Installed 3" lift on fifthwheel today

[Roosters 67]

Well I bought a new truck, and the new one is three inches taller than the old. Pulled 550 miles with stock trailer height, weight of the trailer axles had a substantial difference, don't remember the weights exactly, but do recall that I was over on the rear axle by about 600Lbs. and was pushing near the tires limits. I only did this because I had no other choice at the time, had to move for work.

Enter the research, I did many Google searches for information on lift blocks, suspension modifications, taller springs, different hangers etc. In my research I found many interesting things, one of which is the idea of a full air ride suspension replacement. For now I have Installed a three inch lift, in the form of billit aluminum blocks. This method will induce greater torsional loads to the springs during braking and increased side loads during turns,increasing with the severity of the turn. This is understood and the suspension will be inspected more often and is only to be a "temporary" fix.

My plans involve building a replacement suspension system using Air ride technology to create the towing clearance needed, be able to lower trailer in campsite for better step access and stabilizer jack operation, and create a better,softer ride for trailer and contents. The suspension will always have equal load on each axle due to the front and back bags being tied together.

But this post is to show the installation of the three inch lift blocks.

Kind of self explanatory, old suspension showing factory set up, with 1/2 inch U-bolts. Next the block installed with the new 9/16 inch U-bolts which required opening up the holes in the spring plate for clearance. and lastly a picture of the beautiful blocks. also had to cut the excess U-bolt length after torquing the bolts down, handy 6 inch Metabo grinder with cut-off wheel made quick work of them.

Boy is that first step tall now! 6'5" to center of door handle from ground gonna have to build a step box!

When I build the replacement suspension system I will document and post that mod. I have to get time off at home first.

And don't mind the mess, just got done cleaning up after the hard work, had to shoot one so wife could see how high it is now, at 5'3" dont think she can reach handle from ground anymore. LOL

[Franka548]

Roosers 67,
Did you think about lowering the truck 3"? I put the air ride on the rear of my 03 Silverado, and lowered the back between 3 and 4 ", which leveled the truck and give me an acceptable ride height for my 5er.
Frank

[PushedAround]

Nice clean job. Raising a 5th wheel concerns me in that most of them seem to have a pretty high center of gravity as they come originally, and raising it, no matter how much you improve the suspension will not fix that. I think that I too would be looking for a way to lower my truck.

[Ted Lambert]

Because the spring bolts are the same size I wonder if the torsional stress will increase enough that the bolts might twist. Make sure you keep an eye on the tightness of the nuts.
Did you look at lowering the spring mounts? That would have kept the mounting dimensions standard for what the engineers designed the axle to do.
Just my thought.

[wandering1]

Originally Posted by Franka548

Roosers 67,
Did you think about lowering the truck 3"? I put the air ride on the rear of my 03 Silverado, and lowered the back between 3 and 4 ", which leveled the truck and give me an acceptable ride height for my 5er.
Frank

Smart way instead of ruining the center of gravity on the 5er.

[jesilvas]

I wouldn't like it that high, but that is a very clean install.

[TQ60]

Look into cross arm between axle and frame

Not sure what they are called but but raising the center of gravity is going to increase the latteral force on the axles greatly and things can get wonky...

Before you spend real money performing self engineering take itbto a place where they do thos for a living and consult them.

You may find that they can provide materials and ideas.

Your safety and that of the rest of us are at stake.

Have seen many "Redneck redo" jobs on the freeway with jacked up trucks done badly towing jacked up trailers done worse that look like roller skates on the road and the trailer does interesting things on curves and wind.

Would not look like a good drive to me at all.

You may look at taller tires on trailer to gain a little too...

[Roosters 67]

Thanks for the concern folks, this was not just done on a whim or as a permanent solution.

Originally Posted by Franka548

Roosers 67,
Did you think about lowering the truck 3"? I put the air ride on the rear of my 03 Silverado, and lowered the back between 3 and 4 ", which leveled the truck and give me an acceptable ride height for my 5er.
Frank

Frank, Yes that was a consideration, however taking a brand new(20K miles) truck and spending $3K plus on a kelderman air system is not an option. the truck is a factory 4x4 bone stock. I don't feel like chancing the warranty.

