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[GMCnet] Front end "Rumble" ??? [message #70258] Sat, 09 January 2010 18:40 Go to next message
Bruce is currently offline  Bruce   United States
Messages: 18
Registered: February 2004
Karma: 0
Junior Member


Been noticing a new "Rumble" in the right front of my coach the last few
times I have been out. It sounds like when you put big "Off -road" tires on
your truck. Tires are 3 yr old V-Steels and in great looking shape and
inflated properly.

It seems to start around 30 mph and gets quieter around 65. "On or Off"
the throttle has no effect nor does braking so I don't think it is the final
drive or front wheel bearings... usually braking will change the wheel
bearing noise. Bearings are less than 12,000 miles. Also does it with the
engine off and coasting down a hill ... different road surfaces don't change it
either... concrete to asphalt.

Replaced the "drive shaft extension bearing" which was shot but no change.
Could be the final drive bearing I guess.

Just lifted the front end with my forklift and ran it up to 45 with the
wheels in the air and it is quiet. So... I rotated out the front tire to the
back and we will see...

Any other ideas???

Thanks!
Bruce in Santa Barbara




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Re: [GMCnet] Front end "Rumble" ??? [message #70263 is a reply to message #70258] Sat, 09 January 2010 19:22 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Bruce,

When were the CV joints last inspected / serviced?

Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426


-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of bruceprototype@aol.com
Sent: Sunday, 10 January 2010 11:40 AM
To: gmclist@temp.gmcnet.org
Subject: [GMCnet] Front end "Rumble" ???

Been noticing a new "Rumble" in the right front of my coach the last few
times I have been out. It sounds like when you put big "Off -road" tires on
your truck. Tires are 3 yr old V-Steels and in great looking shape and
inflated properly.

It seems to start around 30 mph and gets quieter around 65. "On or Off" the
throttle has no effect nor does braking so I don't think it is the final
drive or front wheel bearings... usually braking will change the wheel
bearing noise. Bearings are less than 12,000 miles. Also does it with the
engine off and coasting down a hill different road surfaces don't change it
either... concrete to asphalt.

Replaced the "drive shaft extension bearing" which was shot but no change.
Could be the final drive bearing I guess.

Just lifted the front end with my forklift and ran it up to 45 with the
wheels in the air and it is quiet. So... I rotated out the front tire to the
back and we will see.

Any other ideas???

Thanks!
Bruce in Santa Barbara


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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Front end "Rumble" ??? [message #70276 is a reply to message #70258] Sat, 09 January 2010 20:20 Go to previous messageGo to next message
Bruce is currently offline  Bruce   United States
Messages: 18
Registered: February 2004
Karma: 0
Junior Member




CV's serviced with bearings... 12k miles or so...


In a message dated 1/9/2010 5:22:16 P.M. Pacific Standard Time,
robmueller@iinet.net.au writes:
Bruce,

When were the CV joints last inspected / serviced?

Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426


-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of
bruceprototype@aol.com
Sent: Sunday, 10 January 2010 11:40 AM
To: gmclist@temp.gmcnet.org
Subject: [GMCnet] Front end "Rumble" ???

Been noticing a new "Rumble" in the right front of my coach the last few
times I have been out. It sounds like when you put big "Off -road" tires on
your truck. Tires are 3 yr old V-Steels and in great looking shape and
inflated properly.

It seems to start around 30 mph and gets quieter around 65. "On or Off" the
throttle has no effect nor does braking so I don't think it is the final
drive or front wheel bearings... usually braking will change the wheel
bearing noise. Bearings are less than 12,000 miles. Also does it with the
engine off and coasting down a hill different road surfaces don't change it
either... concrete to asphalt.

Replaced the "drive shaft extension bearing" which was shot but no change.
Could be the final drive bearing I guess.

Just lifted the front end with my forklift and ran it up to 45 with the
wheels in the air and it is quiet. So... I rotated out the front tire to
the
back and we will see.

Any other ideas???

Thanks!
Bruce in Santa Barbara


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Re: [GMCnet] Front end "Rumble" ??? [message #70278 is a reply to message #70258] Sat, 09 January 2010 20:47 Go to previous messageGo to next message
Craig Lechowicz is currently offline  Craig Lechowicz   United States
Messages: 541
Registered: October 2006
Location: Waterford, MI
Karma: 0
Senior Member
Bruce wrote:
>Been noticing a new "Rumble" in the right front of my coach the last few
times I have been out.

Bruce, I haven't had an issue with my GMC m/h yet, but in the last few months changed a rear wheel bearing in my Fiero and a front one in my Trailblazer. Neither one changed with different throttle openings and they both started to make noise around 25 mph and were worse around 40. Then either got a little better going faster or were more drowned out by the increasing other noises at speed. If it's the right front, it should get worse when you swerve to the left, and quieter when you swerve to the right. This was very noticeable on the Trailblazer front wheel bearing. With the Fiero rear one, turning didn't make any difference at all. On both vehicles, you couldn't hear the noise with it running on jack stands (even did the screwdriver to the bearing housing thing). Summarizing there, the bearing is noisier with more weight on it which is why turning away from it makes it worse, and having it on jacks or turning the other makes it quieter. One last thing, the Fiero you could feel just the slightest "play" when wobbling the wheel and the Trailblazer you couldn't feel any at all. (these were both the sealed lube for life type hub and bearing together though, so a different construcion than the GMC). Still, that might help you diagnose it a little better. Another thing you might do is drive through a narrow bridge or building close to the road, as the echo might make it easier to hear what is going on.


