Jeep Front End Question/ 2000 JGC + Bonus Question!!

This is a 2000 Jeep Grand Cherokee, 130,000 miles.

The sympton is just a bit hard to describe. When I am driving on a rocky,
gravel road, I feel a shaking in my steering column. It is very
weird....... if the road is very rutty, I can only assume that something
in the front end is worn and loose, and this sets up a shimmy that I
actually feel quite strongly in my steering column and steering wheel. It
seems that I can actually "hear" rattling in my steering column.

This is NOT death wobble. I have no such symptons at any speed, on a
smooth or even semi smooth road. It is only there when I travel up and down
our very rutty gravel mountain road, and I feel it even at very slow speeds.

The "jerking" steering column is quite pronounced.

I am thinking of tie rod ends............ or steering stabilizer , or ball
joints ??


What is the most likely culprit?


BONUS QUESTION-- not related to above primary question..... I have a
low frequency, rumble type rattle underneath my car. It sounds like it
comes from the center of the car, toward the back 1/2 of the car. Of
course, I can't be sure. It sounded so much to me like part of the exhaust
system, I had my mechanic put in on the rack and check all of that very
carefully. He could find nothing loose. I only hear this when I am going
over rough roads, with many bumps etc. It is not a high pitch rattle... it
is more like a rumble.

What other parts could I suspect, and inspect to locate this noise. Could a
defective wheel bearing exhibit this noise? How does one check the status
of a wheel bearing ?

Thank you all very much !!!!

--James--

Hi James,
It may be any of the parts you mentioned, but it can't shimmy
without a bad steering dampener.
God Bless America, Bill O|||||||O
http://www.billhughes.com/

James wrote:
>
> This is a 2000 Jeep Grand Cherokee, 130,000 miles.
>
> The sympton is just a bit hard to describe. When I am driving on a rocky,
> gravel road, I feel a shaking in my steering column. It is very
> weird....... if the road is very rutty, I can only assume that something
> in the front end is worn and loose, and this sets up a shimmy that I
> actually feel quite strongly in my steering column and steering wheel. It
> seems that I can actually "hear" rattling in my steering column.
>
> This is NOT death wobble. I have no such symptons at any speed, on a
> smooth or even semi smooth road. It is only there when I travel up and down
> our very rutty gravel mountain road, and I feel it even at very slow speeds.
>
> The "jerking" steering column is quite pronounced.
>
> I am thinking of tie rod ends............ or steering stabilizer , or ball
> joints ??
>
> What is the most likely culprit?
>
> BONUS QUESTION-- not related to above primary question..... I have a
> low frequency, rumble type rattle underneath my car. It sounds like it
> comes from the center of the car, toward the back 1/2 of the car. Of
> course, I can't be sure. It sounded so much to me like part of the exhaust
> system, I had my mechanic put in on the rack and check all of that very
> carefully. He could find nothing loose. I only hear this when I am going
> over rough roads, with many bumps etc. It is not a high pitch rattle... it
> is more like a rumble.
>
> What other parts could I suspect, and inspect to locate this noise. Could a
> defective wheel bearing exhibit this noise? How does one check the status
> of a wheel bearing ?
>
> Thank you all very much !!!!
>
> --James--

Vehicle vibration can be caused by:
² Tire/wheel unbalance or excessive runout
² Defective tires with extreme tread wear
² Nylon overlay flat spots (performance tires only)
² Incorrect wheel bearing adjustment (if applicable)
² Loose or worn suspension/steering components
² Certain tire tread patterns
² Incorrect drive shaft angles or excessive drive
shaft/yoke runout
² Defective or worn U-joints
² Excessive brake rotor or drum runout
² Loose engine or transmission supports/mounts
² And by engine operated accessories
Refer to the appropriate Groups in this manual
for additional information.

VIBRATION TYPES
There are two types of vehicle vibration:
² Mechanical
² Audible.
Mechanical vehicle vibration can be felt through
the seats, floor pan and/or steering wheel.
Audible vehicle vibration is heard above normal
background noise. The sound can be a droning or
drumming noise.
Vibrations are sensitive to change in engine torque,
vehicle speed or engine speed.

ENGINE TORQUE SENSITIVE VIBRATION
This vibration can be increased or decreased by:
² Accelerating
² Decelerating
² Coasting
² Maintaining a constant vehicle speed

VEHICLE SPEED SENSITIVE VIBRATION
This vibration condition always occurs at the same
vehicle speed regardless of engine torque or engine
speed.

ENGINE SPEED (RPM) SENSITIVE VIBRATION
This vibration occurs at varying engine speeds. It
can be isolated by increasing or decreasing the engine
speed with the transmission in NEUTRAL position.

