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07-07-2009, 12:52 PM
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#1
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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How did this happen, OEM axles under-rated
While checking thru the owners manual today I came across something that concerns me a LOT. Our 03 25' Classic was delivered with a pair of 3500lb Hencshen's on a GVWR of 7300lbs.
I've scaled out at 7580lbs loaded for camping, knowing I was 280lbs over, not 580... BTW Just weighed the tongue today with the new Sherline scale..960lbs w/Hensley. 1540lbs.
Now what?...'yeah I know new axles, but this is something that just shouldn't happen. Anyone else found the same problem? Or is there something I'm missing?
Be careful everyone, don't assume, check your specs.
Bob
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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07-07-2009, 01:41 PM
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#2
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Rivet Master
Airstream Dealer
Corona
, California
Join Date: Feb 2002
Posts: 16,497
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Quote:
Originally Posted by ROBERT CROSS
While checking thru the owners manual today I came across something that concerns me a LOT. Our 03 25' Classic was delivered with a pair of 3500lb Hencshen's on a GVWR of 7300lbs.
I've scaled out at 7580lbs loaded for camping, knowing I was 280lbs over, not 580... BTW Just weighed the tongue today with the new Sherline scale..960lbs w/Hensley. 1540lbs.
Now what?...'yeah I know new axles, but this is something that just shouldn't happen. Anyone else found the same problem? Or is there something I'm missing?
Be careful everyone, don't assume, check your specs.
Bob
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Bob,
Henschen many years ago, built the chassis for Airstream.
When they built the chassis, they also installed the axles, and therefore had the axle rating for each individual length trailer.
Sometime prior to 1996, Henschen no longer built the chassis.
Ever since that time, Airstream ordered a variety of axle ratings, without ever telling Henschen what size trailers they were going to be installed on.
Accordingly, the axle ratings that were installed by Airstream, was of their sole choosing. Henschen had nothing to do with it, and therefore has no records of what was used, on what.
I would agree that in your case, the rating should have been a little higher.
Andy
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07-07-2009, 03:11 PM
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#3
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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Thank's Andy..
I sure would feel more comfortable with 4000# axles.
I'm a bit "old school" and have always added the tongue weight to the GVWR,
I'll try and deal with the 580 lbs over and forget the 1540 number.
It was brought to my attention that the factory doesn't take into consideration the the weight of the axles, tires, brakes etc. in their GVWR figures, so there's the un-sprung weight factor also...sorry just trying to rationalize here.
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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07-07-2009, 04:44 PM
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#4
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Rivet Master
2004 25' Classic
Prescott
, Arizona
Join Date: Jul 2008
Posts: 623
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I sure am glad someone else is questioning that, The 2004 Classic has the same 3500lbs axles. How are they allowed to rate it higher than what the axles will hold? Is it even legal to have it this way?
Bob
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07-07-2009, 05:37 PM
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#5
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Rivet Master
Join Date: Nov 2008
Posts: 1,177
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Perhaps they are using the unsprung weight and not allowing for the additional weight due to the tongue and weight transfered due to the hitching?
Try weighing your trailer without the axles, wheels, brakes, tires and tow vehicle transfers, and let us know how that goes
I'll bet it's road-ready, without all that silly stuff attached to it.
Good luck,
Rich
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07-07-2009, 05:41 PM
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#6
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Rivet Master
1965 17' Caravel
1983 27' Excella
Walnut Grove/Laguna Woods
, California
Join Date: Jun 2004
Posts: 1,635
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I just put a pair of #3,500 axles on our '83 27' Excella. The book shows the trailer to weigh about 5,600 lbs. No water, no stuff inside, no nothing. The old axles were a pair of #2,800 installed new. No wonder they were worn out and the trailer was a "low rider".
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07-07-2009, 05:45 PM
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#7
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Rivet Monster
1975 31' Sovereign
1980 31' Excella II
Sprung Leak
, North Carolina
Join Date: Jun 2003
Posts: 7,172
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Quote:
Originally Posted by ROBERT CROSS
While checking thru the owners manual today I came across something that concerns me a LOT. Our 03 25' Classic was delivered with a pair of 3500lb Hencshen's on a GVWR of 7300lbs.
I've scaled out at 7580lbs loaded for camping, knowing I was 280lbs over, not 580... BTW Just weighed the tongue today with the new Sherline scale..960lbs w/Hensley. 1540lbs.
Now what?...'yeah I know new axles, but this is something that just shouldn't happen. Anyone else found the same problem? Or is there something I'm missing?
Be careful everyone, don't assume, check your specs.
Bob
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Actually you aren't as far over as you think you are. The weight of the wheels, brakes and what ever is on the tongue needs to be subtracted from the total weight to get the what is actually carried by the axles.
Aaron
__________________
....so many Airstreams....so little time...
