Re: Why does the (steering) wheel wobble?

[Eric Maxon <emaxon@megsinet.net>]

Andrew Finney wrote:

> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> The patient in this case is a '86 4kcsq with 158k mi.
>
> The symptom is a shimmy or oscillation in the steering wheel
> noticable
> only when in the process of turning the wheel, and from about
> 5 to 40
> mph.  The oscillation frequency changes with speed (so it isn't
> the
> rack, I guess) and above 40 mph is high enough to not be
> noticed.  Tires
> have been balanced and rotated front to back, symptoms
> remain unchanged.
>
> Is this a CV joint going South?  Anything else come to mind?
>

Unlikely-- unless you've got a broken ball cage in an outer joint,
there's little chance of a bad CV joint causing the steering wheel to
oscillate, and if you did have a broken cage, you'd hear LOUD clacking
comming from the joint on hard turns.

Amen to Andrew Finney-- definately check the outer tie rod ends for
play.  Also, don't rule out the rack-- here's how to check it:  turn the
wheel all the way to the left to move the tie rod carrier bracket far
enough over to grab.  Stick your arm either under the master
cylinder/brake booster or between the ps resevoir and ignition coil and
grab the bracket.  Try to ROTATE the bracket in both directions.  if it
rotates AT ALL, the rack is shot.  Unfortunately, the rack is round on a
4000 w/ ps, and increasing the tension of the rack against the pinion
(requires adding a shim behind the spring loaded tensioner... I used a
nickel!) will not help eliminate this sort of play.  (On a 5000, the
rack is square in cross section, and is pressed against the pinion by a
spring loaded notched cylinder-- increasing the spring tension sometimes
helps stop the rack from rotating within the housing.  Can't be done w/
the 4000 rack-- I JUST tried it on an '84 4000sq here and no dice.)  If
the rack can rotate within the housing, then the toe in will vary
unpredictably in response to cornering, acceleration, deceleration, you
name it.  Even with new control arm bushings, ball joints, tie rods,
brake rotors, wheel bearings, the whole sheebang, you'll never get rid
of the shimmy if the rack rotates.


> While I have your rapt attention, Is there anything else I should
> likely be replacing on this car to return it to or improve upon it's
> original reliability or performance.  Other than maintenance
> items the
> only things I have done to this car are:  Timing belt and water
> pump,
> front lower ball joints, mufflers, thermal switch, and alternator.

Cooling system service-- check the thermostat, flush the system with the
thermostat removed, fill with Sierra phosphate free coolant.  FI
service-- clean the injectors and replace the o-rings.  Hunt for
deteriorating vaccuum lines and replace any you find.  Clean the intake
ducts and air metering unit.  Put Redline MTL in the gearbox-- pronto.
(You'll need 3 quarts.)  Check your CV joint boots-- take care of any
torn boots immediately to avoid more costly replacement of the joints
themselves.  Put an appropriate amperage inline fuse in the radiator
fan's power wire, right at the fan-- the fuse is often on the coil side
of the fan relay, and will not protect the circuit if the fan blows
shorted.

Happy motoring.

Eric.



> TIA,
> Eric Rayl
> ericrayl@nameless.com
>
> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>
> It could be one or both of the tie rod ends. Given enough play
> the wheel housing will move in and out slightly producing a
> vibration or slight jerking in the steering wheel.
>
> Andrew Finney
> 1983 UrQ.