Reply
 
Thread Tools Search this Thread Display Modes
 
Old 09-19-2005, 09:18 AM   #1
Rivet Master
 
Chaplain Kent's Avatar
 
1994 30' Excella
Currently Looking...
Milwaukee , Wisconsin
Join Date: May 2004
Posts: 1,934
Intermittent Chassis Vibration

On my last two trips there has been periods of chassis vibtation. First time I thought it was a flat tire, though all tires were fine. I later checked air pressure and all were good. The next time it happened I stopped again checked all around found nothing out of place and continued on. The vibration continues for about 4 to 5 minutes then stops. There are no indications of engine changes, gauges all read same and the engine sounds fine. Speed makes no difference, though I can feel the vibration in the brake pedal when slowing.
I hate to bring an intermittent problem into a mechanic without some idea as to what it may be. I also am concerned to continue driving if there is a serious problem which needs addressing.
Thanks for the ideas.
__________________

__________________
Chaplain Kent
2015 Coachman Freedom Express 19RBS, Chummy IV- Ford Excursion- 7.3 Turbo-diesel
Chaplain Kent is offline   Reply With Quote
Old 09-19-2005, 09:26 AM   #2
Just an old timer...
 
85MH325's Avatar

 
Tipton , Iowa
Join Date: Mar 2003
Posts: 4,031
Images: 37
If you can feel a vibration in your brakes, you may have warped front rotors. I ended up having to replace the brakelines, rotors, AND calipers on my '85. If you have a front caliper(s) that is sticking for whatever reason, it will overheat the rotors and cause them to shake the coach even when your foot is off the brake. Having a caliper (or calipers) or a master cylinder that is sticking is a serious problem. Eventually, it will lead to total brake failure. What actually happened on mine was that the brake lines had so deteriorated that they acted as a one-way valve, not allowing the brake fluid to return to the master cylinder reservoir after they were pressurized for a stop. That ultimately caused the calipers to fail and warped the rotors.

A tell-tale sign of caliper sticking is hot wheels... they can get VERY hot...

Roger
__________________

__________________
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"
85MH325 is offline   Reply With Quote
Old 09-19-2005, 10:43 AM   #3
Rivet Master
 
LOST , Hawaii
Join Date: Jun 2002
Posts: 2,193
Strange. If you feel it in the brake pedal logical thought would be a rotor or drum warped. But usually these don't have any feel other than in the pedal. Do you feel pulsations in the brake pedal every time when braking?

Other possible sources are tire/wheel balance and driveshaft balance (u joints and carrier bearing wear also).

John
__________________
74Argosy24MH is offline   Reply With Quote
Old 09-19-2005, 11:01 AM   #4
Rivet Master
 
ALANSD's Avatar

 
1966 26' Overlander
Woodstock , Georgia
Join Date: Feb 2002
Posts: 8,462
I would think to check the driveshaft also. Has the shaft been lubed? There are fittings on it that many people miss greasing.
__________________
1966 Overlander
AIR #005
Please visit our blogs and web pages:
OUR AIRSTREAM PASSION! BLOG
RESTORING AN AIRSTREAM
Our AIRSTREAM and TIN CAN TOURIST Rallys
ALANSD is offline   Reply With Quote
Old 09-19-2005, 01:15 PM   #5
Just an old timer...
 
85MH325's Avatar

 
Tipton , Iowa
Join Date: Mar 2003
Posts: 4,031
Images: 37
Quote:
Originally Posted by 74Argosy24MH
Strange. If you feel it in the brake pedal logical thought would be a rotor or drum warped. But usually these don't have any feel other than in the pedal. Do you feel pulsations in the brake pedal every time when braking?

Other possible sources are tire/wheel balance and driveshaft balance (u joints and carrier bearing wear also).

John
What was interesting about the brake line problem was that it also was intermittent... until finally a caliper overheated and seized. It would intermittently vibrate the motorhome like crazy though prior to seizing. Drove me nuts. Then, we still didn't catch that it was the brake lines until I ruined a SECOND caliper! The brake lines were ballooning out from being soft, and then the lining had peeled back inside acting as a one-way valve. Eventually they'd bleed back down. It was really frustrating until I found a guy who regularly worked on Chevy heavy truck chassis... he knew exactly what to look at. Apparently mine must not have been an isolated case.

