Dreaded Sunroof Repair

One of the most common failures of the A2 platform is the sunroof. The sunroof on this generation of automobiles will tilt forward or lower itself and slide underneath the roof liner. It is quite an engineering feat to make this work properly. However, this does not come without its problems. The VW sunroof, especially the automatic powered units, will often jam when fully open and will scratch the top of the sunroof when one tries to slide it forward back into the closed position. Every Corrado owner has experienced this and it wasn't limited to the Corrado. B2 Passat owners experienced the same as the parts are indentical and interchangeable. The design was improved in the A3 generation.

I've heard many solutions to the jammed sunroof. Everything from replacing the O-ring, bending the tabs, andcleaning/greasing.

None of these solutions worked for me.

Getting to the sun roof required a lot of disassembly. One must remove the roofliner to get to the tract. The motor is located near the rearview mirror and has to be realigned when reassembled.

When I finally experienced the failure, I extracted the entire assembly and studied it carefully. I operated it by hand to observe how it worked. Several hours of disassembling and reassembling and I am convinced I've discovered why these fail.

Assuming all parts are aligned properly, there are two spring loaded sliders inside each side of the sunroof tract. This spring loaded slider will clamp the roof panel down while sliding forward and then release it once it reaches a tab on the tract. However, if that spring does not hold the panel down, the panel will attempt to tilt forward while still retracted into the roof. This causes the jam and ultimately the big scratch on the top.

The problem is the slider, there are small tabs which keep it in the rails. if these should fail, then the spring cannot keep the panel closed. Even a hairline fracture would compromise the part therefore releasing the spring clamp and the panel. Illustrated is the broken slider at top and new slider at the bottom.

I went looking for a replacement slider. However, every passat I examined in the salvage yard has the same fracture on one or both of the slider tabs.

There is a left and a right slider. I purchased a replacement for my fractured slider at the dealer. Cost was $65 each. I've replaced and reinstalled the tract back into the roof. I'll reassemble the interior when I get to that point.