Originally Posted by narampa

Because the spring bolts are the same size I wonder if the torsional stress will increase enough that the bolts might twist. Make sure you keep an eye on the tightness of the nuts.
Did you look at lowering the spring mounts? That would have kept the mounting dimensions standard for what the engineers designed the axle to do.
Just my thought.

As I stated the suspension will be inspected often, for stresses and possible cracks, bends, etc. I replaced all the springs,and hardware upgrading all components less than 2K miles ago. I installed the Dexter E-Z flex system (fully greasable, with real bushings) and new springs. Moving the Spring hangers down is possible, however I am 1600 Miles from my welder and all of my shop equipment. As stated this is temporary in my situation.

Originally Posted by TQ60

Look into cross arm between axle and frame

Not sure what they are called but but raising the center of gravity is going to increase the latteral force on the axles greatly and things can get wonky...

Before you spend real money performing self engineering take itbto a place where they do thos for a living and consult them.

You may find that they can provide materials and ideas.

Your safety and that of the rest of us are at stake.

Have seen many "Redneck redo" jobs on the freeway with jacked up trucks done badly towing jacked up trailers done worse that look like roller skates on the road and the trailer does interesting things on curves and wind.

Would not look like a good drive to me at all.

You may look at taller tires on trailer to gain a little too...

Love the "Redneck redo" comment, truck is not jacked up, it is bone stock with bone stock tires. This was not the only option considered for making the trip home, just the most reasonable. All the options involve modifications to one or the other to some extent.

You are thinking of a "Panhard bar" to help locate the axles under the vehicle side to side it sounds like. A panhard bar will put more stresses into the springs and suspension system as a whole than without. Due to its design as it moves up and down it travels in an arc, and the working length from attachment points lengthen and shorten during suspension travel. This will cause the axles and springs to be pushed in both directions as the suspension moves up and down. they are designed for coil or air spring suspension systems with trailing arms or systems that do not provide lateral axle location in another way. The leaf spring is designed to locate the axle laterally. Bad Idea, would definitely be "Wonky"

As far as "taking it to a place that does those and consulting them" I assume you are referring to a suspension replacement system? I have been a fabricator and welder most of my life, also an Master ASE certified technician with much dealer training in suspensions and all vehicle systems. I have already discussed my plans with a good friend that is a mechanical engineer and he agreed to take my plans and do stress modeling on his fancy "puter program thingy" Believe me I have seen many a chopped up, half welded, poorly thought out, poorly executed vehicle modifications in my life. As far as doing anything to endanger my safety, my family's safety, or yours, believe me the new air ride system will be a much better arrangement as far as safety, capacity, align-ability, smoother ride and overall a more robust system than the existing spring system.

And trust me bigger tires were the first consideration, how ever with only 2.5" between the tires already, no room.

[TQ60]

Looks like you already have been "thinking" for some time.

Better to get nagged then reminded later after wrong things done.

Reason for consultation to trailer manufacturer is based on experience...

Took a 45 kw generator that was a factory built trailer system...the kind you see on the freeway down to a local well known manufacturer to look at building a compartment to secure the cords as they often were stolen.

The trailers were built with cg in wrong place and had a few other major issues.

We assumed some of the problems towing was just the 8500 weight but it seemed the F150 tow vehicles just were too light for the design of these where the F250 did not care.

The manufacturer would not touch them due to the poor design of the builder.

For yours a good trailer manufacturer or two may have ideas that you may wish to consider.

The trailer may need different things done that you may miss...no disrespect intended but unless you do this specific work a lot it is easy to miss things.

You seem plenty able to do the work and your enginner certianly is capable of running the calculations which is great but the manufacturer or trailer folks may be more aware of all of the options specific to your project so you can make the best choices.

[Roosters 67]

Originally Posted by TQ60

Looks like you already have been "thinking" for some time.

Better to get nagged then reminded later after wrong things done.

Reason for consultation to trailer manufacturer is based on experience...

For yours a good trailer manufacturer or two may have ideas that you may wish to consider.

The trailer may need different things done that you may miss...no disrespect intended but unless you do this specific work a lot it is easy to miss things.

You seem plenty able to do the work and your enginner certianly is capable of running the calculations which is great but the manufacturer or trailer folks may be more aware of all of the options specific to your project so you can make the best choices.

Tony, Thanks for all your input, no disrespect detected or taken.