Of course as John and Alan suggested, it could be U-Joints or the driveshaft as well. Or a tire balance problem, although tires will normally be repeatable at a specific speed...

Roger
__________________
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"
85MH325 is offline   Reply With Quote
Old 09-19-2005, 02:54 PM   #6
RivetAddict
 
swebster's Avatar
 
1986 34.5' Airstream 345
Louisville , Kentucky
Join Date: Feb 2003
Posts: 1,861
Images: 4
Any other clues? Does it happen at under engine acceleration or deceleration? Vibrations in the steering wheel? High pitched, low pitched? Does it "feel" like it's coming from a specific side of the coach or the front or back?

I replaced all of the UJoints, carrier bearings, front wheel bearing, front calipers, hoses, roters and pads, etc and have only now removed the last of my annoying chassis vibrations and feel like the braking system is working correctly.

I'm thinking rotors or loose wheel bearing. Maybe you could jack it up and spin each wheel by hand, look for end play in the dub, etc. Then pull the wheels and look at the brake components for out of round or true.
Had a strange vibration in my driveshaft mounted parking break that took forever to find and eliminate. It was driving me insane...whiiiiir, whiiiir, whiiiiir, I can still hear it in my sleep sometimes

Roger - very interesting information about your brakes. I personally work hard to get over spending money on the stuff that's "under the water line" but know it's the key to a safe and happy Airstream. Your story makes me glad I replaced everything.
__________________
Steven Webster
1986 Airstream 345 Classic Motorhome
AIR 1760
swebster is offline   Reply With Quote
Old 09-19-2005, 04:44 PM   #7
Rivet Master
 
Chaplain Kent's Avatar
 
1994 30' Excella
Currently Looking...
Milwaukee , Wisconsin
Join Date: May 2004
Posts: 1,934
Thanks guys for the ideas. The brakes were completly
replaced about 10,000 miles ago, including rotors, MC and lines. The drive shaft was aligned/ balanced by the PO just before we took delivery but we do have our new engine. Could this have thrown it off needing to be done again?
Speed does not affect the shaking, nor does it make a difference whether I am accerlerating or slowing down. There appears to be no pattern as to when and how long it happens and continues. It feels like it is comming from the front and evenly on both sides.
__________________
Chaplain Kent
2015 Coachman Freedom Express 19RBS, Chummy IV- Ford Excursion- 7.3 Turbo-diesel
Chaplain Kent is offline   Reply With Quote
Old 09-19-2005, 05:09 PM   #8
RivetAddict
 
swebster's Avatar
 
1986 34.5' Airstream 345
Louisville , Kentucky
Join Date: Feb 2003
Posts: 1,861
Images: 4
I'll bet there is a GMC truck shop in your area that works on Medium Duty and Heady Duty trucks. When I was chasing vibrations I talked with the service manager at our local repair facility. He said they have a lift which allows them to run the chassis up to speed and using sensor pinpoint the source of chassis vibrations. I don't remember the cost but it was not super expensive.

Might be a good way to find the source.

I have to wonder...anything about the new engine/tranny feel funny? Flywheel, trans yoke? IT's soooo hard to find these things when they are not obvious.
__________________
Steven Webster
1986 Airstream 345 Classic Motorhome
AIR 1760
swebster is offline   Reply With Quote
Old 09-19-2005, 05:34 PM   #9
Just an old timer...
 
85MH325's Avatar

 
Tipton , Iowa
Join Date: Mar 2003
Posts: 4,031
Images: 37
Hmmm... do these things have ball joints? Hmmm...

Roger
__________________
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"
85MH325 is offline   Reply With Quote
Old 09-19-2005, 05:37 PM   #10
2 Rivet Member
 
Orland Dewey's Avatar
 
Join Date: Mar 2003
Posts: 79
Re: vibration

Hello,

O Dewey here, Last February while heading to Florida with my 1985
325 MH I had a very serious vibration sometimes and sometimes not.
After arriving at our campgound I jacked up the front end and took both
tires off and loaded them into the van we pulled and went to a gmc and
a/s dealer in Brooksville,Fl.

