Hello all, I know there have been many posts of getting your truck and trailer to ride level but right now I'm stumped. I have a 16 ram 2500 long bed diesel and a 16 forest river wildcat maxx 5er 242rlx. As we speak now my trailer when hooked up to truck is 7" higher in the front then the rear. Bed rail clearance is 7" closest to the cab of the truck and 5" at the end of the bed. My axles came flipped from the factory, pin box can't be adjusted any lower and hitch in bed is as low as it can go. What do I do?

Npt totally uncommon. Unless your spring hangers have adjusting holes your only solution might be to add a sub frame.

Stupid question but what would that entail exactly?

Fabeicating, welding, jacking, bolting. Im not trying to be a smart A@@, but to do it correctly you need to support the trailer, remove all of the running gear, cut off the spring hangers, weld a piece of 4X4 box tubing to the frame. Install all new spring hangers, reinstal the running gear. This is normally NOT a DIY project since it requires a lot of fitting, and welding and precise measurements to ensure the trailer tracks true when done. So first I would crawl under and have a good look. See if there are additional holes in the spring hangers. Mine had them, so it was pretty eady to raise mine 2 inches at the axles.

Can spacers be safely added between the axles and springs?Can taller tires be installed?

My 08 GMC is stock and I have the exact same issue, axles already flipped. I don't get how low they are now. Mine is at the dealer now seeing if they can add a couple inches to the springs to get it close to level.

Getting 5er and truck level with each other. | Good Sam Community

30 Replies

N-Trouble
Explorer
Aug 09, 2017
2001400ex wrote:
mkirsch wrote:
The trailers aren't lower. The trucks are taller.

My pickup is an 08. Fifth wheel is 17.

HD trucks have been getting taller for some time now. The RV manufacturers are necessarily making the changes needed to adapt to newer TVs. Seems like all to regular of an occurance of owners having to lift their 5er. Seems to be the norm rather than the exception.
Reddog1
Explorer II
Aug 08, 2017
I will have to ponder whether or not I will install a Panhard. The bracing I have from the spring hangers inboard to the frame cross members have that pretty secure. I have new bushings in all springs and related. The shackles are pretty short, and not worm. I am sure I have some twisting in the springs, but question on a flat highway twisting of the springs would cause the rear of the trailer to whip. The more I think about it, the more convinced I am it is a weight distribution. On my last camping trip, I measured several other 5th wheels from ground to frame. They were within an inch of mine, some higher and some lower.

I appreciate your input, and will decide where I go from here.

Wayne
BenK
Explorer
Aug 08, 2017
Forgot to mention the most important point on this image

Notice the pivot point vertical line vs the CG vertical line...vertical in reference to the ground (edit)

As the CG is moved up (lift)...it comes closer and closer to the pivot line...when it touches that pivot line or gets too close...it will tip over...or more easily

There are more things happening with a tired vehicle and that is tire sidewall roll over, slip angle and more stuff.

This all focuses the forces on the outside suspension area.

Not going to break stuff instantly, but lessens the longevity and of course the tip over potential a greater potential
BenK
Explorer
Aug 08, 2017
Reddog1 wrote:
BenK, I have read your response to my post a couple of times. There is nothing I take exception to. I do not see any photos or sketches. I did not follow the " Reference my broom handle & bar weight example" statement.

Used verbiage...no diagrams back then.

Trying to say that with a higher CG...the forces are amplified by the increased lever arm of the lift amount....that will then focused at the suspension joints...that then moves that force to pavement via tires

Found some images that might help...

