New drums to correct running gear imbalance?

[Inland RV Center, In]

Originally Posted by Lipets

I have a hard time seeing the need to balance the wheels with the drum.

I never heard of this being done on cars-trucks.

It has been working on millions of cars for years without doing this.

Anybody backup this procedure with doc's from the manufacturer

This subject was tossed around on this site a long time ago.

All automobile and light truck hub and drums are balanced when manufactured.

That "is not" the case with "any" travel trailer hub and drum, be it an assembly or unicast, ever made as of today.

Part of the theory seems to be that since you don't ride in the trailer, then "who cares" if it shakes. Also, there is a cost to balance them, it seems to most manufacurers, to be high enough to price themselves out of market.

Accordingly, you "must" balance the tire and wheel "and" the hub and drum, as an assembly.

It's your investment, therefore your choice. The vast majority of Airstream owners, chose to abide by the proper "PM" principles. Some of them, unfortunately, learned that lesson, the hard way.

From 1973 and back, the primary cause of rear end separation, as well as many other problems, was "lack" of proper running gear balance. From 1973 up to and including today, lack of proper running gear balance is an absolute guarantee of crazy and usually expensive repairs, that could have, so very easily, been avoided.

Therefore, in time, the message became loud and clear. Balance the running gear, or else.

Andy

[TomW]

Originally Posted by Inland Andy

...All automobile and light truck hub and drums are balanced when manufactured.

That "is not" the case with "any" travel trailer hub and drum, be it an assembly or unicast, ever made as of today....Accordingly, you "must" balance the tire and wheel "and" the hub and drum, as an assembly.

It's your investment, therefore your choice. The vast majority of Airstream owners...

Andy,

Since balancing drums is apparently commonplace, why does Airstream Inc. choose not to have their axle vendor do it on new assemblies? Obviously it will add dollars to the purchase price, but what new purchaser would notice? It appears to me to be a good selling point.

Tom

[Inland RV Center, In]

Originally Posted by TomW

Andy,

Since balancing drums is apparently commonplace, why does Airstream Inc. choose not to have their axle vendor do it on new assemblies? Obviously it will add dollars to the purchase price, but what new purchaser would notice? It appears to me to be a good selling point.

Tom

Henschen and Dexter do not balance drums.



Andy

[TomW]

Originally Posted by Inland RV Center, In

Henschen and Dexter do not balance drums.

I would not know.

But if they do not, other companies do. Whoever makes the drums for the two companies could ship the drums to another party for balancing.

So [a modifcation on the question] still remains - Why does Airstream Inc. choose not to have their axle assemblies balanced before incorporation into a new Airstream?

Tom

[Action]

Originally Posted by TomW

But if they do not, other companies do. Whoever makes the drums for the two companies could ship the drums to another party for balancing.
Tom

I do not know for sure, and I would guess that the axle manufactures make ther own drums. And I would also guess that no trailer axle company balances their braking assemblies. For if you look at the end user, utillity trailers, HD equipment used at slower speeds, then it might be assumed the market dictates that there isn't much need for balanced braking assemblies. Just a guess on my part.

In the automotive arena, most automanufactures make there own running gear or contract out for it in a balanced condition. And most automotive applications use disc braking or smaller drums in the rear. The smaller the drum the less concern for rotating mass. And rotors are far easier to keep balanced.

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[markdoane]

I'm sure with all the Millions of dollars that Airstream has spent on product design and engineering, they have decided that it is not necessary to balance the drums.

That's my opinion and I'm sticking with it.

[Jim & Susan]

Andy, I'm missing something here. What happened in 1973 that changed things? I have a 1973 so I'm curious. Are you saying that all trailers built after 1973 need to have the drum assembly balanced with the wheels/tires? Help a rookie axle guy out here, how is that done? I rememeber the "old days" when tires/wheels/etc could all be spin balanced while mounted on the car/truck. This can only be done by a few shops these days?

Jim

[axleman]

Originally Posted by markdoane

I'm sure with all the Millions of dollars that Airstream has spent on product design and engineering, they have decided that it is not necessary to balance the drums.

That's my opinion and I'm sticking with it.

Don,

I would be curious of the cost to do the balance job vs. the necessity. In other words you may be right - it's not worth the cost. Uwe has tried it both ways and didn't seem to notice a difference.

Regards,
Henry

[Pahaska]

I have had Centramatics on my last 2 Airstreams and, based on things staying nicely in place while underway, I am convinced that they do a good job of balancing the running gear.

Cost is about $200 for a set of 4 and installation is a snap. Just remove the wheel, slip the balancer on the studs, and reinstall the wheel. They look nice, as well.

[markdoane]

Originally Posted by axleman

Don,

I would be curious of the cost to do the balance job vs. the necessity. . .
Regards,
Henry

Henry,

I think the cost would be under $10/wheel if done by the manufacturer, using an automated horizontal balancing machine like this: http://www.schenck-usa.com/prod_hori...mach_auto.html

The bigger issue is how do you market the idea. As the manufacturer, do you want to tell the whole world that what you've been making and selling unbalanced hubs and drums for the last 75 years? Do you change over your whole product line, or do you sell two product lines, balanced and unbalanced? Does that give rise to some product liability issues if an unbalanced hub causes an accident? How will the competition respond? What if everyone starts buying disc brakes and your new balancing machine sits idle most of the time? What if the Chinese start making drums that are better and are cheaper?

I'm afraid the trailer wheel and axle business is going to disappear in the US if no one is willing to invest in new technology.

[axleman]

Originally Posted by markdoane

Henry,

I think the cost would be under $10/wheel if done by the manufacturer, using an automated horizontal balancing machine like this: http://www.schenck-usa.com/prod_hori...mach_auto.html

The bigger issue is how do you market the idea. As the manufacturer, do you want to tell the whole world that what you've been making and selling unbalanced hubs and drums for the last 75 years? Do you change over your whole product line, or do you sell two product lines, balanced and unbalanced? Does that give rise to some product liability issues if an unbalanced hub causes an accident? How will the competition respond? What if everyone starts buying disc brakes and your new balancing machine sits idle most of the time? What if the Chinese start making drums that are better and are cheaper?

I'm afraid the trailer wheel and axle business is going to disappear in the US if no one is willing to invest in new technology.

Don,

Wow.

Well let's see -
First - you market it to Airstream. If Airstream demanded it and would pay - an axle manufacturer would do it. Like you said previously, if it were a requirement - they would demand it.

Second - You offer it as an upgrade. Axles are a nickel and dime business - most axle manufacturers fight for small amounts of money. Most customers, that buy axles, buy on price first.

Third - the Chineese do make about 50% of trailer drums sold in the USA - maybe more.

Forth - some axle companies do invest in technology. However the technology has to benefit the masses - I think (like shocks on a torsion axle) Airstream would be the only company that may (heavy on the may) buy a balanced drum.

It is of my opinion (based on years in the axle business) that 99% of folks would not spend $20.00 per axle to solve a problem they don't really have.

Just two cents from a retired axle dude,
Henry

[Action]

From the manufacturing end, $40 would be a big number for 4 wheeels. I don't know how many Airstream trailers with drum brakes are made each year. If it were 7000 and most had 4 drums, that is a million dollars in 4 years. This would drive up the MSRP if that were the case. And those trailers are expensive enough.

When I worked at Ford a $1.00 item was a big deal. And that was spread over many thousands or sometimes millions of units in a year. Airstream doesn't have the competition that an auto manufacturer has, and it still has to play in the market place with the white boxes.

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