I used the specs from this post over at dodgeram.org and it has worked very well for my truck
First of all let me say this: Damn all of you nice people for
wanting me to stay with aadt
Anyway, I'm not much for having a good short term memory, so bear
with me.
In a previous posting written by ???? (don't remember), they were
complaining about a shimmy in their Ram 4x4 after striking bumps in the
road.
I suggested that the front end alignment has either too little or
too much caster, thus causing a caster shimmy. He did not like my
response and changed his concern from a "shimmy" to a "bounce" (big
difference), and insisted it was the shocks. Maybe it is, I haven't
driven it. He also said the alignment "checked out". Here's the
problem:
Alignment programs (and service manuals I believe), give a wide
acceptable range for front caster on the 4x4 Rams. I believe the range
is 2 degrees to 5 degrees (if that's not correct, it's pretty close).
The problem occurs when the alignment tech (independent or dealer)
tells you that the measurements "checked out fine", just because they
were in this broad range of acceptance.
Caster readings that fall on either end of the scale are subject to
caster shimmy, even though they are "acceptable". I had to align some
30 trucks and attend a 9 hour "Dodge Ram Chassis Dynamics Diagnostics"
training session (fancy name, ehh?), before finding out that 3 degrees
to 4 degrees is the optimal caster setting for 4x4 Rams that eliminates
caster shimmy.
Below I will post what specifications I set Ram trucks to. First
I want to give a little more info on correct Ram alignments so you can
see if you had a job well done,
The eccentrics on the lower control arms ARE NOT for individual
wheel caster adjustments (even though our alignment machine says they
are). The eccentric sleeves in the upper ball joints are for adjusting
individual camber and total cross caster (difference in caster between
two front wheels). This is why replacement eccentrics are positionable
in eight different ways.
Once camber and cross caster are attained with the eccentrics, the
lower control arm eccentrics are then used to swing the caster readings
into specifications. The two eccentrics must be swung in the SAME
direction in EQUAL amounts. If they are not, it will create a setback
condition (one front wheel further forward than the other).
FYI - Comparing between the two front wheels, caster will cause a
pull to the smaller value and camber will cause a pull to the larger
value. A truck set up with caster pulling in one direction and camber
pulling in the other direction, can lead to a wandering truck; even
though it is "in specifications"!!!!!!
If the eccentrics on the lower control arms of your truck are not
pointing the same direction, the alignment was done incorrectly and the
axle was "twisted" or "forced" into position to attain the acceptable
values (seen them from the factory this way, go figure).
A correct alignment will set the truck up with a slight negative
cross caster (truck has slight pull to left) to compensate for right
hand road crown. Camber will be equal side to side slightly on the
negative side. This will help maintain acceptable camber when hauling
heavy loads, as the truck tends to lift in the front when towing.
Camber will then fall slightly positive when towing.
Just because the alignment shop says "it's in specifications", that
does not mean it is set up for proper performance and handling!!!!!!!!!
Specifications (my personal settings for every Ram I align): all specs
below are in degrees.
Left Wheel Right Wheel
-------------- ----------------
Caster 3. 2 3. 5
Cross Caster -. 3
Camber -. 10 -. 10
Cross Camber 0. 0
Toe - standard specs, (maybe a little out if you tow a lot, they will
pull in as the front end lifts up).
Brent
ASE Certified
Gold Certified Chrysler tech
--------------------------------------------------------------------------------
Attention: TDR Forum Junkies 
