Sliding door sticking/grinding.

SOURCE: Sliding door is grinding as it opens/closes.

Ha ha.Not my usual type of answer but had the same problem about a month ago.At the bottom of the sliding door is usually 2 rollers.One at either end.They adjust up and down by using a screwdriver.The adjust screw is on the end or on the side of the door.You may only see a screwdriver hole.Adjust it down.Move the slider to the middle of the slide and lift it up and the bottom of the door should lift outwards toward you.This will allow the top of the door to come out of its slide area also.Once the door is out,check the rollers and you can easily see what may be wrong.Hope this is of help

SOURCE: sliding door on previa wont open or close properly

sound to like the door is out of alignment . It might have been closed hard on something while something was blocking the door. a mechanic need to adjust the level of the door or level the hinges and it should close properly.

SOURCE: sliding door is grinding as it opens. Can we lube

Chances are it is grinding because sand or other debris is in the track. Vacuum out the track and also lube it with a spray called WD40, available at any autozone store. If these steps do not solve your problem then you may have a bad part which will need to be replaced.

SOURCE: 2000 Toyota Sienna Sliding Door Latches Stick - Safety Hazard

clean and lubricate door sliding mechanism and locks with silicone spray lubricant, clean all door seals and jambs 

SOURCE: the sliding door on my 2004 toyota sienna won't close

Try this.....Find the latch on the door, stick your finger in the hole, lift up and pull the door handle at the same time, the inside latch mechanism should go up, then try the door again. It would be nice if that's all it was huh? Sometimes they stick when they get too cold. If this works for you....spray it with some WD-40 or graphite. Hope this worked for you. Cheaper than the 2000.00 motor!

Bryon