My chair squeaks on my model C2. How do I repair?

I have not done this myself, but I found some users of the Whill C2 on reddit, who have various squeaking problems too.

It might not be the same squeak as yours, since they say the squeak is in teh quick release mechanism.

In this thread (https://old.reddit.com/r/wheelchairs/com...) user BS-75_actual says the quick release mechanism needs lubricating. They also say that if your controller assembly has any loose screws, it will cause a rattle. And they found another squeak from the lever accidentally getting released when the user leaned over. And yet another squeak was caused by a nylon washer on teh spindle getting worn out, so if it might need replacing.

On this thread (https://old.reddit.com/r/wheelchairs/com...) the user says a tech walked them through several steps to find squeaks

First thing I did was on my own. I folded a small piece of some fine grit sandpaper in half so that there was grit on both sides. I put it between the fender and shroud (drive unit) underneath the suspension spring and sanded the plastic so that there wasn’t anything to rub that wasn’t perfectly smooth. It stopped a small popping noise that happened when the fender was bumped.

The tech had me remove the tire and loosen and retighten the fender on the side that I heard the creak the most. One of the screws wasn’t as tight as the others. He thought it might re-seat the plastic if a rub was causing it.

He also had me lube the brass bushings at the center of the A-arms. If you flip the drive unit over, there are two large arms that go from the center out to the wheels. These are the suspension arms. In the center are two large bolts with brass bushings. Lube between these bushings.

You might want search reddit's r/wheelchairs to see if there's anything I missed.