The problem was the internal sending unit that tells me if I have a flat tire
had busted loose from the rim inside of the tire. This is a pretty good size
pc of material so if you have this system on your MH check it out.

Hope this is of help!

ODD (Mixednuts)
__________________
ODD
Orland Dewey is offline   Reply With Quote
Old 09-19-2005, 07:21 PM   #11
Well Preserved

 
1993 21' Sovereign
Colfax , North Carolina
Join Date: Jun 2003
Posts: 20,190
Quote:
Originally Posted by 85MH325
Hmmm... do these things have ball joints? Hmmm...

Roger
Roger, I THINK they have kingpins. This would cause intermittent vibration, but you should feel it in the steering wheel. Something it may be, is an inner wheel bearing staring to go bad. Put the front wheels up in the air, and try to wiggle the wheel around. If it moves more than about a 32nd of an inch, you have either bad bearings, bad races, both, or maybe just need to have the bearings adjusted. If the bearing was bad, it would be able to be felt in the brake pedal when braking, you may also notice the coach tending to wander off one side of the road, also known as "pulling".
It's too bad Kent is so far away, I could take a look at it this weekend at the Forum rally (shameless plug).
__________________
Meddle not in the affairs of dragons, for you are crunchy, and taste good with ketchup.
Terry
overlander63 is offline   Reply With Quote
Old 09-19-2005, 08:27 PM   #12
Rivet Master
 
LOST , Hawaii
Join Date: Jun 2002
Posts: 2,193
If you have leaf springs you have king pins, coil springs and you have ball joints. Check your tires also for tread separation.
__________________
74Argosy24MH is offline   Reply With Quote
Old 09-20-2005, 02:23 PM   #13
2 Rivet Member
 
Join Date: Jun 2002
Posts: 84
Jack up the front end - got levelers? - and shake the tires in and out top to bottom HARD and try to find something loose. Easiest find would be a loose wheel bearing - you'll get that right away and that will give your symptoms - but the ball joints are a tougher find. Unless I am mistaken, the MOOG joints are a ball captured in a metal cup with a small very tough spring on top so the joint doesn't flutter when unweighted. This makes a bad ball joint feel like a good one because it forces the ball down into the good lower cup - where it doesn't ride and where there's no wear - when you unweight the vehicle to inspect it. Maybe you even use a long 2X4 or a pipe to try and find play like they do at circle track tech. One guy levers and the other guy puts his fingers on the joint to check for play. Balljoints can make you crazy. I bet on bearings though. I think you'd get more in the brakes with the bearings and more in the steering with the joints.

If your coach porpoises a lot, you could be cupping the tires and boogering up the wheel balance too. Run your hand over the tires and see if they're smooth.

Good luck.
__________________
fangthorpe is offline   Reply With Quote
Old 09-22-2005, 07:04 AM   #14
Rivet Master
 
Chaplain Kent's Avatar
 
1994 30' Excella
Currently Looking...
Milwaukee , Wisconsin
Join Date: May 2004
Posts: 1,934
I jacked up the front and found no play in the front wheels. The tires are fairly new and have no evidence of separation or wear. My bet is the driveshaft alignment. It goes into the shop today and at least I have something to tell them. I hate it when I need to leave a vehicle and act like I know nothing. Thanks again and stay tuned for the verdict.
__________________

__________________
Chaplain Kent
2015 Coachman Freedom Express 19RBS, Chummy IV- Ford Excursion- 7.3 Turbo-diesel
Chaplain Kent is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
MH on a Toyota chassis? ViewRVs Airstream Motorhome Forums 11 07-13-2003 02:03 PM
New P-3X series Workhorse Chassis evan Airstream Motorhome Forums 6 04-19-2003 09:00 PM
Argosy 20ft MH Chassis / frame JerryT94 General Motorhome Topics 5 04-14-2003 11:33 AM
chassis paint john hd Off Topic Forum 2 10-30-2002 04:36 PM
Re-attaching cabinets to the interior skin. Andy R Cabinets, Counter Tops & Furnishings 5 04-07-2002 03:54 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 11:38 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.