Clean and lube the latches. Make sure that the door hasn't dropped over time. The male & female alignment part of striker should match perfectly when you close the door gently. If the door has dropped, you'll be able to see it being lifted into position. The striker has to be in the correct place also.

I have started grabbing a couple of strikers when at the yard. Many are in really good shape. The plastic insert can be move to the opposite side. The entire bumper unit is side specific.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

I just changed 2 on my '82.

A quick shot of Kroil penetrating oil on each of the 4 flat head allen bolts, trip back into the house for more coffee and out they came with a previously mentioned allen socket.

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1985 300D 198K sold
1982 300D 202K
1989 300E 125K
1992 940T

"If you dont have time to do it safely, you dont have time to do it"

"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."

So a couple of weeks ago I suddenly had a hard time closing my '80 240d drivers door. Pretty soon I had to slam it VERY hard to get it to close. Against my better judgement, I drenched it in WD, no change. I read here about the strikers so I bought a cheap aftermarket online - excitedly installed it, using the grime mark to position it and ... still wouldn't close. I tried moving the striker in all different ways, nothing. I stared at the latch and compared with the passenger side and another 123, it looked fine. It rotated through both positions easily by thumb, there was no rogue trim pieces hanging up the door, the hinges look brand new (the car is beatiful) and there is 0 verticcal play in the door. So out of frustration or maybe the need to complicate things I pulled the latch assy out of the door (some kind of German voodoo puzzle) studied it for a while seemed to be working - the aftrmrkt striker rubber was hanging it up a bit, but it was pretty dirty, dirt embedded in old oil gummy crap all up in it. I popped off the plastic guard (After carefully bending the metal lock tab) and went to work on it with rubbing alcohol, a tooth brush, which got gummed up right away, then paper towels then ear swabs to get into all the tight spots- let it dry real good - then hit it with some graphite. Door StiLL wouldn't close - I adjusted the striker radically up and out and Boom the door closed. It still needs a bit of a shove -but 99 times better than driveing with door half closed. I think after some fine adjustments and the latch wears a groove in the rubber it should get better. And the key now turns like butter - I don't know if all that was necessary but that was my Sat afternoon - and my door closes
And no more WD on doors!