The latch mechanisms are not overly complex, what do you mean they "extremely hard to open"? Are they hard to unlatch or actually open (as in pull out from the car)?
Let me say this up front, these doors do not and never did open like a modern car. They tend to take a little effort and always did even when pretty new. If you spend enough time adjusting the door you can find a sweet spot where they open pretty good; meaning that when you pull the latch the door releases and begins to open. However, it doesn't take much at all for those doors to sag even just a little and cause them to be a PIA to get open. If you ever met a body guy who worked at a Mopar dealer back in the day they would tell you how many new E bodies they would get in with exactly this complaint. There are 2 issues at play here, first is the overall size and weight of the doors, they are very long and pretty heavy (especially the PW variety) which equates to a lot of leverage on the hinges. Second is the flush mounted door handle design, which this looks awesome, it does not provide a lot of purchase when trying to open the door, if there is any sticking or sagging of the door, that little latch is what takes the pain (which is why so many of them were and are broken).
Back in the day, we used to unlatch the door and try and pull up slightly when opening it which seemed to help.
I am sure you have already done this but just in case; the latch mechanism when new was infused with a sticky type grease which by now is probably closer to cement than grease. Just spraying it with WD40 or something usually will not help a lot, might short term but not over the long haul. I usually remove the latch, put it into a parts washer and spend some time getting as much of that grease out that I can, then put some white lithium grease back in, I have had really good results doing this.
Another thing to look at; the rods. Over the years those rods get bent a little, just enough so that opening the door is a real pain. On my Challenger I had to pull the rod from the inside latch and beat it straight (where it is supposed to be) because there is a slight bend on one end (where it attaches to the latch) and the rod will bend there which reduces the amount of stroke you get when you pull on the latch. I found that after straightening it, it was much better BUT that latch needs to be working really smoothly or you just bend the rod again.
The door latch mech is a very symbiotic system, everything must work exceptionally well for everything else to work.
Topic: Looking for new door latch mechanism for 73 challenger (Read 856 times)