WBCCI #XXXX AIR #2495
Why are we in this basket...and where are we going
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07-07-2009, 05:50 PM
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#8
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Aluminut
2004 25' Safari
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, Illinois
Join Date: Feb 2003
Posts: 10,477
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During the mid 2005 model year, Airstream started to realized this was an issue and increased the GVWR. I assume that they upgraded the axles to the next level up to achieve this increase in NCC and GVWR. This happened on all trailers from 25' up through the 34 footers. Anything south of 25 though it was my understanding that those GVWRs remained the same.
I know that the NCC is rated on a sticker on each Airstream...my 03 had this as does my 04. My NCC is about 900lbs....pretty easy target to hit when a case of be...I mean soda can weigh about 19lbs and we all only take one case of ....soda, right?
When it's time to replace my axles, I will be getting the 3500lb unit since mine is not a classic and does not have the heavier wood and I have no plans to upgrade my interior, but can easily add more than 900lbs of NCC.
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07-07-2009, 06:01 PM
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#9
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Just an old timer...
2004 22' Interstate
Tipton
, Iowa
Join Date: Mar 2003
Posts: 4,760
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I was going to say pretty much what Aaron did... you have the ability to carry 7,000 on the axles. That doesn't count the 650 or so pounds on the tongue or the weight of the running gear itself, another 600 or so pounds. The GVWR includes all that, so the actual weight of the trailer is significantly below the 7,300 lbs... by probably 1,200 lbs or so... which is about right.
Roger
__________________
havin' to fix my broken Airstreams since 1987...
AIR 2053 Current: 2004 Airstream Interstate "B-Van" T1N DODGE Sprinter
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"
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07-07-2009, 06:10 PM
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#10
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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Thanks gang I'm feel'n a little better.
Would really like to know what the actual un-sprung weight is, and what axles are now used on the 25 Classic.
At least 4k I hope. Someone ck the build sheet please.
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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07-07-2009, 07:48 PM
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#11
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Retired.
Currently Looking...
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, At Large
Join Date: Jun 2003
Posts: 21,276
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Quote:
Originally Posted by ROBERT CROSS
Thanks gang I'm feel'n a little better.
Would really like to know what the actual un-sprung weight is, and what axles are now used on the 25 Classic.
At least 4k I hope. Someone ck the build sheet please.
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Each tire/wheel weighs around 60 pounds, each brake drum is another 20 pounds, each backing plate is 10 pounds. So, figure removing almost 400 pounds from the scale weight.
__________________
Meddle not in the affairs of dragons, for you are crunchy, and taste good with ketchup.
Terry
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07-07-2009, 09:38 PM
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#12
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moderator
Commercial Member
2016 27' International
Currently Looking...
Wilton
, California
Join Date: Aug 2008
Posts: 1,711
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I just looked at mine and they are 4500# each and the GVWR is 9300#'s
Your 400#'s makes sense in wheels and axles.
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07-08-2009, 12:45 AM
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#13
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Rivet Master
2005 25' Safari
Salem
, Oregon
Join Date: Mar 2006
Posts: 8,369
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Normal.
Hi, it seems that for whatever reason Airstream has listed axle ratings at 200 to 300 lbs under the trailer's GVWR. My Safari is rated at 6,300 lbs GVWR and my axles are 3,000 lbs each. I have an Airstream sales book and all of the trailers are listed this way. I guess the unsprung weight and tongue weight allows this to work properly.
__________________
Bob 2005 Safari 25-B
"Le Petit Chateau Argent" Small Silver Castle
2000 Navigator / 2014 F-150 Eco-Boost / Equal-i-zer / P-3
YAMAHA 2400 / AIR #12144
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07-08-2009, 05:35 AM
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#14
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Restorations done right
Commercial Member
1962 26' Overlander
1961 26' Overlander
Vintage Kin Owner
Currently Looking...
Baltimore
, Maryland
Join Date: Aug 2007
Posts: 5,545
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We just took the factory tour two weeks ago. Turns out Airstream no longer uses Henchen axles. They now use Dexter.
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07-08-2009, 06:20 AM
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#15
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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Again, thanks to all.
I can accept the rational concerning the un-sprung weight issue, but there is still the concern of what the bearing assemblies and brakes are dealing with. On average the weight bars have been transferring between 175 & 210lbs back to the trailer axles. Seems to me no matter how I crunch the numbers those axles are marginal at best.
I think the 15% rule should apply here also, I would be much more comfortable knowing I had an adequate safety margin.
Has AS built in that safety margin with the new Dexter axles? Are there weight rating's the same?
Has the the GVWR's gone up on the new coach's?
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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07-08-2009, 06:29 AM
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#16
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Just an old timer...
2004 22' Interstate
Tipton
, Iowa
Join Date: Mar 2003
Posts: 4,760
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Bob, you have to remember that the GVWR, axle ratings, and maximum tongue weights are all guidelines. The maximum recommended weights are not a failure threshold. They're some engineer's idea of what you can safely carry for the life of the coach or vehicle. If your axles are rated for 7,000 lbs max and you put 7001 lbs on them, they're not going to fail. At least not immediately. You'll have a condition perhaps of premature wear... but they won't fail. Same with a hitch receiver. Eventually, if you overload it there may be a failure, but it won't be with a slight overload condition.
