The Stovebolt Site Forums The Shop Area Paint and Body Shop Doors door hinges

Just got done rebuilding 4 door hinges. I have rebuilt plenty of them over the years.
All of them failed for the same reason as all of them do. Lack of proper lubrication between the pin where it rides inside of the hinge strap. There is an oil in the binge strap for that, but nobody seems to have known that.
Once the pin seizes to the hinge strap, all of the rotation takes place at the very end of the pins at the stamped metal of the hinge body. That is where all of the slop comes from, and very rapidly.
All four of the pins had a close fit within the hinge strap, but the holes through stamped metal hinge body were wallered out.
Over-size pins were needed to restore to usable condition.
So I started thinking about how this could be avoided in the future even if the hinges were not oiled often enough.
If the pins begin to lockup, it doesn't take long for the serrated section under the head of the pin to give up and pin begins to move in the hinge body without any telltale noises or increased effort in opening or closing the door.
My solution is to tack weld the pin to the body so that it forces the pin to continue to turn inside of the hinge strap and hopefully begin to squeak when the pin begins to want to seize so you will know to oil the hinges.

What I did was drill the hinge strap oversize and install brass bushings at the top and bottom of the strap. The bushings are less likely IMO to seize in either the pin or the strap. The serrations should hold the pin in place without tack welding, although that is a reasonable approach as well.

I did see the oil holes in the hing strap, which is accessible when the door is opened. Oiling them on a regular basis should help preventing the pins from seizing the straps also.

I think the bushings I used were bronze. They were part of a kit.

I've tack welded the pin for many years. It is a very good way to secure them. Often the washer (spot welded beneath the hinge piece) will separate and that leaves only a small bit of metal for the hinge pin serrations to grip as the washer will just spin after that. My experience has been you will hear the driver's side or feel it not working as well because you use that door most often. On the passenger side you may not ever know there is a problem until the pin rusts in the strap hole and then it just won't work any longer and you have to force the door open and repair it.

Many automotive hinges today use a high tech plastic bushing (probably Delrin which is self-lubricating) that of course won't rust and wears very slowly coupled with a stainless steel pin that does not ride inside a strap hole like the old style did. Some bushings are thin, machined to the same size as the pin and sort of fragile looking and others are fatter and resemble a stepped faucet washer. I've thought of trying to find some Delrin bushings that could be used on the AD hinges so that the strap hole could be drilled larger than the pin and wouldn't be prone to seizing. My experience has been a lot of people mean to lubricate them, but don't always do it. Lubriplate or that thick red motor assembly lubricant is good. It tends to stay put and lasts a good long time. Not too easy to force through a small hole, however.

Here's a pic of the bushings I used. Pretty readily available at parts stores to fit the oversize pins that are available from vendors. They're hat style so also bear against the washers in the hinge frames. I also welded the washers in place on the frames.

Has anyone put a grease nipple in the oil hole to force grease into the bushings? I read that somewere but I don’t know if it was possible to have a grease nipple sticking out or if it would get in the way of the hinge movement.

I tried doing that around 1976...drilled and tapped a hole, installed a grease nipple but it didn't work as I had hoped. To get the nipple where it was accessible to my grease gun it stuck out too far and interfered with the hinge pocket in the door. Could have been the way I did it and maybe somebody else figured out how to do it differently. All I managed to do was make the oil hole much larger.

Good to know ,thx