Locomotive, but CG applies to all things. This one on rails, so no tire slippage or higher slip angles. The higher the CG the greater the forces and high chances of tipping over

This one is of an off roader (nephew had a 8" lifted Samurai and constantly broke leaf spring eye bolts & mangled their home made shackles...till he asked me for help). The Centrifugal force is the same, but if you lift (increase the lever arm), that same centrifugal force has more effect...my attempt with verbiage with the broom stick and 5 lb weight swung around to show that your wrist will take much more force to hold it vertical with a higher CG

Higher CG is a common item taught/discussed in most ME classes and this is just an image from a college class work

There are too many more and hope this helps

I have a Suzuki Samurai I modified for offroad use. It is lifted 6-1/2" and has soft leaf springs. The Panhard Bar was an exceptional improvement to its road manors. Most offroaders will say you do not need a Panhard with leaf springs.

Ditto that on my nephews Samurai. His buddy didn't understand and their first attempt had a home made panhard bar too short and not enough tensile strength. Told them to either buy one or go to a junk yard Mustang. They found one old Mustang and it was just right.

Back to the why...a lift has the longer lever arm and muscles the lower suspension...that the OEM designed it for less lever arm.

By installing that panhard rod, it took most of the lateral forces onto more solid areas of the body/frame and suspension.

Showed them HOW2 replace the leaf spring eye bushing with a home made delrin bushing that had a larger hole for a larger grade 8 bolt

Where would you locate the Panhard on my 5th wheel?

First, longest that will fit.

Frame rail on one side and on the axle at the other side.

There will need to be a connecting rod at both ends to make the panhard rod level in a static mode. The length of those end connection rods need to be long enough to articulate without allowing the panhard rod to touch/strike anything in both compression and extension of the trailer suspension movement range.

But...maybe no panhard rod needed if you don't drive HARD. Maybe just beefing up the shackle and leaf eye areas would be enough, but that is up to you, as I don't know how you drive...where you drive, etc

Plus...am NOT a fan of ever increasing CG on anything vehicle related...have done it, but only after noodling it...then re-noodling it a lot...
Reddog1
Explorer II
Aug 08, 2017
BenK, I have read your response to my post a couple of times. There is nothing I take exception to. I do not see any photos or sketches. I did not follow the " Reference my broom handle & bar weight example" statement.

I have a Suzuki Samurai I modified for offroad use. It is lifted 6-1/2" and has soft leaf springs. The Panhard Bar was an exceptional improvement to its road manors. Most offroaders will say you do not need a Panhard with leaf springs.

Where would you locate the Panhard on my 5th wheel?
BenK
Explorer
Aug 08, 2017
Reddog1 wrote:
I have searched for causes of sway and fishtail with 5th wheels. Over and over again I read "... the fifth-wheel hitch pin is centered over the axle, unable to move laterally, which makes the fifth wheel trailer virtually immune to this motion." It beats me how someone could make that statement.

Ditto and think lost to them is the fact that the fiver pivot/mounting point is either dead centered on the TV's rear axle center line, or inches either forward or rearward of the TV rear axle center line

Meaning, zero lever arm or inches long lever arm vs a tongued trailer ball is tens of inches to several feet away from the TV's rear axle center line...meaning a much longer lever arm for any trailer sway to leverage the TV's rear end

Why PullRite was such a GREAT anti-sway WD Hitch system, but it was too heavy, added too much to under-hang (ground clearance), could NOT remove a spare tire underneath there, etc....or the current claimed best/better HA or Pro, as it projects that pivot point closer to the TV's rear axle center line. Thereby reduced lever arm length

So all trailers can and do sway...those with longer lever arms affect the TV much more.

As long as the TV is pulling and the trailer has drag...the lever arm forces are not able to do much to a TV towing a Fiver...why when a tongued trailer starts to sway...the best thing to do is to touch the trailer brake controllers manual lever...to increase trailer drag while the TV continues to pull

I also read tongue/pin weight should be more than 10% of the trailer weight. We are very limited on just how much we can do to change the pin weight on a 19 foot 5th wheel. I can't find my weight notes, but as I recall the pin weight is only 320 lbs. The trailer is 5060 lbs which should have a minimum of 500 lbs (10% percent). I think I did remove about 150 lbs from the box in the rear of the trailer, which should be the same as adding 150 to the pin. If true, I should now have about 650 lbs. I think this is borderline.