VIBRATION DIAGNOSIS
A vibration diagnosis should always begin with a
10 mile (16 km) trip (to warm the vehicle and tires).
Then a road test to identify the vibration. Corrective
action should not be attempted until the vibration
type has been identified via a road test.
During the road test, drive the vehicle on a smooth
surface. If vibration exists, note and record the following
information:
² Identify the vehicle speed range when the vibration
occurs
² Identify the type of vibration
² Identify the vibration sensitivity
² Determine if the vibration is affected by changes
in vehicle speed, engine speed and engine torque.
When the vibration has been identified, refer to the
Vibration Diagnosis chart for causes. (see below)Consider correcting
only those causes coded in the chart that are
related to the vibration condition.
Refer to the following cause codes and descriptions
for explanations when referring to the chart.

http://i112.photobucket.com/albums/n...Vibrations.jpg



TRR-Tire and Wheel Radial Runout: Vehicle
speed sensitive, mechanical vibration. The runout
will not cause vibration below 20 mph (32 km/h).
WH-Wheel Hop: Vehicle speed sensitive, mechanical
vibration. The wheel hop generates rapid
up-down movement in the steering wheel. The vibration
is most noticeable in the 20 - 40 mph (32 - 64
km/h) range. The wheel hop will not cause vibration
below 20 mph (32 km/h). Wheel hop is caused by a
tire/wheel that has a radial runout of more than
0.045 of-an-inch (1.14 mm). If wheel runout is acceptable
and combined runout cannot be reduced by repositioning
the tire on wheel, replace tire.
TB-Tire/Wheel Balance: Vehicle speed sensitive,
mechanical vibration. Static tire/wheel unbalance
will not cause vibration below 30 mph (46 km/h). Dynamic
tire/wheel unbalance will not cause vibration
below 40 mph (64 km/h).
TLR-Tire/Wheel Lateral runout: Vehicle speed
sensitive, mechanical vibration. The runout will not
cause vibration below 50 - 55 mph (80 - 88 km/h). Excessive
lateral runout will also cause front-end
shimmy.
TW-Tire Wear: Vehicle speed sensitive, audible
vibration. Abnormal tire wear causes small vibration
in the 30 - 55 mph (88 km/h) range. This will produce
a whine noise at high speed. The whine will
change to a growl noise when the speed is reduced.
W-Tire Waddle: Vehicle speed sensitive, mechanical
vibration. Irregular tire uniformity can cause
side-to-side motion during speeds up to 15 mph (24
km/h). If the motion is excessive, identify the defective
tire and replace it.
UAJ-Universal Joint (Drive Shaft) Angles:
Torque/vehicle speed sensitive, mechanical/audible vibration.
Incorrect drive shaft angles cause mechanical
vibration below 20 mph (32 km/h) and in the 70
mph (112 km/h) range. The incorrect angles can also
produce an audible vibration in the 20 - 50 mph (32 -
80 km/h) range. Caster adjustment could be required
to correct the angles.
UJ-Universal Joints: Engine torque/vehicle
speed sensitive, mechanical/audible vibration. If the U-joint is worn it
will cause vibration with almost
any vehicle speed/engine torque condition.
DSY-Drive Shaft and Yokes: Vehicle speed sensitive,
mechanical/audible vibration. The condition
will not cause vibration below 35 mph (56 km/h). Excessive
runout, unbalance or dents and bends in the
shaft will cause the vibration. Identify the actual
cause and repair/replace as necessary.
WB-Wheel Bearings: Vehicle speed sensitive,
mechanical/audible vibration. Loose wheel bearings
cause shimmy-like vibration at 35 mph (56 km/h)
and above. Worn bearings will also produce a growl
noise at low vehicle speed and a whine noise at high
vehicle speed. The wheel bearings must be adjusted
or replaced, as applicable.
AN-Axle Noise: Engine torque/vehicle speed sensitive,
mechanical/audible vibration. The axle will not
cause mechanical vibration unless the axle shaft is
bent. Worn or damaged axle pinion shaft or differential
gears and bearings will cause noise. Replace the
defective component(s) as necessary.
SSC-Suspension and Steering Components:
Vehicle speed sensitive, mechanical vibration. Worn
suspension/steering components can cause mechanical
vibration at speeds above 20 mph (32 km/h).
Identify and repair or replace the defective component(
s).
EA-Engine Driven Accessories: Engine speed
sensitive, mechanical/audible vibration. Vibration can
be caused by loose or broken A/C compressor, PS
pump, water pump, generator or brackets, etc. Usually
more noticeable when the transmission is shifted
into the NEUTRAL position and the engine speed
(rpm) increased. Inspect the engine driven accessories
in the engine compartment. Repair/replace as
necessary.
ADB-Accessory Drive Belts: Engine speed sensitive,
audible vibration. Worn drive belts can cause a
vibration that produces either a droning, fluttering or
rumbling noise. Inspect the drive belt(s) and tighten/
replace as necessary.
DEM-Damaged Engine or Transmission Support
Mounts: Engine speed sensitive, mechanical/
audible vibration. If a support mount is worn, noise
or vibration will occur. Inspect the support mounts
and repair/replace as necessary.
ES-Exhaust System: Engine speed sensitive,
mechanical/audible vibration. If loose exhaust components
contact the vehicle body they will cause noise
and vibration. Inspect the exhaust system for loose,
broken and mis-aligned components and repair/replace
as necessary.


