5th Wheel leveling question

[tschwab]

Just hooked up the new 5vr and I have about 8" bed rail clearance. From a visual standpoint it looks level, but when I look at the level, it is slightly off sitting a little high in the front, by I'm guessing 2". I can drop the hitch in the bed down by one notch, would this sit the front of the 5vr too low or put too much weight in the bed? Is it best to have as much weight in the bed over the axles as possible while still maintaining levelness?



I guess the question would be a little high in front or a little lower in front, what is best if you can't get it exactly level?

 

[JPudenz]

I had to play with mine to get it as close to level as possible. I would suggest you look at the pin box adjustments and the 5th wheel hitch adjustments as one may give you a smaller adjustment than the other. The biggest concerns of course with not being level is ride and tire wear.



As far as which is the better of two evils, I would always go the direction that will give you better clearence, high in the front.



JJ

 

[RustyJC]

Let's not forget that tandem axle 5th wheels generally use equalizers in the suspension between the axles - there are exceptions where the 5th wheels have various independent suspension systems. 2" front high is certainly within the working capacity of the equalizers to handle.



Rusty

 

[Cryppie]

The first place I would head is to a scale. Find out what your truck and trailer weigh separately, then hook up and calculate your pin weight. 15-20% of your trailer weight is normal (klenger can correct me if I'm wrong ), and as long as you're in that range I wouldn't be too concerned about it, 2" high in front shouldn't put too much additional weight on your rear axle, but you could also figure that out while you're on the scale as well. The general rule of thumb is trailer high means less pin weight. On my new enclosed car hauler I had to drop my hitch as far as it would go and raise the pin all the way to get the trailer level, and still I have about 8" clearance. Play with it until you're happy with how it looks and rides, good luck!

 

[Ron Bissett]

level the levelW

When hooked up on level ground like a hard top drive way or parking lot with out a lot of slope ,if the rig looks level that should be good to go , if not measure the front bottom to ground of the frame and the back see if they match if so, good to go. The level you speak of. I get picture of one stuck on the trailer ,it may not be level, with the bottem of the trailer, off set needes to be corrected, or accounted fore , Droping the hitch on an Reese, will cause a two inch drop in the pin of the trailer. As others state wight it first then decide what to do . Ron Bissett In metro Louisville KY :-laf

 

[CLAYTON]

Let's not forget that tandem axle 5th wheels generally use equalizers in the suspension between the axles - there are exceptions where the 5th wheels have various independent suspension systems. 2" front high is certainly within the working capacity of the equalizers to handle.

Rusty... about how much play is there with equalizers. Granted each trailer will be different.

 

[RustyJC]

I guess I don't understand the "how much play" question. Do you mean how much clearance exists between the bushings (spring and equalizer) and bolts? Or do you mean how much of an "out of level" condition can the equalizers compensate for?



For those who may not be familiar with them, let's review how the equalizer works. If you look on page 4 of 18 at the tandem (dual) axle illustration HERE on Dexter's website, you'll see that the front of the front axle spring and the rear of the rear axle spring are securely fastened to the chassis. The rear of the front axle spring and the front of the rear axle springs are attached to shackles, just like the rear of the rear axle leaf springs on our trucks. The difference is that these shackles are then attached to an equalizer link that pivots off the frame.



In the 2" front high situation described, raising the front of the trailer tends to move weight onto the rear axle. As the rear axle carries more weight, however, the equalizing link will pivot up at its rear side (as viewed in the illustration) since the rear of the link is now carrying more weight than the front side. As it pivots, it pulls the rear end of the front axle spring downward, forcing more weight onto the front axle. The equalizing link will stop pivoting when the forces on both ends of it are equal.



Therefore, until they run out of travel, the equalizing links will balance the weight carried by each of the tandem axles.



Rusty

 

[CLAYTON]

I guess I don't understand the "how much play" question. Do you mean how much clearance exists between the bushings (spring and equalizer) and bolts? Or do you mean how much of an "out of level" condition can the equalizers compensate for?



For those who may not be familiar with them, let's review how the equalizer works. If you look on page 4 of 18 at the tandem (dual) axle illustration HERE on Dexter's website, you'll see that the front of the front axle spring and the rear of the rear axle spring are securely fastened to the chassis. The rear of the front axle spring and the front of the rear axle springs are attached to shackles, just like the rear of the rear axle leaf springs on our trucks. The difference is that these shackles are then attached to an equalizer link that pivots off the frame.



In the 2" front high situation described, raising the front of the trailer tends to move weight onto the rear axle. As the rear axle carries more weight, however, the equalizing link will pivot up at its rear side (as viewed in the illustration) since the rear of the link is now carrying more weight than the front side. As it pivots, it pulls the rear end of the front axle spring downward, forcing more weight onto the front axle. The equalizing link will stop pivoting when the forces on both ends of it are equal.



Therefore, until they run out of travel, the equalizing links will balance the weight carried by each of the tandem axles.



