Level With Me

[JRTJH]

Originally Posted by Canonman

Thanks John,
Exactly what I thought too. I'm just to simple minded to put it into words. Basically, the equalizer puts the pivot point between the two axels?

Yeap, and to go "a tad bit further", it also compensates (equalizes) the positional (height) difference between the axle C/L, the angular difference in "spring perch position" and therefore, helps to "equalize" the weight shift differences" created by those "positional changes".....

In other words, the "equalizers" do just that: "Equalize the axles"....

That said, they are not 100% effective (few things are) but they do an admirable job of keeping the "mechanical stresses within acceptable tolerance" for most applications.... In other words, "an inch of height at the pin box isn't going to mean the difference in whether you wear out your rear axle tires or break the bearings/races by overloading them.....

[dutchmensport]

The equalizer function makes good sense. It would perform differently then say, if both axles were fixed. This makes perfect sense. Thanks.

[Benbill]

Thank you for the great discussion. I am learning more everyday about my 5er, trying to be safe and smart out there on the road and camping.

[ADQ K9]

Here is a another question to throw in for tandem/ tripple axles
What about independent suspension? I don't think the axles are linked together and this is coming out as an option on some trailers now. To me it seems like it would be really critical to be level with independent supension.
Also if brakes were adjusted equally and the weight is rear biased the front axle of the trailer would lock up before the rear. The opposite would happen if the weight was front biased

[JRTJH]

Originally Posted by ADQ K9

Here is a another question to throw in for tandem/ tripple axles
What about independent suspension? I don't think the axles are linked together and this is coming out as an option on some trailers now. To me it seems like it would be really critical to be level with independent supension.
Also if brakes were adjusted equally and the weight is rear biased the front axle of the trailer would lock up before the rear. The opposite would happen if the weight was front biased

I think you're trying to put too may "similar because they look the same" concepts into one "generalized bucket"....

It's like comparing diesel engines to electric cars. Both have brakes, but the braking action/mechanisms are entirely different. You can't say, "because they both make the vehicle stop, they work the same".... Neither can you "generalize independent suspension systems have 4 or 6 wheels, therefore the weight characteristics must be similar and since that's similar, then the braking action must be the same, and since the independent torsion bar suspension doesn't use an equalizer, therefore equalizers are no longer needed in trailer applications......

It's sort of like saying that since jet aircraft don't have propellers, they can't provide forward movement, so jets can't fly. What "is true about one concept" doesn't mean it also must be true about all concepts"....

[ADQ K9]

John,
Thanks, just trying to wrap my head around the whole balance picture for a 5th wheel

[HD0707]

Another consideration is the height of a nose high 5er. Mine runs 13' 5-1/2" when level. 13'6" is legal height for most states to clear bridges. some states are 14'.

[Pmedic4]

Overall, it would seem the best answer to this is for someone to actually weigh the front and rear axles independently, raise the front of the fifthwheel 1", then 2" just to provide the corresponding information. Yes, it would be a great deal of work.

Honestly, I would be willing to bet 1" doesn't make a difference of more than 50-100 pounds, primarily based on the 'equalizer' of the axle mounting. Where it would probably show a difference is where you get 3" or more, which is beyond the range of the equalizer. Considering a 12,000 pound trailer, with 2,500 pounds on the hitch, the axles are still carrying 4,750 pounds each axle. I have seen some fifthwheels out of level by more than 6", so somebody is pushing the weight distribution on their axles!

[JRTJH]

Originally Posted by Pmedic4

Overall, it would seem the best answer to this is for someone to actually weigh the front and rear axles independently, raise the front of the fifthwheel 1", then 2" just to provide the corresponding information. Yes, it would be a great deal of work.

Honestly, I would be willing to bet 1" doesn't make a difference of more than 50-100 pounds, primarily based on the 'equalizer' of the axle mounting. Where it would probably show a difference is where you get 3" or more, which is beyond the range of the equalizer. Considering a 12,000 pound trailer, with 2,500 pounds on the hitch, the axles are still carrying 4,750 pounds each axle. I have seen some fifthwheels out of level by more than 6", so somebody is pushing the weight distribution on their axles!

When you take into consideration that the equalizer is the "fulcrum" (center point of rotation) and the pin on most fifth wheels is 20+ feet ahead of the "rotation point", lifting the trailer pin 6" may only lift the front axle 0.5" or even less.

You're right in stating that lifting the front of the trailer will "rotate at the fulcrum" and the weight will shift to the rear axle (somewhat). At "some theoretical point" the equalizer will "reach its maximum capacity".... I'd suggest that 6" elevation that occurs 20' ahead of the fulcrum will not equal 6" of equalizer shift. Probably more like 0.25-0.5 inches of "equalizer movement".