Duetto Window Regulator Cable Replacement
I mentioned in my Duetto fix-u thread that I'd replaced the cable in the window regulator. Here are some more details about that (painful) process.
When I opened up the door it was clear that this wasn’t the first time that something had been wrong with the window winder - the cable had been cut and bolted into place on the window bracket. That worked....but it sure seemed crude. So I decided to clean it up with a new wire.
The cable is easy to find. My local good hardware store has stainless steel 1/8” cable in stock. That is the only easy part!
The tricky part is that as the window winds up and down the cable winds onto and off of the capstan from two different directions....the same groove in the capstan can be occupied by the cable from the “up” side or the “down” side! The capstan is always full of cable as it winds off of one side and winds on to the other side.
Wow. It’s like the mobius strip of mechanisms. Gazing at it in contemplation I felt a cosmic awe that reminded me of long-ago experience involving Sinsemilla and the refrigerator door light.
Here’s how I remember it all going together. The things to note are where the “up” and “down” ends of the cable attach to the capstan. My drawing is from memory and pictures taken during the process. But it looks wrong as compared to your car then it probably is. I might have goofed something up.
Well...the hard parts seemed to be remembering how the wire got routed in the door, getting the length of the cable right and anchoring the new cable ends into the capstan.
Let’s take that last part first. The window cable is similar to a bike’s brake cable. There’s a cast metal ferrule on each end of the cable that keeps the cable anchored in the capstan. I don’t have a way to cast lead(?) ferrules onto the end of cables.
But a good substitute is to cut a short length of brass tubing, slide it over the cable and then solder it in place. The solder wicks into the wire of the cable and holds fast. You need a fairly high wattage soldering iron. I used my old standby Weller “pistol grip” iron.
By the way, wicking a little bit of solder into the end of a cut cable is a great way to keep it from fraying. I do this on the ends of cables on my bicycles whenever I remember to do it - that way you can remove and re-install the cable on the road with no problems.
The cable goes through a hole in the outer circumference of the capstan, then through one side of the center of the capstan and out the other side. The ferrule gets soldered on there and keeps it from sliding back out. The “up” end of the cable and the “down” end of the cable attach from opposite sides of the capstan, 180 degrees across from each other.
You can see the cable routing and ferrule in the picture of the regulator as removed from the car. The nub on the left side is the ferrule holding the cable in place.
So, I got one end of the cable in place and wound the cable completely onto the capstan. I held it in place with a tie-wrap so that it didn’t unwrap off of the capstan.
Then I loosely bolted the regulator into place (after moving the adjustable pulley to its farthest in position) and threaded the cable through the rest of the pulleys. (The window and its support were out of the car at this point.)
There’s a guide at the bottom of the door that’s similar to a bike brake cable’s outer cable guide. It runs through a metal bracket to keep it from moving out of position. A grommet fits into the bracket but there needs to be something to keep the guide from sliding through the grommet.
When I opened up the door, that guide was held in place using a couple of cable ties. I used epoxy putty to make a couple of stops to keep it from sliding out of position. I’m guessing that the original part has the grommet molded around the cable guide.
This cable guide comes in and out when you remove the regulator, so don’t glue it in place or anything.
I threaded the cable through the guide and all the pulleys and then marked the cable’s free end where it ended up back at the regulator. At this point, I figured that it was OK to get the cable a little long because the adjustable pulley would take up some slack and attaching the cable to the window bracket would also take up a little slack.
After marking the cable, I removed the regulator (complete with the cable and the guide) and secured the other end of the cable to the capstan by threading the other end of the cable through the capstan (it goes through on the other side of the capstan & 180 degrees away from the first cable end) and soldered on another ferrule made from brass and solder.
Then I put it back into the door.
At this point, you need to remember that slack is bad. For those of you who follow J.R. “Bob” Dobbs this will be heresy. But trust me on this one...if the cable unwinds from the capstan then all hell breaks loose and rapid decisive action will be needed. So, use a cable tie to secure the cable in place so that it doesn’t unwind from the capstan while you put the regulator in place and thread it through the pulleys, etc.
Well, crap. I got the cable too long the first time. I had to take the regulator, cable and guide out and shorten the cable by 25mm or so (by pulling it through the capstan hub and soldering on another ferrule).
Did I measure the correct cable length? Umm, no I didn’t. Sorry about that. If you do this....measure the cable and post the measurement.
I reinstalled the regulator, guide, and cable and used the adjustable pulley to tighten the cable. But at some point during the process I lost tension and let slack slip in. This is not fatal. The trick is to put tension on the cable (just grab the **** thing in the middle of a cable run and pull it in to get it tight) and then wind the regulator back and forth to get the cable back into the grooves in the capstan. You may need to guide it by hand to get it started and keep it from getting into the regulator’s gears.
Once the cable is into the grooves on the capstan use the adjustable pulley to put some tension on the cable darn quick!
Wind the cable back and forth a few times from one end to the other and marvel at the cosmic one-ness of it. Then wind the cable to the “down” end and re-install the window support (and then the window). You’ll probably need to fine-tune the cable tension.
Last edited by MrZo; 04-02-2012 at 07:26 PM.