In other words, the components may wear more quickly overloaded and because of that should be inspected regularly (actually you should inspect this stuff regularly anyway...) but this shouldn't be anything to lose sleep over. You're just not stressing anything too much here.
Roger
__________________
havin' to fix my broken Airstreams since 1987...
AIR 2053 Current: 2004 Airstream Interstate "B-Van" T1N DODGE Sprinter
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"
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07-08-2009, 07:31 AM
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#17
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Rivet Master
Airstream Dealer
Corona
, California
Join Date: Feb 2002
Posts: 16,497
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axle ratings
Regardless of the axle manufacturer, Airstream, all by itself, selects the axle rating that will be installed on each model trailer.
That has been the case for over a decade, and then some.
Rubber must be exercised, to stay "alive".
Lack of frequent use, is the primary cause of the rubber rod failures, for the past 35 years.
Failures due to reasonable overloading, are a distant second.
Failures due to extreme permanent overloading, push for first place.
Extreme overloading would be 15 to 20 percent or more of the axle ratings, on a permanent basis, not just a single trip here and there.
Andy
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07-08-2009, 07:41 AM
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#18
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Aluminut
2004 25' Safari
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, Illinois
Join Date: Feb 2003
Posts: 10,477
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Interesting that Dexter is the new axle supplier to Airstream......
Bob, I can tell you that your model year and many around that time up until mid 2005 had grossly under rated axles. This is not only my opinion, Airstream made a major change in mid 2005 model year (many model years too late IMHO).
Your hunch is 100% correct. Roger is also correct when you slighty go past the max, it typically won't fail immediately. My take is that with late model trailers like ours made prior to the Airstream increase (mid 2005), it is beyond entirely possible to overload the axles. I believe this is why Airstream finally woke up and made the change mid 2005 model year. The slide outs IIRC were the worst, but all of them-- 25ers north to 34 footer pre mid 2005 were ridiculously low in total NCC, which in turn made it very easy to exceed the "guideline" mentioned. When I ordered my 25er, they had the options and the additional weights listed. Though my trailer had a 900lb NCC before I hit the max suggested weight, the ultraleather sofa added like 30 tp 40lbs, fantastic vent options, spice trader larger AC also took my NCC down. I believe that after all was said and done I had an NCC of about 675lbs. If one case of pop weighs 19lbs, you can see that after food, clothes, and all the other goodes we bring for us and for the trip, it's easy to hit max on late model units built prior to mid 2005 model year.
It is after mid-2005 where I would agree, that the 7000lb GVWR on my model (up from 6300) provided a greater margin of saftey and a more realisitic NCC (1600 lbs total up from 900). I was also looking at a 31' dinette at one point. I seem to recall that after the axle upgrades, the GVWR went up to 10k from about 8900lbs.
Of course now my unit and the 31' dinette are discontinued, but the upgraded axles remain on all units at 25' and above from what I can tell.
My suggestion would be when the next axle change that is needed, to go to the very next size up...in my case it would be 3500lb axles from the 3000s I have now. But as Roger said, you will most likely not have a failure if you are slightly over....300? 500? Who knows where the breaking point will be, but I would try to keep her as close as possible without going over much in the meantime.
Not that this is a complaint, but it's funny, the carrying capacity of the tires put on my unit are rated to carry a bit over 10k combined. The axles on my model are barely enough to realistically carry a reasonable 7000lbs. Glad they corrected it, though a bit late for me and you my friend.
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07-08-2009, 08:47 AM
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#19
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Restorations done right
Commercial Member
1962 26' Overlander
1961 26' Overlander
Vintage Kin Owner
Currently Looking...
Baltimore
, Maryland
Join Date: Aug 2007
Posts: 5,545
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Quote:
Originally Posted by Silvertwinkie
Interesting that Dexter is the new axle supplier to Airstream......
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I made Don repeat the statement over because I did not believe my ears. I was of the impression that Henchen were the only possible axle to be used that would not fall apart and kill an entire family. Just paraphrasing what some axle salesmen state.
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07-08-2009, 11:20 AM
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#20
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Rivet Master
Airstream Dealer
Corona
, California
Join Date: Feb 2002
Posts: 16,497
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weights
Generally speaking, 186 pounds per axle can be deducted, from the total weight.
The next weight that can be deducted, is the huge variable.
When a "proper rated hitch" is "properly installed" and "properly adjusted," then two thirds of the tongue weight can also be deducted since it's transfered to the tow vehicle.
If the tow vehicle is a car or a light truck, then two thirds of the tongue weight can also be deducted, from the total weight.
This is not applicable to every rig or situation, but it's an effort to perhaps simplify the understanding or definition of the "real weight" question.
Andy
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