Corrado Moonroof Retrofit

Background:

My '92 Corrado VR6 sunroof had started to misbehave...a

common occurrence on the Corrado. The roof panel started to jam during closing

from the fully retracted position. The paint on the driver's side back

corner of the panel was beginning to scratch (only clear coat affected

thus far). I decided not to risk any further damage so I stopped retracting

the roof and I have used only the tilt function for the last 1.5 years.

This summer I decided to try to get it working again. Since I didn't really

know for sure which parts were the problem, replacing all the major moving

parts at once seemed the thing to do to be sure of a fix. Checking the

local dealer for replacement part prices, I was taken aback. To replace

just the 3 sliders on both sides of the track would cost over $300. Having

heard about Corrado's getting retrofit with sunroofs and even glass moonroofs

from other VW's, I decided it was time to give it a try. Found a '96 Passat

moonroof at GermanAutoHaus (formerly Bug World; www.bugworld.com) for $400

(without motor) plus $60 shipping. The Passat roof is said to be a close

fit to the Corrado's, so it seemed the best choice.

Thus begun the adventure of retrofitting my roof. Below

you will see a number of images I put together to assist others in planning/performing

similar retrofits.Feel free to contact

me with questions.

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Diagram 1: 1996 Passat Moonroof track parts exploded view.

Seems my visit to the dealer wasn't a waste of time. This diagram shows

all the major parts of the actual track, including the air deflector (14),

the drive motor (17), interior dome light housing/motor cover (23) and

the interior track trim piece (1). This trim piece is easy to pry off of

and push back on the track's inside edge. This piece was a cream color on the replacement roof so I reused the Corrado grey one instead. Since the diagram was provided

by the dealer, I assume all labeled parts are available as replacements.

Diagram 2: Sunroof & Moonroof mechanism components,

exploded view. Note that the Passat SUNroof is depicted in

the upper part of the diagram while the glass panel MOONroof

is shown below. I've added labels to the components I call sliders (because

that's what they do!). Note the part number 36 near the rear edge of the

moonroof track. This little part is a rubber bump stop for the headliner

panel and it seems to be only on the moonroof track; the Corrado's (and

Passat's) sunroof track doesn't have it. Again, I assume all the labeled

parts are replaceable... but not necessarily cheap. I had to replace the

drivers side rocker slider since my replacement roof's was damaged (rocker

lever pivot arm broke off)...it cost $65 USD. The front slider with its

air deflector arm attached (20) was $99...thankfully, mine didn't need

replacing. Also, the felt-covered glass panel sealing bead is not shown.

I decided to replace the worn out/torn one that came with my moonroof.

Cost was $50. It was fairly easy to pull the old one off the glass panel.

Replacing with the new bead was a NIGHTMARE! Easily the most difficult

part of the entire roof retrofit! The seal is made of a fairly inflexible

plastic, not rubber. It has a lower and upper edges that must be engaged

in upper ? lower grooves all the way around the glass panel. Took me

over 3 hours to get it in place, using various methods of force and lots

of soapy water to lubricate. My hands ached for three days! Proceed at

your own risk!

Fig. 1: Drivers side interior with headliner, rear roof

trim, B-pillar and A-pillar trim panels removed. B-Back

of car; F-

Front of car. Loosening the front part of the C-pillar panel also helps

in headliner removal. Note positions of B-pillar panel mounting screw holes.

The upper hole also mounts the coat hanger bracket. Middle screw is located

behind a small plastic cover plug in the B-pillar trim panel. Red line

shows approximate location of the "hidden" mount screw behind the lower

side panel. To reach this screw, it was necessary to partially remove the

lower side panel so that a small 90 degree ratcheting driver, with Phillips

head attached, could be used. This lower panel has one mount screw located

down near the door sill. Fold the rear seat down to expose two plastic

nuts that help loosen the panel further.

Fig. 2: Corrado's stock roof after headliner removed.

Some of the sunroof track mounting bolts are indicated as well as the passenger

side locating pin position. Bentley states to remove the roof panel prior

to removing the track.This is really only important if you want to re-use

or re-sell parts of the assemble later on, since you can only access the

components with the roof panel removed. To do this, it's necessary to tilt

the roof and slide the headliner back to gain access to the roof panel's

mounting bolts. Bentley shows a special tool for sliding the headliner

back. I think it could be easily done by pulling the inner liner down with

a large putty knife blade or similar flat tool until it's even with the

outer liner. Then push both liner parts rearward to disengage the liner's

frame from the main sunroof track. Since I removed the roof with it in

the closed position, I had to re-attach the motor drive and operate the

roof on my work bench to attain the tilt position and then proceed with

disassembly. If you're just going to discard the stock assembly, go ahead

and remove in the closed position with headliner in place. However, if

you're like me and have a "pack-rat" mentality, you will see a lot of the

track parts are fully interchangeable with the Passat roof, so they might

be handy one day.

Fig. 3: Close up of drivers side rear drain barbed fitting

and it's disconnected hose. Another track bolt is visible near the middle

of the image.

