Rear spoiler issues
 

Guys,

I am preparing my 1991 C2 Tiptronic for sale and of course this is when my rear spoiler starts acting up.

Right now manual control does not work. Previously, it worked intermittantly. Rear spoiler goes up part way. Spoiler light sometime turns on. Sometimes problem goes completely away.

Seems electrical to me, and not mechanical. We start with limit switches but anyone know if this obviously points to something?

Right now it is stuck half-way, semi-erect, manual control does not and this has lasted for more than 4 hours and need to call the 911 doctor.

Looking at other posts, first thing I did was remove the spoiler mechanism cover. Limit switches seem fine and make that "click" sound when closed. Since my spoiler is half-way up both switches are in the open position. Then I disconnected the harness to the switches and checked for continuity. Both switches function fine electrically. They close properly and continuity check passes. I don't think I have bad switches. On to the next thing. BTW, my spoiler is stuck in the half-way position in these photos.

Me thinks its time to go inspect the controller next which is supposed to be under the Glove Box on a 1991 model.

This seems like the relevant module diagnosis thread.
https://rennlist.com/forums/964-foru...ml#post3704925

Hello Ricardo,

Have you checked the fuse? #37 - 15amp
The gearing/flex cable could be failing and the mechanism bound up blowing the fuse.

Mojorizing,

Thank you. I should have checked fuse #37 first. I pulled it and it looks fine and passes the check with my little Bussmann fuse tester.

Might be worth checking the motor runs with the spoiler flex drive disconnected. You could also check the flex drive gearbox is not seizing up too.
:cool:

If you turn the drive cable by hand does the spoiler go up and down easily?

Does the spoiler deploy/retract in auto, but not working in manual?

Thank you for the suggestions guys. I removed the drive cable from the motor (see instructions below). Then put the car in the key on position and when I used the manual control I could hear the motor spin in both directions. I then had my wife help me and confirmed the manual control works fine and I can see the square drive drive spin in both directions with the manual control.

That means I have a failed spoiler side gear drive mechanism.

part number: 964-624-121-00 that's a $300 part at sunset.com

anybody got a used one?

EDIT: The gear mechanism is a repairable part! ToreB has a guide on his site. ToreB is the man!!!! I will give this a try and report back.
https://www.bergvillfx.com/spoilerrepair/

I am getting the car detailed tomorrow so I will re-install the cable into the motor, pull fuse #37 so I don't risk burning out the motor and leave the spoiler in its "semi-erect" position until I get the car back. Then I will look at performing a bearing-etomy on the mechanism in a few days. $5 for two 625-2RS sealed bearings on eBay that should get to my house in early July.

Did you rotate the flex drive to check for spoiler movement?

I did this. be careful when you prise apart the case, you need to keep the faces as clean as possible for the glue to work................
https://cimg9.ibsrv.net/gimg/rennlis...d9240754c9.jpg




https://cimg1.ibsrv.net/gimg/rennlis...b4df4be1cd.jpg

There are three 5mm allen head bolts holding the gearbox in place.


https://cimg9.ibsrv.net/gimg/rennlis...42d677d18a.jpg


Using a razor blade, box cutter, exacto knife and small screwdriver carefully pry open the gearbox. Don't force anything, go slow, this is where you will earn your $300 in savings.


https://cimg1.ibsrv.net/gimg/rennlis...3a5a86d888.jpg

https://cimg2.ibsrv.net/gimg/rennlis...4d6d3ed056.jpg

Can you spot the problem in this picture? [rusted out stuck bearing]


https://cimg3.ibsrv.net/gimg/rennlis...3a90406e17.jpg


I popped out the bearing per ToreB instructions:


https://cimg4.ibsrv.net/gimg/rennlis...b7512eca1d.jpg


I cleaned all the parts carefully, and here is the exploded view of the bits ready to go back together. Note the new sealed bearings ($5 for two 625-2RS sealed bearing on eBay). I need to order some Lithium Grease to lube up the gears and will post how it goes back together after my vacation. I will also take the opportunity to lube up the cable in its sleeve as well.


https://cimg6.ibsrv.net/gimg/rennlis...a0fd169b85.jpg

Great write-up and photos!

I hope your case glue works better than mine which keeps failing!

What glue did you use? I was planning on Loctite 2 part 5 minute epoxy.