Agree, but...again that shorter lever arm of a Fiver will have less to little affect on the TV's rear axle

Tires can have an impact on sway and fishtail. As I previously stated, the OEM tires were P215/75R15. I installed GOODYEAR MARATHON ST225/75R15D. I really don't think tires are my problem.

Agree and add that, that is more important (or of higher impact) on the TV than when on the trailer

BenK suggested adding a Panhard Bar. I have experience with Panhard Bars for automotive applications, but not trailers. I have found no information for this application but I am open for discussion.

Because trailer OEMs, generally, are into "cheapest" for stuff not visible to the general buyer. How many look down there and if they did...would know what the heck about the stuff down there...

But...there is little difference in lateral (side to side loading) on a leaf spring setup between a TV with leaf spring rear suspension and a trailer with leaf spring suspension. Loading and dynamics same/similar and if lifted...exacerbated by longer lever arms and mainly focused at the shackles & leaf eye bolt(s)

A panhard rod (AKA bar) locates the axle in reference to the trailer in this case.

By doing so, it takes away most of lateral forces that would have gone to the leaf spring suspension components. Mainly the shackle and leaf eye bolt. Reference my broom handle & bar weight example

BenK also suggested shocks. For years I have observed trailers of different types, including RVs, may or may not have shocks. I do find them more often on high end trailers. I have read high psi in tires stiffen the sidewalls, but also tend to make the tires bounce. The shocks dampen the bounce. There is very little if any effect on sway of truck Campers in my experience, could be different with 5th wheels, I am open for discussion.

Again...IMHO, trailer OEMs go cheap and your comment that the high end trailers do have shocks...almost self explanatory. Or consider removing the shocks on your TV and then see how it handles...

Consider this...a tire bouncing means that while it is 'off pavement'...there is no control. No contact means no braking, cornering, etc...it is flying...

At this point, I think my 5th wheel was designed for a 1/2 ton truck in 1988, with a minimum amount of pin weight. I see my only option is to do some fabrication work, such as a spare tire mount above the pin, and maybe move the propane bottles to the front. I think that would add about 150 lbs to the pin and remove about 100 lbs from the rear. That would give me about 800 lbs total pin weight plus the removal of about 250 from the rear.

I am open for suggestions or comments. Links to shock and/or Panhard install or discussion would be appreciated.

Wayne
Reddog1
Explorer II
Aug 07, 2017
I have searched for causes of sway and fishtail with 5th wheels. Over and over again I read "... the fifth-wheel hitch pin is centered over the axle, unable to move laterally, which makes the fifth wheel trailer virtually immune to this motion." It beats me how someone could make that statement.

I also read tongue/pin weight should be more than 10% of the trailer weight. We are very limited on just how much we can do to change the pin weight on a 19 foot 5th wheel. I can't find my weight notes, but as I recall the pin weight is only 320 lbs. The trailer is 5060 lbs which should have a minimum of 500 lbs (10% percent). I think I did remove about 150 lbs from the box in the rear of the trailer, which should be the same as adding 150 to the pin. If true, I should now have about 650 lbs. I think this is borderline.

Tires can have an impact on sway and fishtail. As I previously stated, the OEM tires were P215/75R15. I installed GOODYEAR MARATHON ST225/75R15D. I really don't think tires are my problem.

BenK suggested adding a Panhard Bar. I have experience with Panhard Bars for automotive applications, but not trailers. I have found no information for this application but I am open for discussion.

BenK also suggested shocks. For years I have observed trailers of different types, including RVs, may or may not have shocks. I do find them more often on high end trailers. I have read high psi in tires stiffen the sidewalls, but also tend to make the tires bounce. The shocks dampen the bounce. There is very little if any effect on sway of truck Campers in my experience, could be different with 5th wheels, I am open for discussion.

