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Old 10-25-2012, 11:04 PM
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bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
Join Date: Mar 2008
Posts: 25,236
Mein Auto: 02 BMW 525i M54 auto 130K
I practiced removing the spring off the cable a few times.
Of course, strong tension is gone - but, I proved to myself the concept of removing the spring without disassembling anything is sound; so, here's my proposal (for the next person) of the trick to loosen cable tension without disassembling anything else:

To loosen cable tension, this may be the best potentially viable approach:
  1. Measure the current location of the black ribbed plastic large-spring stopper
  2. Push the black ribbed plastic large-cable stopper in all the way
    • That, in and of itself, may provide enough tension relief
  3. If not, first, you may have to pull the black ribbed plastic large-spring stopper out an additional inch or so
  4. Then, unwind the large spring off the cable (like pulling a key off a keychain)
  5. When it's time to replace the spring, wind it back on (like putting a key on a keychain)

Had I known that potential trick of unscrewing the large spring, my regulator would never have been taken apart ... but ... I guess someone has to take the hit so that the next person has an easier time of it.

The good news is I now know more about this window regulator than I ever wanted to know - and I certainly have learned a host of things NOT to do!

The bad news is that it would take a minor miracle to get it all back together again.

Things not to do:
  • In hindsight, I wish I had marked the location of both window clamps to the guide rails because they probably need to be symmetric on the rail cable guides when I restring the cable.
  • Also, I wish I had marked the amount of cable wound inside the spool because that is probably a critical dimension (I should have put a dab of nail polish on the two cables at some strategic point)
  • I wish I had marked the original length the black ribbed plastic large spring stop stuck out of the motor (as it can move at least an few inches either way).
I'll ask MatWiz for advice how to proceed ... he (Dan) seems to be the only one who documented the motor disassembly (but he stopped half way when his camera battery died):
-> E39 (1997 - 2003) > Front Window Regulator - Re-Assembly Instructions.

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Please read the suggested threads and add value, either by pictures or by descriptions, so the next person stands on your shoulders.
See also: E39 Bestlinks & How to easily find what you need

Last edited by bluebee; 10-26-2012 at 01:35 PM.
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