Author Topic: stay or go tag axel  (Read 5062 times)

Offline Lonnie time to go

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stay or go tag axel
« on: June 06, 2008, 02:53:22 PM »
1975 4905  I will be towing a car behind when I travel.
Can i get better mpg with or without the tag.
I can put tanks where the tags are or in the other storage bays I am not worried to much about
storage.
bottom line is it better to keep it for extra braking or let it go for less weight
1976 4905

Offline JackConrad

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Re: stay or go tag axel
« Reply #1 on: June 06, 2008, 03:12:57 PM »
Don't know abouit a GM, but on the MC-7,8,9s, the tag also makes the bus handle much better. Jack
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Offline roadrunnertex

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Re: stay or go tag axel
« Reply #2 on: June 06, 2008, 03:43:26 PM »
The retractable tag axle on a GMC 4905 Buffalo was a option.
My GM 4905 did not have the retractable tag axle from the factory. ;D
You can remove the retractable tag axle assembly and use the 3rd baggage bin for you potable and waste water tanks
Also you will only have 2 axles on the GM coach not 3 like the other makes that have to pay toll charges for that extra axle.
The maintenance manual for the above GM coaches explain how to remove retractable the tag axle.
I would say that if it were me the retractable tag axle would be gone.
jlv ::)

Offline Ray D

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Re: stay or go tag axel
« Reply #3 on: June 06, 2008, 05:53:11 PM »
But darned, they look so cool...

Ray D

Offline Barn Owl

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Re: stay or go tag axel
« Reply #4 on: June 06, 2008, 10:36:30 PM »
The short answer is to remove them, as they are not needed in a conversion.
L. Christley - W3EYE Amateur Extra
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Offline Bob Gil

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Re: stay or go tag axel
« Reply #5 on: June 07, 2008, 05:59:39 AM »
Sounds like a win win deal to me. 

You lose the extra weight and lose the extra cost of maintain the axle like tires and brakes and such.
Fort Worth, Texas where GOD is so close you don't even need a phone!

1968 GM Bus of unknown model 6V53 engine (aftermarket) converted with house hold items.

Had small engine fire and had no 12 volt system at time of purchase. 
Coach is all 110 w 14KW diesel genrator

Offline rv_safetyman

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Re: stay or go tag axel
« Reply #6 on: June 07, 2008, 03:12:30 PM »
Can't speak to the GMs, but I believe that most bus conversions are very close to the GVW.  Many are over.  While we don't have the passengers, and baggage, we have some very heavy equipment (generator, fridge, lots of water/gray/black, tons of "stuff" etc.

We had a fellow in the Eagle chapter that removed the tag and found that his axle weights were quite high compared to their ratings.

If you want to remove the tag, have the bus weighed first and see where you are and how the axles are loaded.  It is a very easy to calculate how removing an axle will load the others (statically).  That is a very important consideration.  However, the dynamic loads are an even bigger consideration and almost impossible to calculate. 

Not only do you have to be concerned about the tire and axle loadings of the remaining axles, you also need to be concerned about the impact on the structure loading.

Lastly, if you would ever be involved in an accident, you could be in deep dodo.  You have removed a significant percentage of the brake capacity.

Just a few thoughts

Jim
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Offline pabusnut

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Re: stay or go tag axel
« Reply #7 on: June 07, 2008, 03:34:35 PM »
I had a tag axle in my 1973 4905 when I bought it.  After much consultation, I decided to remove it and build a bay floor back into that space.  When you look at the gvw for the bus with the axle, it supposedly added 5K to the gvw, but weighed in at over 2200 lb, so the net gain was only 2800 lbs! 

For me, it is more worthwhile to have that amount of cubic area back for my "utilities bay" than to have the extra weight capacity.  I plan to do a light conversion, so I doubt I will even get close to the gvw.

As for removing the tag axle it is not difficult, but just remember that you either need to add pieces from a scrapped bus to build a floor for original design strength, or build your own.  I built my own, and the only concern I have is that it might not "flex" as much as an original floor.

Steve Toomey

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Offline tekebird

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Re: stay or go tag axel
« Reply #8 on: June 07, 2008, 05:49:51 PM »
see I would say that most conversion are much lower than gross, except for some professinal conversion which tend to get on the heavy side.


Offline Len Silva

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Re: stay or go tag axel
« Reply #9 on: June 07, 2008, 05:55:14 PM »
I think that if you are careful with the ceramic tile and granite, you will probably be OK.  Wi8th today's concerns about fuel economy, weight control becomes more of a factor than it might have been in the past.

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Offline Barn Owl

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Re: stay or go tag axel
« Reply #10 on: June 07, 2008, 06:20:45 PM »
One thing that needs to be mentioned again is that the tag on the 4905 was an option, and they were designed from the start to work fine without them. I believe it was more of a requirement of some state laws than an engineering issue.
« Last Edit: June 07, 2008, 06:22:41 PM by Barn Owl »
L. Christley - W3EYE Amateur Extra
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Offline 4905 doc

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Re: stay or go tag axel
« Reply #11 on: June 08, 2008, 04:27:57 AM »
Pull it out. 

Offline Kwajdiver

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Re: stay or go tag axel
« Reply #12 on: June 08, 2008, 10:27:53 AM »
Hummmmm,  now you guys have me thinking,,,, ???

What is the GVW on a MCI-9 for passenger sevice?   I know, my 9 weight in as some 33,700lbs.

Bill
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Offline gus

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Re: stay or go tag axel
« Reply #13 on: June 09, 2008, 11:17:19 AM »
I did the math long ago and the conversion weight is a fraction of the original with 41 passengers, luggage and freight plus the original AC equipment.

No contest.
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Offline JackConrad

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Re: stay or go tag axel
« Reply #14 on: June 09, 2008, 02:24:07 PM »
Bill,
  The plate on our MC-8 says front axle 12,500, drive axle 22,000 and tag axle 6,000. Then list max GVW at 36,500  Jack
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