I am wondering how I can tell what K member that I have. And where it was made? I have two Dusters that I can compare, a 1970 and 1972.
I can offer some insight as to how the K members were manufactured because I helped to maintain the process to manufacture them that used for some, but I'm not sure which vehicle the K members that we made were used in.
Generally, the individual parts of a K-member (k-m) were stamped out in a "heavy"
stamping plant. There were more than three plants before consolidation but afterward there was Twinsburg, Warren and Sterling Stamping Plants in the 1980's and beyond. This is not to say there was not some satellite operations near a vehicle assembly plant, or "re-strike" presses in an assembly plant metal shop. Regardless, the parts (of a k-m), were brought from the stamping side of the stamping plant, to the sub-assembly side and welded together before shipment. Even today, there are these hybrid plants, that stamp on one side and sub-assembly on the other, at Ford, GM, and Chrysler. Forget Stellantis, I'll never call the Corporation that!
The welding process, where I was, consisted of three or more presses with a transfer "shuttle" to advance each part. At the end of these presses were the welders, using hand-held manual wire welders, to finish the process. All this was prior to any robotic welding, which we installed later, in the late 1980's and currently.
Weld quality was checked by "weld destruct testing". A maintenance person or an inspector would use a hammer and a chisel(still have it), to physically rip a panel, part, or k-m apart. Very difficult on thicker metal without an air tool. After "weld destruct", the welds were measured in two directions with calipers and averaged the two. The weld was called a "nugget". If a nugget was pulled from one side (part) or another of sufficient size, it passed inspection. If it was undersize, it could be grown to size with more current. If no nugget at all, it needed at least time and maybe more current.
Problems with welding: #1-Fit-up. If parts didn't conform to each other before or during welding, 5% more force was allowed per Chryser Standard, to compensate. Just remember, when resistance spot welding, adding force may require adding more current.
#2- Dirt, drawing compound, grease. This comes from another process (stamping) or poor storage. These can comtaminate the welding electrodes and require changing them to fix. The electrodes are a copper alloy, copper is soft, and easily accepts harder materials to be embedded.
#3- Off location. Most common welds off location are edge welds.
#4- Missing welds. Surprise, some welds were allowed to be missed per Chrysler standards. IIRC, no end welds should be missed, no two in row welds, no "Federal Welds" missed. I have the Standards somewhere here. I helped develop the one for Aluminum welding and corrected the early robotic standards.
Spot inspection consisted of looking at the spot welds and counting them. I could tell a bad weld sometimes but I never blessed a weld as good without some form of test. It can't honestly be done, the blessing that is, but after changing the electrodes on third shift, at 6am, we used to say "If they're Golden They're Holden". The welds had a Golden hue from fresh copper electrodes so we would say they are good.
Resistance Spot Welding has been around for many years but has changed dramatically since then. The most dramatic change is the use of inverters. This, along with other technology, enabled a robot to carry a welding "gun" by lightening it enough to meet robotic payload requirements. The 75-90 KVA transformers were heavy. Even a 210Kg payload Fanuc robot would struggle to meet cycle time with one on it's arm. Don't believe it? Then air up your tires, go to Weight Watchers or Zumba and pick up passengers. How fast can you go now? Then go home and change your shocks.
Before that the guns were all "hanging" guns or hydraulic guns in presses like the k-m line.
K member Line function: The parts were loaded the first press in line by the operator and after the palm buttons were pressed, all the bottom presses went up (hydraulically with a Rotac) to meet the welding guns at the top of the press. There were stationary electrodes under the parts and the upper weld guns were extended at this time to pass current through said electrodes and create a spot weld. The shuttle had returned from delivering a part (when forward) so when all presses then went down, shuttle went forward, and the operator could reload the first press, and process continued. The welders after the presses then seam or butt welded the k-m before shipping. Lots of smoke, hot parts, and even some phosgene gas to breathe.
Some welds that I observed were termed "suspect welds". Misalignment, of the two electrode caps of the weld guns could create a suspect weld. We used two Main size caps, maybe 5/8" and 3/4" electrodes for spot welding, they were round nose, called "B" caps. On this line though, at this time, flat caps were commonly used because it was easier to correct electrode tip misalignment, with a flat cap. A flat cap required more current to create a good weld, but it helped to prevent distortion in the metal when the mis-aligned weld guns were extended to weld.
As far as the weld controller was concerned, a minimum of three instructions were needed to be programmed to create a weld.
They were called: Squeeze, Weld, and Hold.
Squeeze: Was a long used term for the time period that the parts were pushed into contact with each other. Force was used (and measured between the electrodes) to squeeze the parts together for welding. I never used less than 450 lbs. of Force in forty years of automotive welding But, proper Force is determined by metal type, thickness and coating, primarily. Altering any of these three can necessitate changing Force settings, But these settings are not programmed into a weld controller.
The Weld instruction is only a time period (of passing current) and of current. I never used less than 6-8000 amps for automotive cold-rolled steel of light thickness, like hood or door "skins". I believe the highest that I ever asked from a weld controller was 60,000 amps, but that was much later, in 2005, with an inverter, and the electrodes were nearly destroyed by then due to the amount of welds on them.
The Hold instruction was simply a time period to wait for the weld to solidify from a plastic state. These time periods were programmed in "line cycles". So, 10 cycles (10*), equals 1/6 of 60 cycles per second. Nowadays, for the last 20 years at least. we program in milliseconds and no one even remembers "line cycles".
Maybe next Chrysler history could be Plant shootings, robberies, truck hi-jackings and crazy employee activities? It was a wacko place to work from 1960's to 2007 for certain. When I started there were people who worked there before WWII. They mentored me when I hired in. I was looking for a Father figure anyway. Those guys were an entirely different group of people. Remember what your parents or Grandparents were like?