Craig Lechowicz
'77 Kingsley, Waterford, MI
Re: [GMCnet] Front end "Rumble" ??? [message #70281 is a reply to message #70278] Sat, 09 January 2010 21:06 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Bruce,

I just thought of something - what brand / part number of wheel bearings do
you have in the GMC.

I have received an email from a well respected GMCer about wheel bearing
failure at 3000 miles on both wheels because the shop fitted Japanese
bearings.

He noted that the CORRECT set for a GMC's are Timken Set 23 with a spacer
that provides 0.0095 bearing clearance. The ones for a Toronado are not
correct as the bearing clearance is different.

Here's a link to a company that sells them:

http://www.jbr17llc.com/set231.html

I bought two sets from them and verified the bearing spacers are marked
0.0095 when they arrived.

Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426


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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Front end "Rumble" ??? [message #70283 is a reply to message #70278] Sat, 09 January 2010 21:18 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
Rob,
They did not have any stock last time we checked.

On Sat, Jan 9, 2010 at 6:47 PM, Craig Lechowicz
<craig.lechowicz@sbcglobal.net> wrote:
>
>
> Bruce wrote:
>>Been noticing a new "Rumble" in the right front of my coach the last few
> times I have been out.
>
> Bruce,  I haven't had an issue with my GMC m/h yet, but in the last few months changed a rear wheel bearing in my Fiero and a front one in my Trailblazer. Neither one changed with different throttle openings and they both started to make noise around 25 mph and were worse around 40.  Then either got a little better going faster or were more drowned out by the increasing other noises at speed.  If it's the right front, it should get worse when you swerve to the left, and quieter when you swerve to the right.  This was very noticeable on the Trailblazer front wheel bearing.   With the Fiero rear one, turning didn't make any difference at all.  On both vehicles, you couldn't hear the noise with it running on jack stands (even did the screwdriver to the bearing housing thing). Summarizing there, the bearing is noisier with more weight on it which is why turning away from it makes it worse, and having it on jacks or turning the other makes it quieter.  One last thing, the Fiero yo
>  u could feel just the slightest "play" when wobbling the wheel and the Trailblazer you couldn't feel any at all.  (these were both the sealed lube for life type hub and bearing together though, so a different construcion than the GMC).  Still, that might help you diagnose it a little better.  Another thing you might do is drive through a narrow bridge or building close to the road, as the echo might make it easier to hear what is going on.
> --
> Craig Lechowicz
> '77 Kingsley, Waterford, MI
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>



--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] Front end "Rumble" ??? [message #70284 is a reply to message #70258] Sat, 09 January 2010 21:23 Go to previous messageGo to next message
shawnee is currently offline  shawnee   United States
Messages: 422
Registered: February 2004
Location: NC
Karma: 0
Senior Member
Bruce wrote on Sat, 09 January 2010 19:40



Been noticing a new "Rumble" in the right front of my coach the last few
times I have been out. It sounds like when you put big "Off -road" tires on
your truck. Tires are 3 yr old V-Steels and in great looking shape and
inflated properly.

It seems to start around 30 mph and gets quieter around 65. "On or Off"
the throttle has no effect nor does braking so I don't think it is the final
drive or front wheel bearings... usually braking will change the wheel
bearing noise. Bearings are less than 12,000 miles. Also does it with the
engine off and coasting down a hill ... different road surfaces don't change it
either... concrete to asphalt.

Replaced the "drive shaft extension bearing" which was shot but no change.
Could be the final drive bearing I guess.

Just lifted the front end with my forklift and ran it up to 45 with the
wheels in the air and it is quiet. So... I rotated out the front tire to the
back and we will see...

Any other ideas???

Thanks!
Bruce in Santa Barbara




Bruce,

I had the same problem. I checked each rear wheel bearings and they were OK. The front bearings seemed to check out OK also. I started looking at the rear tires and noticed a couple flat spots on one of the rear tires. I replaced the tire and everything was OK. On the road it sounded like it was coming from the left front wheel. The tire that had flat spots was on the rear left wheel.


Gene Dotson
74 Canyonlands
www.bdub.net/Motorhome_Enhancements New Windows and Aluminum Radiators
Re: [GMCnet] Front end "Rumble" ??? [message #70287 is a reply to message #70283] Sat, 09 January 2010 21:25 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
If your not smart enough to check clearances after you press them on
the spindle, you deserve to pay the penalty.
Now if your using Dave L. Spindle, you'll not need to check as he
checks each and every one.
Does not make any difference what bearing you use, if clearance is not
checked after it is pressed, your gambling.