"L.W.(Bill) Hughes III" > wrote in message
...
> Hi James,
> It may be any of the parts you mentioned, but it can't shimmy
> without a bad steering dampener.
> God Bless America, Bill O|||||||O
> http://www.billhughes.com/
>
> James wrote:
>>
>> This is a 2000 Jeep Grand Cherokee, 130,000 miles.
>>
>> The sympton is just a bit hard to describe. When I am driving on a
>> rocky,
>> gravel road, I feel a shaking in my steering column. It is very
>> weird....... if the road is very rutty, I can only assume that
>> something
>> in the front end is worn and loose, and this sets up a shimmy that I
>> actually feel quite strongly in my steering column and steering wheel.
>> It
>> seems that I can actually "hear" rattling in my steering column.
>>
>> This is NOT death wobble. I have no such symptons at any speed, on a
>> smooth or even semi smooth road. It is only there when I travel up and
>> down
>> our very rutty gravel mountain road, and I feel it even at very slow
>> speeds.
>>
>> The "jerking" steering column is quite pronounced.
>>
>> I am thinking of tie rod ends............ or steering stabilizer , or
>> ball
>> joints ??
>>
>> What is the most likely culprit?
>>
>> BONUS QUESTION-- not related to above primary question..... I have a
>> low frequency, rumble type rattle underneath my car. It sounds like it
>> comes from the center of the car, toward the back 1/2 of the car. Of
>> course, I can't be sure. It sounded so much to me like part of the
>> exhaust
>> system, I had my mechanic put in on the rack and check all of that very
>> carefully. He could find nothing loose. I only hear this when I am
>> going
>> over rough roads, with many bumps etc. It is not a high pitch rattle...
>> it
>> is more like a rumble.
>>
>> What other parts could I suspect, and inspect to locate this noise.
>> Could a
>> defective wheel bearing exhibit this noise? How does one check the
>> status
>> of a wheel bearing ?
>>
>> Thank you all very much !!!!
>>
>> --James--

² And by engine operated accessories




Yes, Billy Ray, I think this one of the 50,987 reasons for vibration must
be the one that makes my steering column rattle when I go over a rough road.


Just how did you figure this one out ??

I guess the engine operated accessories are not adversely affected by high
speeds on smooth roads, but that is how they are.

Thanks !!!



--James--

Re the jerking steering - have you checked the box is bolted on tight ?

Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ

"L.W.(Bill) Hughes III" > wrote in message
...
> Hi James,
> It may be any of the parts you mentioned, but it can't shimmy
> without a bad steering dampener.
> God Bless America, Bill O|||||||O
> http://www.billhughes.com/
>
> James wrote:
> >
> > This is a 2000 Jeep Grand Cherokee, 130,000 miles.
> >
> > The sympton is just a bit hard to describe. When I am driving on a
rocky,
> > gravel road, I feel a shaking in my steering column. It is very
> > weird....... if the road is very rutty, I can only assume that
something
> > in the front end is worn and loose, and this sets up a shimmy that I
> > actually feel quite strongly in my steering column and steering wheel.
It
> > seems that I can actually "hear" rattling in my steering column.
> >
> > This is NOT death wobble. I have no such symptons at any speed, on a
> > smooth or even semi smooth road. It is only there when I travel up and
down
> > our very rutty gravel mountain road, and I feel it even at very slow
speeds.
> >
> > The "jerking" steering column is quite pronounced.
> >
> > I am thinking of tie rod ends............ or steering stabilizer , or
ball
> > joints ??
> >
> > What is the most likely culprit?
> >
> > BONUS QUESTION-- not related to above primary question..... I have
a
> > low frequency, rumble type rattle underneath my car. It sounds like it
> > comes from the center of the car, toward the back 1/2 of the car. Of
> > course, I can't be sure. It sounded so much to me like part of the
exhaust
> > system, I had my mechanic put in on the rack and check all of that very
> > carefully. He could find nothing loose. I only hear this when I am
going
> > over rough roads, with many bumps etc. It is not a high pitch rattle...
it
> > is more like a rumble.
> >
> > What other parts could I suspect, and inspect to locate this noise.
Could a
> > defective wheel bearing exhibit this noise? How does one check the
status
> > of a wheel bearing ?
> >
> > Thank you all very much !!!!
> >
> > --James--

I had a noise similar to the bonus question. It turned out to be shock
absorbers. When did you last change them? My 2000 has about the same
number of miles on it.