At this point, I think my 5th wheel was designed for a 1/2 ton truck in 1988, with a minimum amount of pin weight. I see my only option is to do some fabrication work, such as a spare tire mount above the pin, and maybe move the propane bottles to the front. I think that would add about 150 lbs to the pin and remove about 100 lbs from the rear. That would give me about 800 lbs total pin weight plus the removal of about 250 from the rear.

I am open for suggestions or comments. Links to shock and/or Panhard install or discussion would be appreciated.

Wayne
BenK
Explorer
Aug 07, 2017
First...it is a suspension "system" designed, certified and warranted by the OEM...for as is from the factory. Changing that requires some re-engineering...serious re-engineering. Gotta add at this point that all things engineered/designed are NOT for the good days, but for the worst day out there when Mr Murphy crosses your path...either it right spot on then, or not. Key is to be able to manhandle that situation

So in lifting the box/frame higher on the suspension, it will increase the loading during curves/turns/etc on the suspension. Mainly the shackles and bolts to it

A pan-hard rod will help reduce the amount of lateral (horizontal, side-to-side) movement and will do little to nothing for the lean that will come with an increased CG

For those who might not understand what a higher CG will do...take a broom stick of about 3 feet long. Slide a 5 lb weight on it with the broomstick poking through the middle hole

Tape it about 1 foot from your hand and lean it off vertical. Note the amount of wrist/arm strength to manage that

Then slide the weight higher to end, about 3 foot from your hand. Tape it on and then lean it off vertical and note the amount of hand/arm strength it will take doing that.

Then do that while running around a circle where centrifugal forces will increase the above forces needed to to manage that.

Now with a trailer box & frame weighing in the thousands of pounds...that force is going to very high

The pan-hard rod will keep the side-to-side movement of the box/frame from moving side-to-side much. How much is dependent on the compliant bushings used and the length of the rod and where it is attached to the axle and frame.

But...there will still be added loading on the outside suspension and mainly on the shackle(s). On that, the bolt will be in shear and the amount of loading muted by the leaf eye bushing

As a min on that, the shackle should be re-enforced. Best to have one that has a member between the two and the shackle thickness should likewise be re-enforced by either thicker and/or a bend-back

The bolts should be increased in size, but the leaf eye most likely will limit that. So a min of a grade 8 (English) or grade 8.2 (metric) with same grade washers on both sides. Ditto the nut, but hardened nuts tough to find (pun intended)

Adding a properly designed pan-hard bar can also allow consideration of removing the leaf springs for a coil spring setup...but...will require additional links and is now very complex for a trailer...

An anti-lean bar (AKA...anti-sway bar) will help, but note that it will load up the outside tire/suspension even more. Snap transition from chirping tires to full out skid can make for a tough trailer to handle at the limits

Shocks will help in all that, but not a total solution. Depends on the shock type and not many will put in high end shocks with smart valving. Finding one that has the proper "Z" length and extension length will be tough
BarneyS
Nomad
Aug 07, 2017
Reddog1 wrote:
BenK wrote:
If going to all that work raising the CG in the process...suggest adding a pan-hard rod to the trailer suspension as a min. Shocks too
I wanted to ask about a Pan Hard Bar and Shocks, but I thought it might be considered a hijack of the thread. Perhaps Jbtownsend101 will okay expanding this discussion?

Wayne

I say go ahead and discuss it. In my opinion it is all part of the process of getting the trailer level with the truck that is towing it. I certainly am not going to step in unless you guys start calling each other names! :E
Barney
Reddog1
Explorer II
Aug 07, 2017
BenK wrote:
If going to all that work raising the CG in the process...suggest adding a pan-hard rod to the trailer suspension as a min. Shocks too
I wanted to ask about a Pan Hard Bar and Shocks, but I thought it might be considered a hijack of the thread. Perhaps Jbtownsend101 will okay expanding this discussion?

Wayne