"Clunk", my hub?

I'm driving a '97 Explorer. When driving up a slight rise at 40+, I'm
hearing a "clunk" from underneath. Can occur several times climbing
the hill. Like one rotating piece of metal catching up with another.
Brought it to a mechanic to diagnosis the problem and he said it was
probably something wrong with "the hubs". GOOGLING for hubs, I see
several articles describing how to disassemble, clean, lube and
re-assemble, but before doing that, I was wonder if the symptoms I'm
describing could indeed be wheel hub problems. Do these symptoms sound
familiar? - Mike

"Michael Horowitz" > wrote in message
...
> I'm driving a '97 Explorer. When driving up a slight rise at 40+, I'm
> hearing a "clunk" from underneath. Can occur several times climbing
> the hill. Like one rotating piece of metal catching up with another.
> Brought it to a mechanic to diagnosis the problem and he said it was
> probably something wrong with "the hubs". GOOGLING for hubs, I see
> several articles describing how to disassemble, clean, lube and
> re-assemble, but before doing that, I was wonder if the symptoms I'm
> describing could indeed be wheel hub problems. Do these symptoms sound
> familiar? - Mike

My experiences with bad hubs on the earlier Exporers ('91 and '92) was they
would clunk while turning, not while going straight. No problems yet with
the hubs on my '97. I have read of problems with the transfer case fully
engaging the front wheels due to a dirty sensor in the case and/or uneven
tire wear.

At least we can be pretty sure it's not bad radius arm bushings ;-)

On Fri, 25 May 2007 16:01:52 -0700, "Ulysses"
> wrote:

.. I have read of problems with the transfer case fully
>engaging the front wheels due to a dirty sensor in the case and/or uneven
>tire wear.
>
I have an interesting coincidence to report. Just today I ordered an
OBC II reader. How would a dirty sensor be represented? - Mike

Michael Horowitz wrote:
> I'm driving a '97 Explorer. When driving up a slight rise at 40+, I'm
> hearing a "clunk" from underneath. Can occur several times climbing
> the hill. Like one rotating piece of metal catching up with another.
> Brought it to a mechanic to diagnosis the problem and he said it was
> probably something wrong with "the hubs". GOOGLING for hubs, I see
> several articles describing how to disassemble, clean, lube and
> re-assemble, but before doing that, I was wonder if the symptoms I'm
> describing could indeed be wheel hub problems. Do these symptoms sound
> familiar? - Mike


97's do not have engagable hubs as far as I know, they have a vaccume
engaged coupling one side of the front axle. Check u-joints first.
Jack

On Sat, 26 May 2007 01:44:48 -0400, jrchilds >
wrote:

>97's do not have engagable hubs as far as I know, they have a vaccume
>engaged coupling one side of the front axle. Check u-joints first.
> Jack

Jack - I see elsewhere Dr. Bob's explaination on how to replace
U-joints. What is the test to determine if indeed it's the U-Joints
that are causing my 'clunk'? - Mike

Michael Horowitz wrote:
> On Sat, 26 May 2007 01:44:48 -0400, jrchilds >
> wrote:
>
>> 97's do not have engagable hubs as far as I know, they have a vaccume
>> engaged coupling one side of the front axle. Check u-joints first.
>> Jack
>
> Jack - I see elsewhere Dr. Bob's explaination on how to replace
> U-joints. What is the test to determine if indeed it's the U-Joints
> that are causing my 'clunk'? - Mike
>

Easy way is to jack up one rear wheel and with the car in park try to
turn it. If you feel /see a clunk when the driveshaft stops.
Or just crawl under the car and try to turn the driveshaft, if it moves,
replace the u-joints.
Jack

On Sat, 26 May 2007 12:00:30 -0400, jrchilds >
wrote:


>Easy way is to jack up one rear wheel and with the car in park try to
>turn it. If you feel /see a clunk when the driveshaft stops.
>Or just crawl under the car and try to turn the driveshaft, if it moves,
>replace the u-joints.
>Jack

Jack - Forgive me for not knowing the correct terms but that will
improve shortly - I ordered the Service Manual and it will be in later
this week. Tracking the torque backwards from the front wheels: two
wheel axles meet at what could be described as a differential (but in
the front), power is provided by a 3-4' drive shaft which connects
this front 'differential' to the transmission. I assume a U-Joint
where this drive shaft meet the transmission. When I hold the
dome-shaped thing into which the U-joint is inserted and turn the
drive shaft, I get play; not so at the front end, which is very
obviously a U-joint.
Am I correct in assuming there should be no play and that the joint
that needs replacing?

If someone can tell me the correct termanology for what I intend to
do, I'll GOOGLE for the repair procedure - Mike

Michael Horowitz wrote:
> On Sat, 26 May 2007 12:00:30 -0400, jrchilds >
> wrote:
>
>
>> Easy way is to jack up one rear wheel and with the car in park try to
>> turn it. If you feel /see a clunk when the driveshaft stops.
>> Or just crawl under the car and try to turn the driveshaft, if it moves,
>> replace the u-joints.
>> Jack
>
> Jack - Forgive me for not knowing the correct terms but that will
> improve shortly - I ordered the Service Manual and it will be in later
> this week. Tracking the torque backwards from the front wheels: two
> wheel axles meet at what could be described as a differential (but in
> the front), power is provided by a 3-4' drive shaft which connects
> this front 'differential' to the transmission. I assume a U-Joint
> where this drive shaft meet the transmission. When I hold the
> dome-shaped thing into which the U-joint is inserted and turn the
> drive shaft, I get play; not so at the front end, which is very
> obviously a U-joint.
> Am I correct in assuming there should be no play and that the joint
> that needs replacing?
>
> If someone can tell me the correct termanology for what I intend to
> do, I'll GOOGLE for the repair procedure - Mike


You seem to get it, there are 2 u-joints, one on each end of the
driveshaft, plus a cv(constant velocity)joint in the middle of it.
To check them, put the explorer in 4 wheel low, turn off the engine and
check for free play. The manual is a very good idea, got mine from e-bay
for 9.00$ from ebay on cdrom. In 2 wheel high, the driveshaft should
spin freely.

On Mon, 28 May 2007 13:56:53 -0400, jrchilds >
wrote:

> The manual is a very good idea, got mine from e-bay
>for 9.00$ from ebay on cdrom.

Wow. Mine cost $160.
When you say driveshaft we're both talking about to forward one, not
the one that powers the rear wheels - Just checking.
Let me GOOGLE for "constant velocity joint"; I may have another
question.- Mike

On Mon, 28 May 2007 13:56:53 -0400, jrchilds >
wrote:


>
>You seem to get it, there are 2 u-joints, one on each end of the
>driveshaft, plus a cv(constant velocity)joint in the middle of it.
>
Hmmmm. We may have a disconnect. It appears the CV joints are on the
forward axles. What I"m describing is the joint that fits into what I
believe is the transfer case; a 'box' that is attached to the side of
the xmission. - Mike