I recently replaced upper ball joints on a '96 Dodge 3500 (1-ton) van.
This vehicle uses pressed-in ball joints, and I replaced them with a
standard C-frame tool. After a few months, one of the ball joints
backed itself out (this is a poor design, IMO). I pressed it back in,
and tack-welded it in a few spots. So far, it's holding just fine.
In order to do the weld, I removed the upper A-frame. Of course, I
didn't think to mark it's position (uses no shims, just slotted bolt
holes to adjust caster/camber) until I'd already loosened the bolts and
let things shift.
I'd like to get the truck properly in alignment. If that's not
possible, at least driveably close until I buy new tires and have a
shop fine-tune it.
I think I can measure camber with a plumb bob, and toe-in's a
no-brainer, but how in the devil can I measure caster?
Also, is there an online reference where I can find the alignment specs
for my vehicle?
Go to dodgetalk.com,the ball joint problem is discussed often.Or often
disgusted.I am not certain about the vans but the late 90s trucks are a
real problem.I hope you have a moog and not a dodge ball joint
Fundamentally, Castor is the angle of the "king pin axis" viewed from the
side, while camber is the angle of the wheel viewed from the front. You can
indeed set camber using a plain level and a ruler, I do it all the time on
my race car in fact. Castor is harder. I can think of a couple of fiddles
to get it close, but I'd personally take a truck to an alignment shop and
let them do it.
Fiddles: My race car has a flat machined on the upright so I just put a
digital level on and read the castor directly. You can measure castor
indirectly by measuring it's effect on camber as you turn the wheels,
usually 20 degrees left and right. You could probably get in the ball park
by measuring how far back the upper ball joint is compared to the lower
using your level and a ruler, and compare side to side. You could do it by
adjusting until the truck tracks straight - that has the advantage of
ignoring what the measurement actually is and gets the effect you want.
Turn the wheels full left and right and measure the camber change at each
position. The caster is 1/2 the difference if the wheels had turned to 90
degrees so you have to do some calculation there. Since you have one that
hasn't been changed, you can compare between the two sides and make them
equal. It is more important to have matched caster than an absolute value.
Why isn't there an Ozone Hole at the NORTH Pole?
Are you sure it was a press fit?? Most uppers in chrysler product
trucks & older rear drive cars are screw in. Mabee they changed the
design in the newer ones but if the joint has flat sides around the
top, it's a threaded situation, which would explain it not staying put.
I've welded quite a few of these that were stripped out with long
lasting success but always on the vehicle. The best way to get proper
alignment restored will be at an alignment shop. Good luck.
A lot of people *ruined* old Chrysler upper control arms by ASSuming
they were just like other brands and pressing the screw-in joints out
and new ones in.
However, Chrysler cheaped-out on the trucks in the 90s and did use
Yes, they are definitely pressed in. The holes in the a-frames have
smooth sides, and there are "grip ridges" but no threads on the ball
joints. Some people look at the ball joints and think they are
screw-in because there are flats on the outer portion, but that's
deceptive. You'll quickly get tired of trying to unscrew them :)
It's best to arrive at the shop with alignment in the ballpark.
Caster and camber are highly interactive on this vehicle, ie you loosen
the upper A-frame mounts and wiggle everthing around to change both
settings. If they are 'way off, you're far less likely to get a
satisfactory result from some guy who's used to just setting the
Do you change your own oil? Some of us have curiousity that goes a
little further :)
JR North wrote:
Nice stuff on the site. You obviously practice do-it-yourself, but
somehow didn't want to preach it (at least not to me, unless you were
BTW, the Datsun 2000 roadster has always been one of my favorite cars.
One of my best friends from HS had one and it was fast. I'd think
about selling that little 1600, though .... she obviously likes it in
the rear, and that might get you killed one of these days :)
JR North wrote:
I have had shops do front end alignments for me and I get the car home
and end up redoing them in my carport with a tape and string and a
level. I have yet to find a front end shop that know's how to read specs.
If the tire's contact patch is BEHIND the point where the "kingpin
axis" would be projected onto the pavement, is this positive or
Since I (luckily) have one side where the caster/camber is presumably
correct, can I fine-tune the match using driving characteristics? In
other words, if the vehicle pulls/drifts to the driver's side, which
side needs positive caster reduced (assuming equal camber and level
OK, I did the homebrew alignment last night, after also replacing two
idler arms and putting the best two tires on front. BTW, thank-you Dan
Saitz for emailing to me the alignment specs for my van!
