Rear Door will not open

mercedes-benz
s-class

#1

I have a 1997 MB S320 LWB that I want to get repainted as the clear coat is failing. The problem is the left rear door will not open. You cannot open it from inside or outside. I tried the push pull method shown on you tube. I butchered the inside door panel to get to the locking mechanism. But the critical door locking mechanism isn’t accessible from inside the car because of a metal plate. From what I can see and operate the central locking system linkage is connected and operate. The inside door handle linkage also is connected and works. The outside door handle works.
I have a replacement door lock assembly that I purchased off of ebay. I see how the door lock mechanism works. Using and endoscope I can see that most of the mechanism is ok. The problem seems to be that the hardened steel lock ring that is supposed to rotate when the door is unlocks lift a lever that raises a pawl that releases the door locking ring. A torsion spring is suppose to rotate the locking ring to the unlock position when the pawl lifts. Apparently it is frozen. I have tried spraying wd40 to free it up to no avail. Removing the door hinges would help because the locking ring will still be inaccessible. Any suggestion on how to get that locking ring to rotate so I can open the door, replace the door panel and get my car painted?


#2

Well, since you’ve already “butchered” the door trim panel, you might as well go online and search for a complete pre-owned door, including the trim panel.
You could luck out and find one the right color near your location. Be sure the trim panel is the correct color and correct operating mechanisms.

Then, once you’ve got it, any body shop, they all have nibblers and air chisels and experience, could remove the butchered, screwed up door and Voila! You’re golden!

That was easy! Next!
CSA


#3

you may want to stop by an auto body shop and see if they can help.


#4

I certainly can’t diagnose your door lock online, but I can tell you the WD-40 is not the lubricant you need. It is really not a lube at all, it’s a solvent with a water dispersal agent (hence WD). Get a spray of white lithium lube. It might help. Maybe.


#5

Yeah I’d give it a day with PB Blaster or something (not LW) but I did use WD 40 on a stuck water hose connection and it did work. I had a stuck drivers door and consulted a body shop. I said I was ready to cut an access hole in the door and they said that would be the last resort. I got very aggressive with it and it finally opened but my next step would have been to get the angle grinder out and cut an access panel. Going to be painted or replaced anyway-just don’t distort it too much so you can pop rivet the panel in again and 5 hours of body work prior to painting. I think my problem was the door lock solenoid stuck a little so didn’t completely unlock the door. Got a child lock switched on? That’ll disable the inside handle.


#6

Remove the inside door handle and spray penetrating oil at the base of the door rod mechanism.Grab a pair of long nose pliers and pull the rod a few time until it unseize.It always work for me!


#7

Looking on ebay for a replacement lock I found that most of them had corrosion in the area of the locking ring. I have lithium spray buy that is too viscous to soak into the pivot for the locking ring. Once I get the door open and can get the lock out I’ll use lithium grease after it’s freed up.
Dan


#8

WD-40 contains a light oil lubricant.


#9

Success! I got the door open.Wow it wasn’t easy but I figured it out. I took a 1" hole saw and cut a hole in the inner body structure that is inside the car. That gave me access to a small existing hole that was close to the lever and pawl that releases the locking ring. With a scribe I lifted the lever but no response. Then Looking at the ebay door lock assembly I saw I needed to be over about 1/2".
I drilled a another hole and could now get the both the lever and the pawl that holds the locking ring in place. What happened was that each time I raised them then the central locking system would actuate the door closing system and the door lock would relock. I removed the fuse for the central locking system but the door closing system still activated. I figured out how to trip the pawl and operate the door handle before the door closing system could actuate.
We are under an extreme heat advisors and have a terrible air problem from smoke from some wildfires so that is all I can do today. Here is the real problem. I don’t think the door lock mechanism can be removed for the door. The inner door structure is spot welded to the rest of the door frame. Is there a way to upload a picture so I can show what I mean by the door lock mechanism can’t be removed?

Dan Mauch


#10

When you are in the reply window, look at the buttons above the text area. Click on the button that looks like a line with an up arrow coming out of it. On my screen it is the 4th button in the 2nd section (going from right to left) (or if you’d prefer, it’s the 7th button in from the left)


#11

So does salad dressing, but it’s not a lubricant, either.


#12

With the door lock out I figured out what the problem that caused all the work to get my door open. There is a short roller link that if stuck in the locked position prevents the two levers that lifts the pawl to release the locking rins so that the torsion spring can rotate the locking ring to the unlocked position. Herer is a video of my lock and the problem roller link.

Dan Mauch


#13

A little silicon spray would probably help from getting stuck again.


#14

Sounds like time for a little preventive lube/solvent on the other doors while you can still get them open.


#15

I already sprayed the door lock with lithium. That should stop it for ever freezing up again.
Dan


#16

I have already sprayed the other door lock mechanisms as best as I can without taking stuff apart> Even if I were to take the outside door handle off there is no way to get to the roller link that caused the problem.
Dan


#17

Most cars manufacturers install child safety locks in the rear doors and maybe they got stucked.


#18

Now that you know where to drill the holes for access . . .


#19

Different cars have different systems. A few years ago, I took my ‘grand-daughter’s’ family to visit family an hour away. We went into the local market place. When we came back to the 2002 Sienna, the left rear door would not open. We used the other door. Later, when we had time, I asked my cousin-builder to take off the door liner. Then, I told him to go back to his work while I just sat and looked at that mechanism.

After while, I realized the cable that came into the mechanism has three little metal beads on it, obviously so it could be adjusted. I moved it to the next bead and the door worked perfectly again. Then, I asked the cousin to reinstall the door liner again. Saved hundreds of dollars for a new door mechanism, plus labor.

There was great enthusiasm when I posted a photo on Sienna Chat with instructions. It turned out a number of people had those mechanisms go out of adjustment. Toyota certainly never documented it anywhere that I could find. And, I was sure if I had taken it to Toyota, they’d have installed a new mechanism at great expense. That would be the current business model.


#20

I’ve had pretty good results from a youtube search on the two occasions I had door lock issues. It’s certainly not perfect, and some of the results are very amateur, but it did give me enough info to get started and to figure out ways to cope with very tight spaces.