning and went out on an errand and thought..geez, I wonder if mine works. Nope...just a whirrzzz. Glad it didn't go into some uncomfortable position and THEN snap.
It can stay that way as far as I am concerned, but in case I get bored silly someday, how hard is it to get the back of the driver seat off? Probably could figure it out easily enough, but a heads up would be nice.
Thanks.

 

[pcmos]

I'll grab a picture of the back the next time I have it off. There are just a few plastic and metal clips on that rigid part that backs up the map pocket. The trick is to pull the bottom out first. Just pull straight out on the very bottom (it's tight) of that panel and tip it outward. The top edge hooks into the upper part of the seat frame. The problem is that the leather is stapled to a piece of cheap cardboard which in turn is stapled to the plastic panel frame. If you pull on the leather or cardboard it just rips right off of the plastic frame and you need to use a staple gun to reattach it. After you get the panel off, the actuator motors are pop rivetted to the adjuster frame. I just took a drill and drilled out the rivet. I left the driver side more or less intact because otherwise it will take me forever to figure out the linkages again. I reccomend doing one at a time. I'm going to stop by the dealer today and see if those motors are even available. If not I'll need to see if the used LeSabre seats I bought might have some donor gears someplace. If that fails I'll have to source similar gears from McMaster Carr or something. I WANT MY LUMBAR BACK, lol. What a rotten pain in the you know what, ughh.

 

[pcmos]

PS... they used some sort of petroleum grease in that gearbox and I suspect it attacked the nylon gears chemically. The odor from that gearbox made me sick to my stomach after I opened it. I'm not usually bothered by smells or chemicals but something about the chemical reaction happening inside that gearbox really had me running for fresh air. I put all those chunks in three ziplock bags and left it outside on the porch. The smell was nauseating. Someone didn't do their homework at GM because by definition I think that was the WRONG grease to spec.

 

[polarzak]

Thanks pcmos. Man, with all your experience with your vehicle, you are going to be, if not already are, the Lucerne expert. Thanks and again good luck with yours.