Check some other good Door Tech Tips -- and we have a forum devoted to "The Doors" -- old truck doors, that is. After all, ... don't you love her madly? -- most of the time!
Hang them dang doors. That round pin doesn't fit into that over-sized hole anymore!! Dang door! Besides the hood alignment, this seems to one of those tasks that you avoid. (Are you still driving around with a rag hanging out the door jam to keep it shut?). Well, Mike has some good step-by-step instructions of rebulding not only the door hinges with focus on the pins but the bushings as well. A little effort ... a little money ... and you've got some smooth operating doors!
A bit of a design flaw
There is another very good technical article on Stovebolt concerning replacing door hinge bolts on your old Advance Design Chevy truck with oversized pins by Brian "MARTINSR" Martin. My article, while similar, deals with the additional procedure of adding bushings.
The door hinges on these trucks are of very poor design by failing to have anti-friction devices and are prone to corrosion. The corrosion results in pins that seize to some hinge parts, while unintentionally spinning the pins in other hinge parts causing wear to the pins and holes. Once the holes are oversized and pins undersized, the door begins to sag -- all making the door difficult latch, unlatch as well as swing open and close. The worn parts accelerate wear until the pin fails.
Replacement door hinges cost $150 to $180 a pair for only one door (Fall 2012 pricing). You can purchase oversized pins ($4 to $8) that require you to drill the holes but this does not address the lack of anti-friction or anti-wear devices.
The original hinges do have a hole for lubrication but these ports are horizontal, located at the pin midpoint. Trying to get oil to flow horizontally causes just as much oil to backflow on to your running board as towards the hinge pin; while gravity keeps the oil from flowing above the hole. Oil also works against you in this application, as it soon accumulates dust and dirt causing parts to stick -- accelerating wear.
The best solution available for these hinges is a pin and bushing kit (figure 1) with the cost ranging from about $12 to $20.
Instructions were included with the kit but applied to hinges that already had the bushings.
My research in Chevrolet manuals never revealed the names of the hinge parts. So for this article, I will use the terms “hinge plate” for the part that bolts to the cab (front pillar) and the “hinge arm” that slides into and bolts to the door.
The first step is to remove the hinge pin from the hinge. An entire article could be devoted to this, one on truck with four hinges I had to use several methods, some different from one hinge to another. You can use a press, a pin or drift punch and hammer, penetrating oil, a torch, hacksaw, cutoff saw, whatever it takes.
One thing that was consistent is the hinge pins were corroded to the part that is supposed to ... was supposed to ... swing freely -- the hinge arm. Heating the hinge arm around the pin to a red glow released its hold on the pin in all cases. Then a punch and hammer finished the task.
The upper door hinges (are supposed to) have two “C” shaped springs. The next three pictures below (figures 2, 3 and 4) should reduce cursing and make the disassembly job more enjoyable.
Now it is time to carefully measure the (smooth portion of the) pin diameter and choose a drill bit the same size. I recommend using calipers or a micrometer then converting the decimal size to fractional drill size. Or better yet, use a number sized drill bit should you have them.
While measuring and selecting the bits, choose a bit that slides in the current holes as well as one that fits the outside (smaller) diameter of the bushing. The pin in my kit needed an 11/32” drill, while the bushing required a 27/64” drill bit. I did not note the size of the bit that fit the current holes as this can vary depending on your hinge wear.
If you do not trust your skills at measuring, converting measurements and selecting drill bits, do a simple test by drilling a piece of wood, plastic or metal with the bits you selected then place the new pin and bushing in the test holes.
I started by drilling the hinge plate holes. You could start with the hinge arm. Just make sure you do not get the bits mixed up, saving the largest bit for the hinge arm as it holds the bushings.
For precision and safety, it is best to use a vertical mill or drill press. You can use a hand held drill but be careful as the bit will catch a burr close to completing the drilling of each hole. The torque of the drill motor can exceed your hand holding capability resulting in some unpleasantness.
To correct the problem, I put the hinge arm back in the vertical mill vise using the drill bit to ensure the hole was vertical.
Then using an end mill, I removed some material from each end (figure 10).
I used the vertical mill because I have one. It’s easy, quick and accurate. You can still get great results with a file, bench grinder or hand grinder.
Reducing the hinge arm width is a better choice than filing the hinge plate. The hinge arm has more material that is more solid and easier to access than the hinge plate surfaces. Machining the hinge arm surfaces flatter provides better support for the bushing shoulders.
I used a lathe. You could use a hacksaw, power saw, cutoff saw. Most important: clean up the end with a slight rounding or chamfer -- this makes inserting the pin much easier.
Before assembly, I lubricated the pin and insides of the bushings. I use dry silicone spray lubricant. It leaves no residue to attract dirt like oils do.
The pins should be placed with the head at the top. You must study the hinge plates to get this right because while they are symmetrical, when installed on the truck, they face in opposite directions.
Figure 12 on the right is an image of the left door hinges with the upper hinge on top and the lower hinge at the bottom of the photo. Note the top of the top hinge plate has the single bolt-hole while the lower hinge plate has the single bolt hole at the bottom.
Recall the upper hinge set has the “C” springs so the hinge plate will have slots cut in it at the top and bottom and the hinge arm has a hole drilled in the top and bottom. The upper hinge arm is the shorter of the two.
Putting it all together
I felt it was best to start with assembly of the lower hinge first. The practice makes the upper assembly easier.
To get the pin in all the way, I used a vise to support the lower portion and a couple strikes of the hammer. You could use the vise to press, or a press. With clean new parts, it goes pretty easy.
Below is a series of four photos (figures 13 through 16) assembling the upper (left door) hinge set with the two “C” springs.
Secure the hinge arm in the vise, then put on the hinge plate on “too far.” Then wiggle in the springs and bushings. Slide the hinge plate into proper position. Insert pin from top.
With the upper hinge fully assembled, the springs cause a lot of resistance. This resistance is normal. Once your door is attached, there will be a lot of mass helping as well as a lot of torque.
I finished with another coat of primer waiting until final paint to lube again. There is really no need to squirt lube in the factory hole. There is now no contact between the pin and the hinge arm. So a little squirt at each bushing will keep it operating smooth, and again -- dry lube.
Our final image is a finished pair of hinges