GAWR - Spartan rating vs. Axle mfr rating...

[TDInewguy]

Hey gang,

I'm looking at a 2009 Newmar Dutchstar with a Spartan chassis...

It has a 20,000lb rating from Spartan, and I called to confirm that with the fine folks at Spartan... They checked the build sheet and doubly confirmed the rating.

I looked up the part number of the axle and called Meritor about it - and they rated the axle at 19,000 lbs. In fact they only make that model in a 17, 19 and 21k rating.

The axle part# is a RS19145
And the brochure from the 2009 Dutchstar 4043 clearly states it is a 20,000lb rear rating.

So what gives? How did Spartan re-class the axle to a higher weight rating?

[Blaster_Man]

Two Jayhawks wrote:
Strange. I have the opposite of that scenario my drive is 21K per the axle mfg and Newmar down rates it to 20K. Hopefully the unit you are looking at has a tag which mean you'll have more capacity than you would ever use even with the 19K drive.

Same here. I was told by the chassis manufacturer that the axle rating is the lowest rating of all the components of the axle and parts. The lowest rating of all associated parts is the rating the "axle" gets.

[eheading]

Have you asked Spartan how they got the rating up to 20,000 pounds from 19000? They are certainly a very reliable company. Seems the simplest place to start is to ask Spartan to explain this apparent discrepancy. I would be most interested to hear what their answer is.

Ed Headington

[tatest]

I can understand Newmar re-rating a 21,000 pound axle to 20,000 pounds, to stay within DOT maximum per axle ratings for the Interstate highway system. That's a licensing matter, more than physical capability.

I'm not sure how Newmar would up-rate a 19,000 axle to 20,000.

[timmac]

I don't know how Spartan rates the axle but the Ford F-53 uses one axle for the 18000 lb, 20,500 lb and 22,000 lb chassis, what is different is the thickness of the leaf springs and tire size, maybe that is what Spartan dose as well, or bigger air bags if that is what is in place of leaf springs.

Oh and the brakes might be bigger as well for the 22,000 lb chassis.

[imgoin4it]

Can understand Newmar rating it lower for some very good reason/s. Could be because of tire size or tire pressure to get a better ride are a couple, etc. But cannot imagine any case for increasing the rating.

[crasster]

That is a bit weird. Did they add any mods to the axle or put mount supports that would allow the engineers to rate it 1,000 higher?

[Two_Jayhawks]

Strange. I have the opposite of that scenario my drive is 21K per the axle mfg and Newmar down rates it to 20K. Hopefully the unit you are looking at has a tag which mean you'll have more capacity than you would ever use even with the 19K drive.

[ILVMYGT]

Since you know the manufacture of the axle I would go under the coach and get the manufacture label plate information from the axle. I found mine and the label plate had the part number and weight rating stamped on it. Review manufacture web site or call them to find the location of the label plate. The label plate may need to be cleaned with some solvent to make it readable.