On Sat, Jan 9, 2010 at 7:18 PM, Jim Kanomata <jimkanomata@gmail.com> wrote:
> Rob,
> They did not have any stock last time we checked.
>
> On Sat, Jan 9, 2010 at 6:47 PM, Craig Lechowicz
> <craig.lechowicz@sbcglobal.net> wrote:
>>
>>
>> Bruce wrote:
>>>Been noticing a new "Rumble" in the right front of my coach the last few
>> times I have been out.
>>
>> Bruce,  I haven't had an issue with my GMC m/h yet, but in the last few months changed a rear wheel bearing in my Fiero and a front one in my Trailblazer. Neither one changed with different throttle openings and they both started to make noise around 25 mph and were worse around 40.  Then either got a little better going faster or were more drowned out by the increasing other noises at speed.  If it's the right front, it should get worse when you swerve to the left, and quieter when you swerve to the right.  This was very noticeable on the Trailblazer front wheel bearing.   With the Fiero rear one, turning didn't make any difference at all.  On both vehicles, you couldn't hear the noise with it running on jack stands (even did the screwdriver to the bearing housing thing). Summarizing there, the bearing is noisier with more weight on it which is why turning away from it makes it worse, and having it on jacks or turning the other makes it quieter.  One last thing, the Fiero yo
>>  u could feel just the slightest "play" when wobbling the wheel and the Trailblazer you couldn't feel any at all.  (these were both the sealed lube for life type hub and bearing together though, so a different construcion than the GMC).  Still, that might help you diagnose it a little better.  Another thing you might do is drive through a narrow bridge or building close to the road, as the echo might make it easier to hear what is going on.
>> --
>> Craig Lechowicz
>> '77 Kingsley, Waterford, MI
>> _______________________________________________
>> GMCnet mailing list
>> List Information and Subscription Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>>
>
>
>
> --
> Jim Kanomata
> Applied/GMC, Fremont,CA
> jimk@appliedairfilters.com
> http://www.appliedgmc.com
> 1-800-752-7502
>



--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] Front end "Rumble" ??? [message #70289 is a reply to message #70276] Sat, 09 January 2010 21:39 Go to previous messageGo to next message
Charles is currently offline  Charles   United States
Messages: 455
Registered: January 2004
Karma: 0
Senior Member
Bruce,
Drive the coach and have someone ride in a car and watch the wheels
and listen to the coach from the outside. They might spot the problem
or narrow down where the rumble is comming from. Wheel bearings,
tires, CV joints, Fan Cluch. Bearings on fan belt items, Loose Damper
pully and on and on and on.
Good luck.
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Charles Wersal
Duncanville, Texas
26 foot 1975 Glenbrook
Pandora's Box

Re: [GMCnet] Front end "Rumble" ??? [message #70290 is a reply to message #70258] Sat, 09 January 2010 21:43 Go to previous messageGo to next message
Bruce is currently offline  Bruce   United States
Messages: 18
Registered: February 2004
Karma: 0
Junior Member
Well... I switched the RF tire with the RH middle tire and about 80% of the
noise went away. The RF tire had 2 big weights on it and the RH middle had
only one small one. Bearings were new 12k miles ago. I had Ken Thoma
rebuild a set of knuckle/hub assemblies for me years ago as a spare set .... so
everything was set-up by him. After that I was working on my 2500HD hub
project so I didn't really think I would be using stock knuckles again but I just
ran out of time and put the Thoma knuckles on about a year and a half
ago... along with the tires.
The thing that I don't get is why I ran 12k miles with that tire up front
and didn't notice the noise and then it came on within a few thousand miles?
Tire looks fine but I guess it is going to become a spare.
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Re: [GMCnet] Front end "Rumble" ??? [message #70333 is a reply to message #70258] Sun, 10 January 2010 08:22 Go to previous messageGo to next message
Steven Ferguson is currently offline  Steven Ferguson   United States
Messages: 3447
Registered: May 2006
Karma: 0
Senior Member
Bruce,
The kind of rumble you're describing is usually associated with rear
wheel bearing distress. Ask me or Dan G. how we know this. The first
thing to find out is if it is really coming from the front or if it is
telegraphing from the rear.

On Sat, Jan 9, 2010 at 5:40 PM, <bruceprototype@aol.com> wrote:
>
>
> Been noticing a new "Rumble" in the right front of my coach the last few
> times I have been out. It sounds like when you put big "Off -road" tires on
> your  truck. Tires are 3 yr old V-Steels and in great looking shape and
> inflated  properly.


--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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Re: [GMCnet] Front end "Rumble" ??? [message #70352 is a reply to message #70258] Sun, 10 January 2010 10:15 Go to previous message
Bruce is currently offline  Bruce   United States
Messages: 18
Registered: February 2004
Karma: 0
Junior Member


I will give them a check... Thanks!



In a message dated 1/10/2010 6:22:44 A.M. Pacific Standard Time,
botiemad11@gmail.com writes:
Bruce,
The kind of rumble you're describing is usually associated with rear
wheel bearing distress. Ask me or Dan G. how we know this. The first
thing to find out is if it is really coming from the front or if it is
telegraphing from the rear.

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