10-25-2012, 08:55 PM
Seek to understand,^Value
Location: San Jose, California
Join Date: Mar 2008
Mein Auto: 02 BMW 525i M54 auto 130K
The cable came off in testing - but I don't think it was due to the chipped roller; I think it was because I had not tightened everything - and/or because the window was out of adjustment, as there is not a well defined procedure (despite the Bentleys, which are worse than confusing) for adequate adjustment of the stops.
Originally Posted by dvsgene
did the cable just come off while in operation?
BTW, I pulled out the square plastic bolt - but it doesn't seem to be of any benefit in loosening the tension. All it does is plug the hole, perhaps so that we can add grease to the motor helical gear.
At some point (I don't know when), the smaller springed tube fell out of its slot in the motor housing.
In hindsight, here is how that tube 'should' have been reassembled:
Another mistake I made (of many) was to not realize that this ribbed black plastic spring-tension adjuster might be a critical component in loosening cable tension!
I should at least have marked the initial location of the black plastic large spring stop, so that I would know how much to push it back into the motor when I put it back.
Here is that black plastic ribbed spring stop, almost pulled out:
I spent some time trying to figure out how that larger black plastic stop goes into the motor - and finally concluded it's a press fit - which takes a LOT of force to fit inward - and which is mighty hard to perform with that heavy spring in place (more about how to conquer that all-important heavy spring comes later).
While I was examining the motor for how to release tension, curiosity got the better of me.
This gear is what spins the coils of cable.
Notice each coil is wrapped around the takeup spool twice, in opposite directions.
The large spring cable is coming in from the left; the smaller spring cable comes in from the right.
Within seconds of snapping that photo for you, as I put the camera down, that nice arrangement of cable coils literally unwound in my hands.
Leaving me with an unsprung front window regulator takeup spool.
After all this - I belatedly realized (what might be) the trick to reduce tension on the front window regulator!
Look at this picture below.
Notice you can easily unhook the heavy coil spring from the cable, and hook it back up easily after the fact, simply by unwrapping it from the wire as you would unhook a key from a common keychain.
I'm guessing this spring unwrapping can be performed without disassembling anything!
If so, that's the trick to releasing tension (WITHOUT DISASSEMBLING ANYTHING!)
It's too late for me to try this trick - but - if I had known that I could simply unwrap the heavy coil spring, I would have tried that, instead of ending up with motor parts all over the place.
Last edited by bluebee; 10-26-2012 at 05:38 PM.