300SD Rear Door Makes noise
 

Happy New Year, Thanks for reading,

The rear door behind the driver does 2 weird things.

1. You really have to slam it to get it to hit the second catch and lock. If you don't slam it, it will only lock on the first catch. Not really know if "catch" is the proper word or not, but it seems to have like a half way catch point and a full closed catch point.

2. When this door is opened it feels a little hard to open, guessing twice the force to open compared to the other rear door. Also, when you get to the Detents, where the door can be left sort of in a slot, it creeks like it needs lube or something, then when you open it further past then Detent, it is hard to get door out of the first detent and it creeks again. Sort of what you would expect if there was rust or crud somewhere.

Thanks for any assistance.

Enjoy you the New Year!

Needs a good lube, I had this problem with the back door on drivers side. it went for years without being opened. Flooded with atf & all was good.

Do I need to take door panel off to do it best? ATF huh? I have some of that.
Thanks!

The metal strap that limits how far you can open the door is known as a "door check". There are several good threads on here about how to service them.
Door card removal is required.

Sounds like a door stop problem.

1982 Mercedes-Benz 300SD Base Sedan - Bumpers, Doors, Latches & Lids - Page 1

That is the part that holds the door open. It is inside the door so the door panel needs to be removed to get to it. You can try spraying WD-40 in the hole the arm comes out of and see if it helps.

Someone that is better than I am at explaining can chime in.

Get the problem fixed before you use the door anymore. It will completely fail then the door is open and the door won't close again.

Paul

Do a search on "door check" and replace yours if it is beginning to not work smoothly every time. You may get stuck with an open door if that is the problem.

Not closing is likely the bumper that trips the latch. Look at the other doors especially the passenger side since they don't get used much. You'll see an aluminum piece surrounding black plastic and held in by 2 bolts. The plastic that sticks out gets worn or broken causing the latch not to work. The piece is side specific but the plastic tongue can be swapped to either side. They are cheap or free in the yard as the counter person frequently doesn't know what they are. Multiple years, models, gas/diesel all have the same part. You need an allen wrench (socket) to remove. Tap the socket in with a hammer to get a good fit and shock the bolt for easy removal. I've had the head strip & require easy out.

Regarding noise, either door check, lack of door hinge lube or worn door hinge. To check for worn hinge, open the door. Grab the back end and lift. There should be NO play. Again, multiple cars use the same hinge. The passenger side is frequently good.

actually, you have TWO problems...
one, your door latch is missing the plastic ramp that actuates the latching cycle.
two your door check is either dirty or warped, causing a need to either clean and lubricate it, or replace it with a new one.

The door hinges also need to be lubricated. The hinges are completely accessible without removing the door panel (card). Use WD40 or PCB Rust Buster with the red straw like nozzle. While spraying both the top and bottom hinges open and close the door several times. Lubricate the door stop also. I had the same problem on my 300D (seldom opened the back doors) and the lubricate fixed the problem. I would also lubricate the other doors and the hood hinges.

SD hinges have grease fittings.

Ok, I didn't know that. Looks like he will need a grease gun. Thanks

OK and Thanks for all the replies,

I went around and lubricated all the doors with WD40 and also the Hood Hinges.

I used a WD40 can with a stray to spray sideways inside to lubricate that door stopper mechanism stuff inside the door and also the (2) door hinges per door.

I see that there was something that looked like it needed a grease gun for the door pins, hinges, but my grease gun fitting is different.

WD40 seems to be freeing it up. I will spray some all around the doors and hood hinges as Hunter recently mentioned the hinges are expense if they get bent.

Thanks to ALL

Steve

Wd40 with a straw not a stay, sorry typo.

126 door hinges have a small tapered hole. You use a grease gun with a pointed tip on it. You can find them in the chain saw department of most big box stores. They are used to grease the chain saw bar.

Paul

And the hole is supposed to be closed by a small, spring loaded ball bearing that frequently is MIA at this age.