Rusty

You said that that 2" should be "within the working capacity of the equalizers to handle. " So I was wondering how much "play" / "working capacity" the equalizers can handle. So if the front of the trailer was 4" higher instead of 2" higher then the back of the trailer would this be within the "working capacity of the equalizers"? So basically what range of motion or height difference from the front of the trailer to the back of the trailer can there be before the axles take unequal weight?

 

[RustyJC]

Therefore, until they run out of travel, the equalizing links will balance the weight carried by each of the tandem axles.

The highlighted area above is the operative limit of the equalizer link's capabilities. I personally wouldn't want to run them at that extreme travel, however, as they're designed to float. You don't want the spring eye hitting the frame mount, equalizer link, etc.



Rusty

 

[CLAYTON]

Ahh I see... thanks

 

[Ron Bissett]

The highlighted area above is the operative limit of the equalizer link's capabilities. I personally wouldn't want to run them at that extreme travel, however, as they're designed to float. You don't want the spring eye hitting the frame mount, equalizer link, etc.



Rusty

I think that most springs are not pined on both ends ,the end is allowed to extend through a slot to keep from bending and will return to its normal position (spring pressure upward) also their are in most cases bumper stops over the center of axle travel about four inches of travel is normal ,when axles are placed over the springs stops must also be elongated to keep this travel distance. The action of the equalizer is to tranfer wight over bumps and holes while moving and return to normal center of axle area directly under the stopes. Ron Bissett in Metro Louisville Ky

 

[RustyJC]

I think that most springs are not pined on both ends ,the end is allowed to extend through a slot to keep from bending and will return to its normal position (spring pressure upward) also their are in most cases bumper stops over the center of axle travel about four inches of travel is normal ,when axles are placed over the springs stops must also be elongated to keep this travel distance.

Dexter supplies both double-eye and slipper leaf springs. The illustration and functional description I provided applies to double-eye springs as shown.

The action of the equalizer is to tranfer wight over bumps and holes while moving and return to normal center of axle area directly under the stops.

Yes, it does that, but if unequal static loading as I described is applied to the equalizer link, it will pivot until the loads are equalized. Think about it - if unequal dynamic forces will make it pivot, then unequal static forces will also make it pivot.



Rusty

 

[Ron Bissett]

You are right , but as said and could have stated on the lower end of the price line that most of us deal in that open end is for the most prevelent. I have had one leafe come out of the end going over a curb on way out of a parking area had to chain up the spring to travle about half mile then jack up the axle and reposition the spring that was back a few years and have hade no problem with the spring or axle. I hope I haven't misguided any one ,just adding my two cents worth. Ron Bissett entry level over fifty years ;;;In Metro Louisville KY

 

[FCecelin]

shouldn't change weight at all so drop pin box one hole . . make sure you will have enough clearance between pickup box top and bottom of FW.

 

[TRAMPLINEMAN]

tschwab, leveling is important, but as FCecelin stated, making sure you have enough clearance between pickup bed rails and 5th wheel is just as important. If the trailer is too close to the truck it will crush the bed rails when going thru deep dips in the road, pulling into some fuel stations and backing into some rv spaces for example. Keep that in mind while adjusting. Good luck.

 

[surfbeetle]

The manual on mine says to have the trailer level or one inch lower at the front. Then it also says to have 6 inches of clearance between the trailer and the bed rails, more for off road applications. I had to have my axles put under the leaf springs on the trailer to level everything and have 6 inches of clearance.

 

[NIsaacs]

If you have 8" of bed rail clearance, I would leave it alone. Two inches high in about 30' is very little. I am not sure how the pin weight will change with the trailer being level, 2" high or 2" lower. With equalizer's, the weight will change zip, none. If the trailer has independent axles and the front is 2" high, you will actually have more weight on the pin not less. However, again, with 2", in say 20 feet from pin to center of the trailer axles, not much weight change. One good reason to have the trailer level or slightly lower in front, is wind resistance and tailend to ground cearance.





"NICK"

 

[tschwab]

If you have 8" of bed rail clearance, I would leave it alone. Two inches high in about 30' is very little. I am not sure how the pin weight will change with the trailer being level, 2" high or 2" lower. With equalizer's, the weight will change zip, none. If the trailer has independent axles and the front is 2" high, you will actually have more weight on the pin not less. However, again, with 2", in say 20 feet from pin to center of the trailer axles, not much weight change. One good reason to have the trailer level or slightly lower in front, is wind resistance and tailend to ground cearance.





"NICK"

Nick, how would I know if it has independent axles?



Everyone - Thanks for all the great replys.

 

[JimKing]

Interesting that not many folks are advocating a weigh-in before you contemplate making any adjustments. Getting the weight right is as important as getting the height set, maybe more so. Many folks are operating rigs, that are nice and level, without any knowledge of the actual weight or distribution of their setup. You can have a perfectly level setup and be dangerously unbalanced without knowing WHERE your weight is located. Load it up, fill your tanks and get it weighed before you make any decision to raise or lower.