In order to check for free play in the lower ball joints, you must first
"unload" the joint. You can unload your lower joints only by placing the
jack under the lower control arm, and raising the wheel off the ground,
Then, the only weight on the joint will be the wheel and tire assembly,
along with the upper joint and upper arm. Then, you can place a long bar
under the wheel, and lift the wheel and tire assembly. The total amount of
play is not necessarily just the up and down movement, but more important is
the incidental side-to-side movement that accompanies it. The up-and-down
movement will be obvious, and is the standard measurement used for specs.
When the wheel moves around in the ball socket, the camber, caster, and toe
will change. How much it moves and how quickly it recovers will be the end
result to your driving control. Yes, specifications are given in an exact
figure, and some judgment is expected, but if your movement is greater than
the specs, figure that changing the joints will help.
I disagree that just because you're changing the lowers, you should change
the uppers, too. Usually, when the lower joint is the normally loaded
joint, as the Dakota is, the uppers will last 2 or 3 times longer.
Mike Higgins
1999 Dakota
----- Original Message -----
From: "David Gersic" <info@zaccaria-pinball.com>
To: <dakota-truck@dakota-truck.net>
Sent: Tuesday, November 09, 2010 8:38 PM
Subject: DML: Bad ball joints?
>
> 2001 4x4 Dakota
>
> My front tyres were worn funny, back ones look ok. Got about 27K miles on
> them. So in to the local NTB for some new fronts and an alignment check.
> The
> truck does have a slight pull when driving, so I figure the alignment is
> probably off a little.
>
> Looking at the tyres, the guy says he thinks it's alignment and probably
> the
> shocks are bad. With 120K miles on the truck, and no idea how old the
> shocks
> are, this seems a reasonable diagnosis to me.
>
> I get a call later. The tyres are done, but they can't do the alignment.
> Shocks are bad (no surprise there), but they also want to replace the
> upper
> and lower ball joints because they're bad. I told them to finish the
> tyres,
> hold off on the alignment, and I'll take care of the ball joints and
> shocks
> myself. Later, when I picked it up, I'm told that the lowers are bad, but
> that
> I might as well replace the uppers at the same time (so the uppers are not
> bad?).
>
> Tonight, I pulled the truck in to the garage to have a look. Front wheels
> off,
> visual inspection, nothing looks obviously bad about the ball joints. The
> seals are intact, no damage or signs of grease or anything like that. The
> shocks are, as you'd expect, old and rusty looking.
>
> I checked the FSM for the ball joint testing procedure. I don't have a
> dial
> indicator, but I'm assuming that if the dial indicator were here and
> showing
> 1.5mm or more play in the joint that I'd at least be able to detect some
> play
> in it. Maybe not an exact diagnosis (is 1.4mm ok, but 1.5mm is bad?), but
> at
> least an indication that there's a problem. With the wheels on, pushing in
> all
> directions on them, I can't detect any play in the ball joints. There's
> what
> seems like a little bit of play in the steering rack, pushing and pulling
> on
> the front and back of the tyre, but no play at all pushing and pulling on
> the
> top and bottom.
>
> So now I'm wondering if somebody's trying to snow me here. If the joints
> are
> actually bad, shouldn't there be some perceptible play in them? I don't
> have a
> truck with a known bad one to compare it to.
>
> If they're actually bad, it looks like the upper shouldn't be a big deal.
> One
> castle nut and three bolts to remove it. I've read in the archives that a
> pickle fork will work instead of having to have Mopar's special removal
> tool.
> But looking at the lower, I don't see how that can be removed. At least
> not
> removed in my garage.
>
> NAPA's web site lists a bolt in lower, and a press in lower. I have the
> press
> in lower ball joint. I don't know what the bolt in lower fits, but there's
> nothing on mine to bolt it to. There's nothing in the FSM about actually
> removing the lower ball joint. So does that mean I'd need a whole new
> lower
> arm? Or is this something a shop with a press can remove the ball joint
> and
> press a new one in place?
>
>
This archive was generated by hypermail 2b29 : Wed Dec 01 2010 - 14:08:15 EST