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By Bruce W. Maki, Editor
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Late 1990's models of Chevy Blazers and
GMC Jimmys are known to have door hinges that wear out,
causing the door to sag. These sagging doors can be fixed by
replacing the hinge pins and bushings. The parts for both
front doors cost about $20.
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Sagging doors are not just a
nuisance, they can actually cause damage to
other parts. On this 1999 GMC Jimmy the sagging
driver's door had placed so much stress on the
power door lock mechanism that an internal
plastic part broke. The driver's door would
unlock with the keyless remote, but had to be
manually locked. |
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One symptom of wear-and-tear is a
grinding, "crunching" or clunking sound when opening the car
door. I've noticed lots of Chevy Blazers that make an awful
noise when the doors are opened and closed. This is a sure
sign of lack of hinge lubrication. Every time that
noise happens some metal is being worn away. Eventually the
hinge bushings and pins will wear out and allow the door to
sag. Read more about hinge
lubrication at the end of this article.
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Door Almost
Shut:
When the door was almost shut, the top of the door was a bit too low.
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Door Fully Shut:
When fully shut,
the door was noticeably higher. This difference in height is an indication of
a problem. In this case the problem was worn hinge pins and bushings. |
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Other Reasons For Car
Door Sag:
The driver's door on my 1993
Dodge Dakota has a similar sag problem, but it's
not from worn-out hinge components. A couple of
years ago I removed the doors (and fenders, and
hood) to repaint the truck, and when I
re-installed the door I guess the hinge was just
a tiny bit lower than its original position, so
the door now sags about 1/8 inch. One of these
days I'll adjust it. |
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| Jim set up a bench with
padding to support the weight of the door while the hinge pins are removed.
Note that this bench is
the right height only because the car was lifted
up on jack stands for other repairs. Ordinarily
something shorter would be needed. |
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Jim applied a couple of rows of blue masking tape along the edges of the fender and door. |
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Then Jim applied a layer of duct tape over the masking tape.
Duct tape provides a degree of
cushioning and scratch protection, while the masking tape
peels off easily. Duct tape used alone will often leave glue residue. |
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Removing The Hold-Open Spring:
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Jim used a prybar to pry out the door detent spring. (Also called the "hold open" spring.) |
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| Removing the spring... |
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Starting At The Bottom:
| Using a punch and a hammer, Jim drove the lower hinge pin
upwards. |
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Once the pin had been
pushed through the first pair of hinge legs, the
weight of the door pinched the pin, making it
more difficult to remove.
A this point it really
helped to support the weight of the door... |
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| To completely remove the hinge pin, Jim grabbed it with a pair of Vise-Grips and hammered on the pliers. |
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Then the pin came right out. |
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Top Hinge:
| The top hinge pin (lower
blue arrow) has the head on the bottom, so it needed to be pounded
downward with a hammer and punch. |
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Closer view of driving
the hinge pin downward. |
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| With the pins removed, the door could be pulled away from the body, just a bit.
At this point that
masking tape and duct tape acted as insurance to
prevent the loose door from scratching the
fender. |
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Once the door was loose, it helped to have a
bungee cord helping to support the door.
We wrapped the cord around the bottom board of a
roof truss. The
bench (shown earlier) supported most of the
weight, while this bungee cord kept the door
from falling over.
If available, a helper
could be used instead of a cord, but who wants
to stand around holding a door for half an hour. |
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Removing Door Pin Bushings:
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With the door separated
from the car, Jim used a hammer and punch to
drive the bushings out.
The bottom bushing on the
upper hinge after being removed partway. You can
see the upper-most bushing directly above
(covered in white grease). |
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| Once the bushing was part way out, Jim
alternately used a punch
and a notched prybar to completely remove the bushing. |
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Removing the bushing on
the top leg of the top hinge. |
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Upper hinge bracket with bushings removed.
Note how the bushings are
located on the body side of this upper
hinge.
On the bottom hinge,
the bushings are located on the door side
of the hinge. When driving out the bottom hinge
bushings, the door needs to be well-supported
and held steady. |
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Installing The New Parts:
| A set of two bushings, a pin
and a lock ring cost about $5, and two sets are needed for each door.
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Note the groove near end of pin.
The lock ring goes here. |
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IMPORTANT:
Note how the head end
of the pin shaft has a larger diameter, plus the knurling to hold the head in the bushing.
The bushings have two
different inside diameters. The larger I.D.
bushing needs to be placed where the head of the
pin will go. |
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To install a new bushing, Jim set it in place on the hinge bracket.
Note: This was the small
ID bushing, because the upper hinge pin has
its head at the bottom |
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| Then he used a pair of vice-grips to
squeeze it into the hole.
The goal here is to just
get the bushing started in the hole. |
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Next he used a big punch to drive the bushing completely into the hole.
It's best to use a series
of sharp hammer taps. Serious heavy
hammer blows could bend the hinge leg. |
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Upper hinge, bottom leg:
Jim used the same procedure to
install the other bushing in the lower leg of
the hinge bracket.
This was the larger ID
bushing.
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Subtle Differences
That Matter:
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Note how on the lower hinge the bushings go in the bracket
attached to the door... |
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...while on the upper hinge the bushings go in the
body side of the hinge. |
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| Jim inserted the hinge pin into the upper bracket. In the upper hinge the pin
points upward. |
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Then he used a punch to drive the pin into place. |
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| With the pin fully seated, he set the lock ring
into the groove at the end of the pin. |
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Then he used a hammer and a forked pry bar to pound down the lock ring. |
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| The lock ring after installation. |
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Driving in the lower
hinge pin:
Remember the note about different bushing ID's.
On the lower hinge, the larger ID
bushing goes on the upper leg of the
hinge.
And both of the bushings
go into the hinge bracket attached to the
door. |
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Replacing The Hold-Open Spring
| This tool is a door spring compressor.
Note how the legs of the
spring compressor are inserted into the spring
approximately one coil away from the ends |
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When compressed, the spring is much shorter, so it can be put back into place without a fight. |
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| Jim put the spring and tool into place between the door and detent mechanism, |
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Then he loosened the screw on the compressor to expand the spring
and let it slip into place. |
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| The door hold-open spring back in place. |
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Lastly, Jim removed the masking tape and duct tape from the fender and door.
No scratches! |
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When I worked as a
mechanic in the early 1990's, we always
lubricated the door hinges whenever we did an
oil change. Lubrication is simply a matter of
spraying some white lithium grease where the
hinge pin meets the bushing, and applying some
grease to the detent roller, which is part of
the mechanism that holds the door open.
Silicone spray (such as
WD-40) is not adequate! Silicone works... but
it's so thin that it just runs off within a few
days, leaving the moving parts dry. Any type of
grease should work, but white lithium grease in
a spray can is the most convenient to apply.
I suppose a better
design would incorporate a grease fitting and
tiny passageways to direct the grease to the
moving parts... but these hinges are not that
sophisticated. I've never seen any car door
hinge design with that degree of sophistication. |
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More Info:
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Tools Used:
- Hammer
- Punch
- Vise-Grip Pliers
- Door Spring
Compressor
- Notched Prybar
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Materials Used:
- Set of Door Pin With 2
Bushings
(2 Sets Per Door)
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