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'80 450SL Drivers Door Lock

2K views 2 replies 2 participants last post by  BCLEM 
#1 ·
Well I'm steadily wading thru all the various issues with my newly aquired 450 and thought I'd tackle a problem it has with the drivers side door lock. If I lock the car from the driver or passenger side with the key all the locks perform as they should but if I unlock with the key from the driver or passenger side all the locks unlock with the exception of the drivers door.

I can unlock it manually from the inside but not by useing the vacuum system. So basicly everything is working as it should with the exception of the drivers door lock which will lock but not unlock via vacuum. Any tips on likely component failures that could cause this would be greatly appreciated.
 
#2 ·
I'm not sure where you are from, and/or if you have a RHD car.

Be aware that on a 450/380SL, the driver's door is the MASTER for all of the others. Unlocking the passenger door or the trunk with the key will NOT unlock anything else.

This is not true of the 560, which has electrical switches and an electric vacuum pump in addition to the vacuum system and reserve. With not electric vacuum pump, note that the 450/380 has a vacuum reserve for only "several" open/close cycles with the engine off.
 
#3 · (Edited)
Found the problem :) . I took the latch and outer door handle assemblies off and figured out that the little "L" shaped lever on the end of the lock mechanism was adjusted a fraction too "deep" and was not making a good contact with the part it acts against in the latch mechanism. Luckily it's depth is adjustible so I readjusted it a tad shallower so that it made better contact. I greased everything up real good and reassembled the door and now it works like brand new.


I'd like to add this note for the benefit of other 107 virgins that might run across this thread in the future. The door locks on these cars are mechanical in design meaning that when you turn the key in the handle you are turning a lever inside the latching mechanism that, depending on whether you're turning the key cw or ccw, mechanicly lifts or depresses a part in the latch. Vacuum is not necessary for the lock to work.
The central vacuum lock system is controlled by a vacuum switch that is mechanicly linked to the drivers door lock actuator. When the drivers door lock is engaged the linkage moves the vacuum switch and directs vacuum to the remaining locks, either locking or unlocking them depending on how the drivers lock is set.
 
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