00 ML320 rear door lock not working - PeachParts Mercedes-Benz Forum

Fournier · #1 03-24-2004, 01:34 PM

Hello.

My rear driver's side door lock does not lock or unlock with the central locking, but works if you manually lock or unlock the post. If the door is unlocked, it causes an error condition when locking all the doors with the central locking. If the door is locked, central locking works fine...with the exception that it can't lock or unlock that door.

Maybe there's more resistance in the lock mechanisim than the actuator can overcome?

I assume I have to remove the door handle in order to disengage the lock mechanism. Is there more to it?

Any help is greatly appreciated.

Eric.
2000 ML320 with SkyView

supradupe · #2 03-24-2004, 01:42 PM

it's the locking mechanism that needs to be replaced. I had mine replaced due to the same issue, unfortunately out of warranty. The plunger that pushes and pulls the locking mechanish breaks, probably due to material fatigue. It is made out of plastic, one wonders why MB makes such a bad decision in the choice of material. Anyhow, it requires 2 hours of labor, the part costs about $80. If you are handy enough, you can save some $$$. I have looked into the procedure of removing the hatch door panel, it's kinda PITA.
steve

supradupe · #3 03-24-2004, 01:54 PM

it's the locking mechanism that needs to be replaced. I had mine replaced due to the same issue, unfortunately out of warranty. The plunger that pushes and pulls the locking mechanish breaks, probably due to material fatigue. It is made out of plastic, one wonders why MB makes such a bad decision in the choice of material. Anyhow, it requires 2 hours of labor, the part costs about $80. If you are handy enough, you can save some $$$. I have looked into the procedure of removing the hatch door panel, it's kinda PITA.
steve

Fournier · #4 03-24-2004, 06:33 PM

Thanks!

So, what is the procedure to R&R the lock mechanism, anyone?

I had the door panel off this past weekend, but could not immediately see what it would take to disconnect the door handle.

bigcatny · #5 03-24-2004, 10:37 PM

I just replaced my front passenger door lock. I did it myself but it was alot of work the first time. Of course I can now do the job in about 10 minutes but the first time was not easy to figure out.

I have not looked at the rear door but I'll assume it's got to be easier than the front because it has no door lock cylinder. However if it's setup is like the front (and I suspect it is) You will have to drill out the pop rivets that hold the track for the window in place. Afterwards you will have to repalce the pop rivets. This is the most pain in the ass portion of the work. If your not comfortable taking a drill to your car you may just want your mechanic to do it.

I will take a look at my door and see if it's the same and post when I get a chance.

Basic directions are:
Make sure window is all the way up and closed.
Remove interior trim panels.
Detatch cable the connects lock cable to door handle.
Unscrew the screws that hold the lock in place (2 on the front lock, plus it's also held in place by the lock cylinder that needs to be taken out)
slide lock out.
You may have to remove one window track.
Reverse to install

The lock mechanism has a long cable built into it. This cable attaches directly to the door lock handle on the inside door latch.

Fournier · #6 03-24-2004, 11:59 PM

Cool! Thanks.

Yeah, I was wondering if I had to drill those out. I assume I can order the fancy offical MB rivets to finish off the job.

Eric.

Gilly · #7 03-25-2004, 05:07 AM

Yup, I would think most dealers would stock the rivets, and maybe even the latch. The problem with the big fancy rivets is that you need a big fancy rivet gun to install them. The one we had in the shop is called "Big Daddy"(yes, it said this on the tool), so try doing a web search on Big Daddy Rivet Tool or something like that and you should come up with a picture of one. Maybe you could rent one some place?
The rivet gun I refer to is pretty big, 2 or 3 feet long, and instead of something you can hold in your hands like a pliers, it has 2 long tubes (bars) which are used to operate it.

Gilly

bigcatny · #8 03-25-2004, 10:57 AM

You can defintely get the job done nicely with a "normal"rivet and tool, although I'll bet the big daddy is really easy to use. Just rent or borrow unless you have lots of things you want to rivet.

One more thing while it comes to mind:
YOu don't need to take out all 4 rivets (2 top, 2 bottom). You only need to take out 3 of the 4 (2 bottoms & 1 top) I prefer to remove the one closer to the back of the door. This allows you to slide the rail out of the way but it's easy to reinstall the other rivets later. Got the idea from looking at what was done at the dealer from the 1st time they replaced my locks.

One more thing:
ON the fronts: to take the lock out you need to release and remove the door cylinder. This is held in place by one screw that can only be reached through a hole inside the door. There's a small hole just above the height of the door latch opposite the lock cylinder on the inside panel. Mine had a black rubber piece stuffed in it. YOu need a really long hex nut tool to reach the bolt to unscrew it (5 or 6 inches?) I bought my set from the local hardware store (couldn't find it at home depot). I'll try to get details and maybe some pix's next time I goto the garage. (In the city my garage is a few blocks away and I only use the car a few times a week)

Good luck

Fournier · #9 03-26-2004, 12:00 PM

Cool! Thanks for the info.

I love it when you said "Got the idea from looking at what was done at the dealer from the 1st time they replaced my locks."

I gotta get me a "Big Daddy"! I'll have to display it in the garage where everyone can see. ; )

Eric.

bigcatny · #10 03-26-2004, 12:31 PM

you know "big Daddy" lists for $211 although I've seen it for just over $100. Not the cheapest riveter on the market but it really is very manly.......

Gilly · #11 03-26-2004, 04:31 PM

You could probably find a cheap knock-off Big Daddy somewhere also, should be fine for a home mechanic I would think.
I'd hate to try putting something like those big honkin' rivets in with a smaller, hand-held pop rivet tool. Those things are like industrial-strength rivets!

Gilly

Fournier · #12 03-27-2004, 01:59 PM

Is this a warranty item?

I just bought this 320 from a used car lot, but the delivery date was 11/2000 and the mileage is under 50k. I was reading in the warranty book that Mercedes warrants the car to original and subsequent owners.

I have a appointment this Wednesday with the dealer. Any hints on making sure this is covered...so they don't feed me some kind of story...

BTW, the harmonic balancer is showing small, but long circular cracks on the front. Is this heading south? Warranty as well?

Thanks for the help.

Eric.

bigcatny · #13 03-27-2004, 03:23 PM

I'd say definitely a warranty item. It was the first time my lock broke. Many have had the balancer fixed under warranty also. Course I cannot speak for a subsequent owner situation....

Stay firm and good luck.

Gilly · #14 03-27-2004, 04:25 PM

Yes, given those circumstances it's still under warranty, with only a few exceptions. If it was sold in Canada you may be on thin ice with it, seen this a few times. They'd probably just contact the MB warranty office and hopefully they'd approve it. OR if the car is registered with MB as gray-market or totalled there would be no warranty.

Gilly