Reach under the front tire and grab the shock tube and give it a yank. You
might hear the rattle sound.

In any case, I doubt that the factory shocks last 130K.

Paul Nelson


in article , James at
wrote on 10/31/06 6:31 PM:

> BONUS QUESTION-- not related to above primary question..... I have a
> low frequency, rumble type rattle underneath my car. It sounds like it
> comes from the center of the car, toward the back 1/2 of the car. Of
> course, I can't be sure. It sounded so much to me like part of the exhaust
> system, I had my mechanic put in on the rack and check all of that very
> carefully. He could find nothing loose. I only hear this when I am going
> over rough roads, with many bumps etc. It is not a high pitch rattle... it
> is more like a rumble.
>
> What other parts could I suspect, and inspect to locate this noise. Could a
> defective wheel bearing exhibit this noise? How does one check the status
> of a wheel bearing ?
>
> Thank you all very much !!!!
>
> --James--
>
>

Bad steering dampers don't cause shimmy. Good ones just mask the real cause.

I'm guessing he's got a worn or loose track bar. 2000 GC has the solid axle
up front, right?

The rear rumble could be just road noise, does it change in pitch with
vehicle speed, or does it stay on a constant pitch? center rear of the car
could be rear diff. Check your driveshaft U joints for wear, have your diff
inspected.

"L.W.(Bill) Hughes III" > wrote in message
...
> Hi James,
> It may be any of the parts you mentioned, but it can't shimmy
> without a bad steering dampener.
> God Bless America, Bill O|||||||O
> http://www.billhughes.com/
>
> James wrote:
>>
>> This is a 2000 Jeep Grand Cherokee, 130,000 miles.
>>
>> The sympton is just a bit hard to describe. When I am driving on a
>> rocky,
>> gravel road, I feel a shaking in my steering column. It is very
>> weird....... if the road is very rutty, I can only assume that
>> something
>> in the front end is worn and loose, and this sets up a shimmy that I
>> actually feel quite strongly in my steering column and steering wheel.
>> It
>> seems that I can actually "hear" rattling in my steering column.
>>
>> This is NOT death wobble. I have no such symptons at any speed, on a
>> smooth or even semi smooth road. It is only there when I travel up and
>> down
>> our very rutty gravel mountain road, and I feel it even at very slow
>> speeds.
>>
>> The "jerking" steering column is quite pronounced.
>>
>> I am thinking of tie rod ends............ or steering stabilizer , or
>> ball
>> joints ??
>>
>> What is the most likely culprit?
>>
>> BONUS QUESTION-- not related to above primary question..... I have a
>> low frequency, rumble type rattle underneath my car. It sounds like it
>> comes from the center of the car, toward the back 1/2 of the car. Of
>> course, I can't be sure. It sounded so much to me like part of the
>> exhaust
>> system, I had my mechanic put in on the rack and check all of that very
>> carefully. He could find nothing loose. I only hear this when I am
>> going
>> over rough roads, with many bumps etc. It is not a high pitch rattle...
>> it
>> is more like a rumble.
>>
>> What other parts could I suspect, and inspect to locate this noise.
>> Could a
>> defective wheel bearing exhibit this noise? How does one check the
>> status
>> of a wheel bearing ?
>>
>> Thank you all very much !!!!
>>
>> --James--

Actually a bad dampener with air in place of the fluid that has
leaked out will bounce like a rubber ball.
God Bless America, Bill O|||||||O
http://www.billhughes.com/

Matt Macchiarolo wrote:
>
> Bad steering dampers don't cause shimmy. Good ones just mask the real cause.

Only if the front end is shimmying already. Otherwise it would do nothing.

"L.W.(Bill) Hughes III" > wrote in message
...
> Actually a bad dampener with air in place of the fluid that has
> leaked out will bounce like a rubber ball.
> God Bless America, Bill O|||||||O
> http://www.billhughes.com/
>
> Matt Macchiarolo wrote:
>>
>> Bad steering dampers don't cause shimmy. Good ones just mask the real
>> cause.

Dave, I will have the steering box checked to make sure it is tight.

To Paul, I had the shocks replaced about 15k miles ago.

Thanks to both !

--james--