Schwintek mechanisms are all under engineered, then poorly built with the cheapest, crummiest junk Chinese parts available, in China.
The slides and the support mechanisms and rollers are then, more often than not, installed incorrectly at the factory. Typically, the support rollers are not shimmed up enough to support the weight of the slide properly. As the slide operates over time, the weight of the slide not being supported chews up the motors, the tracks, and the connecting shafts.
There is NO QA whatsoever in the typical MH manufacturing plant. NO ONE ever inspects the slides and mechanics for proper operation. It is shipped as is to the typical RV dealer, who also does nothing other than operating it a couple of times to confirm it works at delivery.
You only get a one year warranty with an RV. It typically takes several dozen operation cycles of the slide to destroy it, so typically it might take 2-3 years for the slide to fail in typical use.
Out of warranty, a repair to a slide can be $3500 and up to $8000. Nice piece of service revenue work for the typical RV dealer. Another reason they aren't too quick to inspect them when new. The factory won't pay them nearly as much to fix a slide, as they can gouge you!
The whole RV industry, from the manufacturer, to the dealers, is one huge corrupt enterprise. It's the reason the industry is not growing. Millions of new people buy RV's every year, but millions also leave, fed up with being ripped off by unscrupulous manufacturers, dealers, and salespeople. We won't even talk about how many campgrounds now resemble Grapes of Wrath homeless camps.