I have been doing a lot of research. My design is patterned after both big rig trailer design, and rv/trailer air suspension designs. The fabrication portion is not a concern, after all I am responsible for welding process piping in refineries among other things, My welds are x-rayed often.

I also have been sourcing parts for the design. I plan on using Automotive style rubber insert bushings, eccentric bolts for align-ability, Medium duty truck sized air bags(for low air pressure/smooth ride). I found alot of good engineering information on both Goodyear and Continentals air spring websites. This endeavor is not just being entered into on a whim.

I plan on a sub-frame assy that will attach to the existing frame to give sturdy mounting points. This frame will also help spread the localized spring pressures caused by an axial spring compared to a leafs two points. Will have on board air compressor and tanks, along with automatic load leveling. I have scale readings from before, with 2x4 truck, 4x4 & trailer without lift, and will be scaling the truck/trailer as soon as I pull out headed home. I am confident my temporary fix will bring the axle weights back to where they should be, level the trailer in reference to road surface, and get the correct bed to overhang clearance.

As suggested, I will contact some of the manufacturers that do RV's on air ride chassis. Dont know if they will be conducive to sharing info, but worth a try. Any and all information available is always welcome when doing a project of this sort.

Suspension systems especially on trailers have not changed much in many years, It was amazing to see the wear on the old suspension components when I replaced the springs and hardware. they had about 30K miles on them, plum wore out. not just a little, but in BAD shape. That scares me a great deal thinking how many trailers with the same designs are going up and down the highways and byways. My design will reduce moving wear parts, and be very robust. tandem axle leaf spring setup have seven pivot points per side, my design will have two. Leaf springs fatigue over time (have had one break), rolling lobe air springs have a much longer lifespan.

I saw an interesting youtube video that a guy used a triangulated four link and airbags on his TT. His design was solid, looked like he used a kit designed for the aftermarket custom car scene. what I am planing will be more robust and a trialing arm design. I pull quite a few miles in a year for work and want a durable solid system.

Sorry to ramble on, but I get excited and very into new projects like I plan on under taking.


Spencer

[Cypressloser]

I don't want to comment or judge in either way, speaking of "Redneck redo" here is a pic of a 5th wheel I saw at a dealership in Red Deer, Alberta maybe a dozen years ago. (I did not take this pic)

[JEEPOHOLIC]

Originally Posted by Cypressloser

I don't want to comment or judge in either way, speaking of "Redneck redo" here is a pic of a 5th wheel I saw at a dealership in Red Deer, Alberta maybe a dozen years ago. (I did not take this pic)

awesome, I love the swinging seat under the fifth wheel, can you hear it, here hold my beer and watch this, lol

[PushedAround]

Originally Posted by Roosters 67

You are thinking of a "Panhard bar" to help locate the axles under the vehicle side to side it sounds like. A panhard bar will put more stresses into the springs and suspension system as a whole than without. Due to its design as it moves up and down it travels in an arc, and the working length from attachment points lengthen and shorten during suspension travel. This will cause the axles and springs to be pushed in both directions as the suspension moves up and down. they are designed for coil or air spring suspension systems with trailing arms or systems that do not provide lateral axle location in another way. The leaf spring is designed to locate the axle laterally. Bad Idea, would definitely be "Wonky"

If a panhard rod is installed properly, with the mid-point of the rod at the roll center, it would minimize the arc effect. Probably pretty hard to do on a trailer. That said, I would suggest a Watts linkage, which is specifically designed to allow vertical movement with no lateral or arc movement whatsoever.

[Roosters 67]

Originally Posted by PushedAround

If a panhard rod is installed properly, with the mid-point of the rod at the roll center, it would minimize the arc effect. Probably pretty hard to do on a trailer. That said, I would suggest a Watts linkage, which is specifically designed to allow vertical movement with no lateral or arc movement whatsoever.

PushedAround, You are correct on all, also would be possible to install a panhard bar approaching 5'6" long. As I am sure you know the longer the rod, will also reduce the arc. But the panhard will still induce side movement during suspension deflection.

The Watts link would be the best choice in this instance, would remove all side to side loading and travel and not interfere with the spring operation. However the cost and space allowed makes a Watts link undesirable, I also would have to install crossmembers able to take the load. Not to mention that this is temporary. Only for getting 1600 miles down the road to the house. The suspension will be upgraded to the air ride design.