355 Air Direction Tambour Stuck

Just wondering if anyone has had a physically locked air direction tambour?

I noticed my timing actuator hunting on ignition turn on. I removed the actuator and bench tested it. It worked perfectly. I re-installed it, and now it doesn't make any noises at all... and the air direction controls didn't work. I did the battery reset and that didn't help.

I removed the screws from the actuator so I could use it as a mechanical key to turn the tambour. I could only get about 15 degrees movement. I didn't want to force it past 15 degrees in case I broke the cogs in the actuator.

I'm not sure if it was stuck before (but the symptoms have changed from hunting to no sounds/no movement). I can't think of anything I did to the tambour during my investigation other than put pressure on the pivot point, laterally (the actuator was a tight fit).

Any suggestions? The drive on the actuator is an odd size (5.9mm) and I don't have anything that will fit in the hole without rounding it out. Is there any part of the dash I can dismantle to access the moving parts of the tambor (i.e. put pressure on the vanes)? If I remove the vents on the dash, are the vanes exposed?

Thanks.

 

Ian, I was able to access the vanes on the tambour with the center vents removed. Best of luck!

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Fantastic, Mike.

Thanks!

I just have to figure out how to get the vents out without breaking them.

 

Here’s a video from Dave Lelonek on vent removal.

 

Dave to the rescue again

 

I’ve also use the curved pick tool at the center sides of the subassemblies. They come out fairly easily unlike the side vents.

 

A possibility for having a stuck directional tambor could be some rodents living it there with chewed up debris. A shop vac could solve that. Good luck.

 

I'll make sure my bubonic plague shots are up to date I think my garage is fairly rodent proof (brick and concrete on all sides except the metal door). And the Aussie version of the black widow spiders should keep them in check.

I'll see what I have in my arsenal. The needle nose pliers seem to be a bit brutal, even with the rubber/leather wrapped around the vanes. Perhap something like a zip tie looped around the one of the outlet slats would do the same job?

 

When I was pulling on one of the vanes, the whole assembly started to move. The whole assembly was so loose, I think only gravity and some friction from the leather was keeping it in place, certainly not the clips (which were all good, but just not doing any work).

Unfortunately, pulling out the vents only gave me access to about 2/3rds of the tambour vanes. I could hear the tambour binding as I rotated it, but it was not clear where the binding was.

I don't know whether to lubricate parts (but risk disintegrating the foam/rubber further with the lubricant) or trim bits off. Maybe even part of the cylinder ends are binding. I don't want to drown the whole assembly in lubricant, though. Anything I put in there is going to be affected by hot air as well as cold.

 

Rapidly learning what not to do....

Don't use silicone spray.... it stinks up the cabin
Don't use a straight screwdriver to turn the tambour (using the actuator drive hole).... you will chew up the plastic
You can't trim the foam rubber seal using the air vent access.... not enough room and you will tear the foam

Still can't figure out where the tambour is binding. I can force it through 360 degrees. It seems to bind at two points in 360 degrees, one is not as bad as the other. At this point, I can't see any way of fixing this without removing the evaporator from the car and opening up the case.

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That's not going to happen anytime soon.

 

Ian, the door should spin freely. Can you tell if the pivot point (shaft) on the non motor side of the flay is seated correctly in the housing?

 

Hard to say. I did think of this earlier, and put a small phillips screwdriver in the centre of the hole to see if it moved about whilst I was turning the tambour. It seemed to remain centred rather than wobbling about, but I will try to check with a mirror and torch tomorrow.

 

I checked the pivot point and it looks fine. There is some up and down movement, but zero lateral movement. I started to think that the ends of the tambour were warped, but I think I may have found the problem. Behind the tambour is a thin flap of plastic which seems to be rubbing the vanes on the tambour. Oddly, the flap of plastic is sitting on a thin rib right in the centre of the tambour compartment, clearly raising the flap into the path of the tambour (hard to take a photo of and hard to describe). I'm not sure what the flap does except scrape foam off the vanes.

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I'll have to find some kind of dremel on a long stick to remove the rib and let the flap sit further back.

 

On further investigation, the tambour is binding even when that flap is not being touched by the vanes.

When I reinstalled the actuator, I had two washers left over. I wasn't sure if they were under the screws for the metal tray under the radio or under the actuator mounting screws. I'm wondering if I screwed the screws too far into the mounting holes and distorted the tambour housing plastic (so that it rubs against the tambour sides). Even with the screws out, the binding occurs, but I suppose the plastic could be permanently distorted. The washers aren't that thick, so I'm not really sure if that would be enough to cause problems.

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Update: I'm still struggling with my stuck tambour. I wasn't able to trim the foam rubber on the end of the vanes (along their entire length) due to limited access to the vanes.

I can hear the motor struggling when it hits a specific spot.... around the time the index mark on the tambour hits the 3 o'clock position... putting a strain on the ECU driver chip. The tambour actuator doesn't normally rotate from 6 o'clock to 12 o'clock, which is unfortunate, as that arc has less resistance.

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I'll just have to use the air direction controls sparingly until I can pull out the evaporator. That appears to be a dashboard out job. I thought the evaporator would pull forward, but there is a flange on the cabin side of the bulkhead.

In hindsight, I probably should have left the foam rubber uncut and just lubricated the foam rubber at the end of the vanes. It's pointless trying to trim the foam rubber in-situ.

(EDIT: I just realised I may have marked actuator rotation limits incorrectly in other threads. I'm currently trying to find my previous posts on the subject. An easy way to remember the movement arc is to look at the wiring harness on the actuator. The 180 degree arc is on that side of the actuator)