GMC front wheel assebmly "clunk

thomas g. warner

New member
Mar 24, 1998
1,863
0
0
If you can't feel any play in the wheel when it is off the ground it can't
be in the bearings, knuckles or huubs. My guess is a shock absorber shaft
broken or nut loose, or snap ring on the outer CV joint. Axel could be
shifting back and forth on the inside when you raise and lower it. Raise it
back up and grab the axel from the inside and see if you can pull it away
from or towards the wheel. Loing shot is inner CV joint. Did this mechanic
that used the air wrench service either of these assemblies?

>OK, doctors, , here's the latest set of symptoms. Hope some one has
>a diagnosis.
>
>1. When lowering to the ground the jacked up right front wheel on my
>Transmode, I heard a clunk and felt the wheel shift inwards as it
>settled to the ground and supported the weight of the coach on that
>side.
>
>2. I jacked the coach back up and with the wheel off the ground I
>grabbed it at the 12:00 and 6:00 o'clock postions and gave it a tug. To
>my chagrin there was about a 1/2 inch in and out movement in the wheel.
>
>3. Now the bearings, hub, lower ball joint and drive axle on that side
>were all replaced last year and about 10,000 miles ago.
>
>4. Recalling Patrick's recent account of discovering the axle nut
>"finger tight" on one of his wheels, I checked the nut on mine, and low
>and behold, it too was loose. The cotter pin was in place but I
>remember seeing the mechanic use a air wrench to torque the nut on the
>axle last year.
>
>5. I retorqued the nut to about 200 ft-lbs with the wheel on the ground.
>This took all the play out of the wheel that I had before. Thank
>goodness.
>
>6. However (there's always a 'however') the "clunk" is just as bad as
>before. It sounds like something is shifting in position relative to
>another part when enough weight is in play as the supporting bottle jack
>retracts.
>
>7. I can see or feel no movement in the ball joints (top and bottom),
>the control arms, sway bar, or wheel.
>
>Is it possible for the wheel bearings to be shifting? How would I tell?
>What would cause the axle nut to come loose?
>
>Ah, this GMC is a puzzle.
>
>Thanks,
>Phil Stewart
>
>
 
OK, doctors, , here's the latest set of symptoms. Hope some one has
a diagnosis.

1. When lowering to the ground the jacked up right front wheel on my
Transmode, I heard a clunk and felt the wheel shift inwards as it
settled to the ground and supported the weight of the coach on that
side.

2. I jacked the coach back up and with the wheel off the ground I
grabbed it at the 12:00 and 6:00 o'clock postions and gave it a tug. To
my chagrin there was about a 1/2 inch in and out movement in the wheel.

3. Now the bearings, hub, lower ball joint and drive axle on that side
were all replaced last year and about 10,000 miles ago.

4. Recalling Patrick's recent account of discovering the axle nut
"finger tight" on one of his wheels, I checked the nut on mine, and low
and behold, it too was loose. The cotter pin was in place but I
remember seeing the mechanic use a air wrench to torque the nut on the
axle last year.

5. I retorqued the nut to about 200 ft-lbs with the wheel on the ground.
This took all the play out of the wheel that I had before. Thank
goodness.

6. However (there's always a 'however') the "clunk" is just as bad as
before. It sounds like something is shifting in position relative to
another part when enough weight is in play as the supporting bottle jack
retracts.

7. I can see or feel no movement in the ball joints (top and bottom),
the control arms, sway bar, or wheel.

Is it possible for the wheel bearings to be shifting? How would I tell?
What would cause the axle nut to come loose?

Ah, this GMC is a puzzle.

Thanks,
Phil Stewart
 
FWTW -- a "good" mechanic will not use an air gun to tighten any bolt
without a torque wrench follow-up. If your guy just zaps your bolts on,
including lug nuts (a)throw a torque wrench on then (b)find a new guy.
In some states it is illegal to torque wheels with air gun and no torque
stick.

> -----Original Message-----
> From: owner-gmcmotorhome
> [mailto:owner-gmcmotorhome]On Behalf Of Thomas G.
> Warner
> Sent: Wednesday, July 15, 1998 11:12 PM
> To: gmcmotorhome
> Subject: Re: GMC: GMC front wheel assebmly "clunk"
>
>
> If you can't feel any play in the wheel when it is off the ground it can't
> be in the bearings, knuckles or huubs. My guess is a shock absorber shaft
> broken or nut loose, or snap ring on the outer CV joint. Axel could be
> shifting back and forth on the inside when you raise and lower
> it. Raise it
> back up and grab the axel from the inside and see if you can pull it away
> from or towards the wheel. Loing shot is inner CV joint. Did
> this mechanic
> that used the air wrench service either of these assemblies?
>
>
>
>
>

> >OK, doctors, , here's the latest set of symptoms. Hope some one has
> >a diagnosis.
> >
> >1. When lowering to the ground the jacked up right front wheel on my
> >Transmode, I heard a clunk and felt the wheel shift inwards as it
> >settled to the ground and supported the weight of the coach on that
> >side.
> >
> >2. I jacked the coach back up and with the wheel off the ground I
> >grabbed it at the 12:00 and 6:00 o'clock postions and gave it a tug. To
> >my chagrin there was about a 1/2 inch in and out movement in the wheel.
> >
> >3. Now the bearings, hub, lower ball joint and drive axle on that side
> >were all replaced last year and about 10,000 miles ago.
> >
> >4. Recalling Patrick's recent account of discovering the axle nut
> >"finger tight" on one of his wheels, I checked the nut on mine, and low
> >and behold, it too was loose. The cotter pin was in place but I
> >remember seeing the mechanic use a air wrench to torque the nut on the
> >axle last year.
> >
> >5. I retorqued the nut to about 200 ft-lbs with the wheel on the ground.
> >This took all the play out of the wheel that I had before. Thank
> >goodness.
> >
> >6. However (there's always a 'however') the "clunk" is just as bad as
> >before. It sounds like something is shifting in position relative to
> >another part when enough weight is in play as the supporting bottle jack
> >retracts.
> >
> >7. I can see or feel no movement in the ball joints (top and bottom),
> >the control arms, sway bar, or wheel.
> >
> >Is it possible for the wheel bearings to be shifting? How would I tell?
> >What would cause the axle nut to come loose?
> >
> >Ah, this GMC is a puzzle.
> >
> >Thanks,
> >Phil Stewart
> >
> >
>