First, I used my 4' box-beam level to locate a level parking lot. Had
to go to a church about a block from the house. On the way home, I
took the van up to about 50 MPH on several smooth roads. It pulled
very strongly to the left, and I thought I could hear some scrubbing
from the tires.
On the driveway at home, I removed the right front wheel and loosened
the two mounting bolts on the upper A-frame. These bolts ride in
slotted holes in the vehicle frame, so that the front and rear mounting
points can be separately adjusted by pulling/pushing toward or away
from the vehicle centerline. So, you adjust caster and camber
I pulled the upper A-frame all the way to the outside stops. This
would result in maximum positive camber (top of tire leaning outward)
and an unknown (but hopefully small) amount of caster. Then I slightly
snugged the front A-frame bolt to hold it in place, and pushed the rear
mount toward the vehicle centerline by a "calibrated eyeball" amount to
increase the caster. Then I slightly snugged the rear bolt, loosened
the front bolt, and pushed the front mount of the A-frame toward the
centerline by HALF of the "calibrated eyeball" amount. My idea here
was to achieve a net reduction from max camber while preserving half of
the added caster.
I then repeated the procedure on the left side, re-installed the
wheels, grabbed a flashlight, and headed to my level parking lot for
some measurements. I noticed an immediate improvement in handling.
The pulling seemed to be gone, though it was hard to tell at 30 MPH on
bad roads. There did seem to be a lot of "wandering", though.
With the help of my girlfriend, I made camber measurements straight
forward and turning to the stops (maybe around 45 degrees) on both
sides. By having her steady the vertical 4' level against the fender
while I used the flashlight to watch the bubble and scoot the other end
around on the ground, we were able to come up with a reference that was
"plumb" (at least in the plane perpendicular to the vehicle) and within
about two inches of the wheel. I made distance measurements from the
vertical to the rim at top and bottom, to calculate actual camber.
I calculated camber of +1.6 degrees on the right and +1.2 degrees on
the left. The tops of my tires were still leaning slightly "out".
The caster calculations were more problematic because of measurement
uncertainty. When the wheel was turned, this resulted in fender
obscuration of the point where I wanted to set the level. So, this
measurement distance was several inches further away, probably adding
error. I was, however, consistent in seeing a decrease in positive
camber (top of wheel tilting relatively inward) of both wheels when
they were on the outside of a turn. This decrease was "maybe" 0.6
degree on one side and 1.0 degree on the other side. So, I felt I at
least had achieved positive caster. Everyone says that caster is a
handling factor but not a wear factor, so I figured I'd fine-tune this
by road testing.
Next we took several toe-in measurements, and found the wheels to be
toed out by about 1/4".
I drove back home (tools and jack were still on the driveway). I
adjusted the toe to zero by shortening the tie rod on the left side
(remembering the earlier drastic left pull, I was thinking about
centering the steering wheel).
Time for a road test - and the van drove like a dream. No pull, all
the way to 65 MPH, and the wandering (probably due to the toe-out) was
also gone. You could take your hands off the wheel and it went
perfectly straight. And, the wheel was centered.
Then I made a mistake. Thinking about the tire wear due to the excess
positive camber, particularly on the right, I decided to make a small
change and take another measurement. Since decreasing right camber
would supposedly make the vehicle pull a little to the left, I thought
I'd simultaneously decrease the caster on that same wheel (several
references indicate that a vehicle pulls to the side with increased
camber or decreased caster) to compensate.
Well, that was just too many variables to deal with when it's after
midnight and the upper A-frame is free to move in two dimensions at
once. My next road test had the vehicle drifting noticeably to the
left. You just can't make a small, precise, "delta" change without
some sort of fixed reference or simultaneous measurement.
Anyway, it took another round of wrenching (and was about 1:15 am)
before I had the driveability back to where I was satisfied.
This weekend I'll try another idea for fine-tuning the camber, which is
still excessive by anyone's account. I'll use a magnetic-base stand
from a dial indicator to position a pointer directly above the grease
fitting of the upper ball joint. That way, I will be able to tell
exactly how much relative shift I've made in the A-frame before
re-tightening the bolts.
Yes, it was a lot of work, but I really feel good about the learning
The pointer and magnetic base trick worked perfectly. I took
measurements, removed the wheel, installed the pointer, and then made
the necessary relative adjustments. The van drives perfectly, no
pulling, no wander, etc. I'm not even going to take it to a shop for
any fine-tuning, as there's no way they could improve on the
driveability, and the current settings should minimize tire wear.
I'd recommend this method to anyone who wants to try a do-it-yourself
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