Fig. 4: Corrado's drivers side front drain barbed fitting

and its disconnected hose. The plastic drain fitting my on Passat roof

was damaged in shipping (despite warning them to protect these fragile

areas!). Since the dealer does not sell these separately, I cannibalized

the one off the Corrado track (identical). It's held on by plastic posts

(opposite side location shown in picture) welded through holes in the metal

track. Prying off the drain shears most of these posts cleanly off.

I was able to align the few remaining posts and used black silicone sealant

and some clamps to attach it to the new track. You might be able to save

more posts by grinding/drilling off the flattened head of the posts inside

the track groove from above.

Fig. 5: A damaged A-pillar panel can be easily repaired

with fiberglass cloth and a little polyester resin. The panel had cracked

nearly completely in half near the point where the mounting screw went through

the mount hole (shown above). The outside "leatherette" skin was undamaged,

the the panel was flimsy and in danger of further deterioration. I cut a

couple of layers of fiberglass cloth to shape and applied the resin with a

small brush, being careful not to put excessive amounts on and get it all

over the other side. After the 3 hour set time, the panel was stiffer & stronger

than the stock panel from the other side of the car. The resin, cloth &

catalyst can be purchased in a low cost kit at any good automotive supply

store with body repair supplies.

Fig. 6: Driverside Corrado sunroof mechanism in detail after

removal. The only real difference from the '96 Passat system I could detect

was the inner headliner tilt mechanism.

Fig.7: Passat roof track installed with sliding headliner

panel (shown pushed back). The track bolts right up to the stock roof holes.

Even though the locating pins (see Fig. 2 for the drivers side pin

location) are slightly longer on the Passat track, they still fit perfectly.

Perhaps they just provide a little bit more roof clearance for the glass

roof. Note that the headliner's frame is pushed back fully and is not even

visible here. This completely exposes the drivers side roof panel mechanism

(shown in the roof-closed position) with the mounting points for the panel

labeled. These mounts allow some adjustment in the roof panel's position.

When the panel is installed, just slightly tighten the bolts and check

the roof position. I initially pushed the panel as low as possible to ensure

clearance with the roof opening. Later, after a few test runs, I adjusted

it up a little to better fit the roof line. I had to replace the rocker

slider on this side since the original one was damaged. The new one is

black instead of chrome, but basically identical otherwise. The rocker

looks something like a type of beer-bottle opener.

Fig.8: View from outside, looking down at passenger side.

Here you can see the headliner's frame almost fully forward. The headliner

runs along a track in this frame. The metal clip engages in the rubber

grommet on the post when all the way forward (you'll feel it snap in) and

this holds the frame in place during normal operation. The only time you

need to push it back is to gain access to the roof panel's mounting bolts.

Note the original Passat chrome rocker at left (I could not tell the difference

with the new one or even the Corrado's rocker...interchangeable?).

Fig. 9: A close up of the passenger side rocker and the

cable slider in front of it. This is in the roof closed position. According

to Bentley, the cable slider pivots must be aligned with the notch in the

track before connecting the motor to the track. The rocker back end must

also be engaged in a notch in the track (not visible here...see Fig.

8 for detail). Also, the motor must be in the roof-closed position.

To obtain this, with the motor detached from the track, plug it into its

electrical connector and operate the roof switch. The closed position is

reached when the motor stops turning between the fully tilted (two turns

away) and fully retracted (nine turns away) positions. Note the position

of the rubber bumper on the left end of the rocker. This little O-ring

is what the CCA website garage section mentioned should be replaced on

the stock roof (using 3mm cloth-covered vacuum hose) to help prevent roof

failure. Although changing it eliminated the popping sound during roof

operation, I still ended up with roof jams & scratches less than 2

years afterwards. I don't believe it's the whole story...just one of many

wear items on these mechanisms.

Fig. 10: A close up of the drivers side rocker & cable

sliders in the roof closed position (the roof panel is actually installed

in this picture). Note the rocker end engaged in the rear track notch and

the cable slider's pivot positioned above the forward track notch. The

rocker wheel can also be seen here, but the rubber bumper O-ring is just

out of the picture to the left of the wheel.

Fig. 11: Finished moonroof in closed position while headliner

pushed back. Fit is very close all around, perhaps a little less snug than

stock. Note the light appearance of the outer sealing bead is due to reflection

from the camera flash…it is jet black in ambient light.

Fig. 12: The tilted position.

Fig. 13: Fully open. Note the inner trim piece used was the

original gray cloth one from the Corrado. Headliner is indicated pushed all

the way back. The air deflector was identical to the stock unit is shape and

position and is thus a prefect fit.

Results:

I am extremely pleased with the final results. The new roof looks/fits/operates

just as if it was a stock one. I took the headliner panel into a local

automotive upholstry place and selected a light charcoal grey cloth (it

came with a light cream colored cloth and plastic handle) to have it re-covered

and I removed the plastic handle and repainted it in "Soldier Grey" spray

paint. From the inside it really blends in perfectly. From the outside,

the roof panel is level & even all the way around the opening and the

felt sealing bead is also evenly aligned (although somewhat higher than

the roof opening & glass panel) all the way around.

Proceedure Description and Photos (C) COPYRIGHT Mike Dobbs, 2000