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Premature Ball Joint failures on
2003-up Ram Trucks is a reoccurring problem that will
probably plague these trucks for their entire life due
to the size of the Ball Joints and the steering geometry
of the AAM 9.25" axle.
The Upper and Lower Ball Joints on
these axles are at different angles, in other words the
vertical axis of the Upper and Lower Ball Joints
are neither inline or parallel to each other.
To compensate for the different arc of each Ball Joint
during turns, the modest sized, straight shank, 7/8"
diameter stud of the Upper Ball Joint is vertically
free-floating in a 1" long sleeve.
Consequently, the Upper Ball Joint does not support any
weight, it merely keeps the knuckle in place. In
fact the upper Ball Joint is not really a Ball Joint at
all, instead it is a floating King Pin that is about the
same diameter as the King Pins found on 1966-1981 Ford
F100 4x2 1/2 ton trucks and light 3/4 ton trucks with
GVW's of 4,700 lbs-6,900 lbs..
The Lower Ball Joint is load bearing,
in fact, the two Lower Ball Joints carry 100% of the
front axle weight on your 2003 or newer Dodge Ram truck.
Dimensionally, the outside diameter of the Lower Ball
Joint is only 4% larger than the Ball Joints used on
1972-1986 Jeep CJ's (and other light-duty models of that
era) which has somewhere between 1/4 and 1/3 of the
front axle weight of the Dodge Ram, plus both the Upper
and Lower Ball Joints on the CJ are load bearing.
In addition, the Ball Joints used on older models like
the Jeep CJ and 1994-1999 Dodge Ram 2500 and 3500*
shared the same vertical centerline axis and were
pre-loaded to compensate for wear. With the
AAM front axle steering geometry using differing Ball
Joint angles, no preload is possible, therefore, any
wear means loose Ball Joints.
Yes, lack of lubrication with the factory AAM Ball
Joints can be a factor, however very few of the failed
Ball Joints we cut apart are suffering from a lack of
lubrication. Replacement Ball Joints in both
greaseable and non-greaseable versions are available
from quad4x4.com, plus there is even an offset upper
Ball Joint out there (which in my experience is both
short-lived and of limited use). Installing
Greaseable Ball Joints and regularly greasing them may
provide longer service life, but with the AAM axle,
chances are you will need to replace the Ball Joints on
your 2003-up Ram 2500 or Ram 3500 4x4 truck every two to
three years. One would not mind the short Ball
Joint life so much if these trucks steered better than
previous models, were not subject to "Death Wobble", or
had longer tire life.
*1994-1999 Dodge Ram
trucks with the Dana 60 Front Axle have Lower Ball
Joints that are nearly 10% larger than the AAM axle.
Average Ball Joint life for 1994-1999 trucks is close to
150,000 miles or 7 to 10 years. All 4 Ball Joints
for those years carry weight and are pre-loaded to
compensate for wear and dampen steering shocks. |
Cutaway of AAM Lower Ball Joint
from 2005 Dodge Ram 3500 4x4 |
Ball is surrounded by a thin plastic
bushing. There is no preload on ball to dampen
"Death Wobble" or to compensate for normal wear. The
Ball Joint shown here was from a 1 year old truck with
only 5,400 miles on it. The lower Ball Joint was
full of grease, but already slightly loose.
Lower Ball Joints carry all the front
end weight of these vehicles.
Outside diameter of Ball Joint Case
is only 4% larger than that used by older and lighter
4x4's such as the Jeep CJ and Ford Bronco. All 4 ball
Joints on those older vehicles were weight carrying. |
