Reinforcing/stiffening a camper trailer frame

[climb.on]

We found a killer deal on a used 2020 single axle 20' camper. I'm looking to reinforce & stiffen up the frame. Camper overall is pretty cool, but I hate how light they made the frame (Lippert frame). I can feel it flexing when I tow it empty and I can flex the tongue (A-frame) 3/4" by just sanding on the coupler (i'm 195lbs). It will be pretty easy to drop the axle and stack & weld on 2x2 tubing under the existing frame and tongue. It would get me a little more clearance too. There are minimal components in the way, so it wouldn't be very hard and it would only add about 250-300#. There are lots of examples of these light frames causing water seal problems, door/window closing problems and slide-out alignment issues, because of all the flexing. Not to mention the very low safety factor if I overload, hit rough roads, or rust starts to weaken the steel. It just doesn't sit well with me.

The current main frame tubes are 2"x5" the tongue A-frame is 2"x4" and maybe 14 gauge. Amazingly, I don't think it's even 1/8" sidewall.

I'm trying to get a sense of the strength/stiffness that adding 2 x 2 tubing will give me...say 3/16 or maybe 1/4 sidewall. I've looked at some online strength & deflection calculators and it appears as though 2x7 rectangular tubing is about twice as stiff as 2x5 with the same sidewall. Is it fair to assume I'll at least cut the deflection in half by welding 2x2x3/16 to the bottom of the trailer frame?

 

[Old Man Roger]

I know I'm not seeing the whole picture, but assuming it has a c channel style frame, couldn't you just put the 2x2 in the existing frame? That's assuming it's not already boxed.

Boxing in a c channel style frame would add less weight, but it would be a little more labor intensive.

Maybe a gusset in each corner?

 

[climb.on]

I know I'm not seeing the whole picture, but assuming it has a c channel style frame, couldn't you just put the 2x2 in the existing frame? That's assuming it's not already boxed.

Boxing in a c channel style frame would add less weight, but it would be a little more labor intensive.

Maybe a gusset in each corner?

Not C channel, it's rectangular tube.

 

[Mr.N]

We found a killer deal on a used 2020 single axle 20' camper. I'm looking to reinforce & stiffen up the frame. Camper overall is pretty cool, but I hate how light they made the frame (Lippert frame).
...
2x2x3/16 to the bottom of the trailer frame

Yeah, i think you are on the wright track. Make sure to stitch weld.
Maybe do a 2x4 cross member or two or more. Heck add a hitch in the back for a bike rack
You could always add a bridge on the bottom too for additional support.

Double check the axle weight limit and weight the trailer loaded.

 

[climb.on]

Yeah, i think you are on the wright track. Make sure to stitch weld.
Maybe do a 2x4 cross member or two or more. Heck add a hitch in the back for a bike rack
You could always add a bridge on the bottom too for additional support.

Double check the axle weight limit and weight the trailer loaded.

Thanks. Yah my axle will definitely be the weak link after this.

 

[510ebl]

You are aware of Lippert’s historical issues with their frames requiring stiffening? Perhaps correspondence to the trailer manufacturer and frame manufacturer would net an engineered solution/warranty repair.

 

[climb.on]

You are aware of Lippert’s historical issues with their frames requiring stiffening? Perhaps correspondence to the trailer manufacturer and frame manufacturer would net an engineered solution/warranty repair.

Yes I am aware. Just google "Lippert frame issues." Many many hits on a variety of problems. This is a very simple frame. Whatever warranty it may have is not worth the hassle. Their warranty strategy is defer, deflect and deny. I'm betting the warranty doesn't transfer past the first owner anyway.

 

[Old Man Roger]

Yup! Sometimes it's just less hassle and stress to fix it yourself.

 

[510ebl]

Yes I am aware. Just google "Lippert frame issues." Many many hits on a variety of problems. This is a very simple frame. Whatever warranty it may have is not worth the hassle. Their warranty strategy is defer, deflect and deny. I'm betting the warranty doesn't transfer past the first owner anyway.

Ugh. Too bad they will likely not do the right thing.

 

[f150skidoo]

I think you have the right idea with welding tube to the bottom of the existing frame. But 2x2 1/4" wall is really overkill. I would just weld on 1/8" wall tubing to the bottom. It's kind of funny running into this thread today since this weekend I'm building a brand new frame for a 1976 air stream. Its amazing how poorly made the frames are on camper trailers.

 

[Bigblue&Goldie]

I think you have the right idea with welding tube to the bottom of the existing frame. But 2x2 1/4" wall is really overkill. I would just weld on 1/8" wall tubing to the bottom. It's kind of funny running into this thread today since this weekend I'm building a brand new frame for a 1976 air stream.

You should do a thread; curious what an Aairstream frame swap looks like.

 

[climb.on]

I think you have the right idea with welding tube to the bottom of the existing frame. But 2x2 1/4" wall is really overkill. I would just weld on 1/8" wall tubing to the bottom. It's kind of funny running into this thread today since this weekend I'm building a brand new frame for a 1976 air stream.

Thanks. I just don't have enough experience with steel fabrication to have a "feel" for strengths of various tubing.

Agreed...I want to see the AS frame swap!

 

[The Cobbler]

.......this weekend I'm building a brand new frame for a 1976 air stream.

You should do a thread; curious what an Aairstream frame swap looks like.

Yes, I vote for posts too, and no doubt, it will be prettier than the O.E. ever was

 

[Mr.N]

Thanks. Yah my axle will definitely be the weak link after this.

My experience show the tires..

 

[camaro77]

do not do 1/4 inch wall I would do 1/8 it will be plenty strong by time you get proper penetration for 1/4 inch steel you wont have much metal left from the factory frame rails. make sure before you start welding it all the factory frame is all level and square and everything on the camper opens and closes properly so you don't make more work for yourself.

 

[kerrynzl]

We found a killer deal on a used 2020 single axle 20' camper. I'm looking to reinforce & stiffen up the frame. Camper overall is pretty cool, but I hate how light they made the frame (Lippert frame). I can feel it flexing when I tow it empty and I can flex the tongue (A-frame) 3/4" by just sanding on the coupler (i'm 195lbs). It will be pretty easy to drop the axle and stack & weld on 2x2 tubing under the existing frame and tongue. It would get me a little more clearance too. There are minimal components in the way, so it wouldn't be very hard and it would only add about 250-300#. There are lots of examples of these light frames causing water seal problems, door/window closing problems and slide-out alignment issues, because of all the flexing. Not to mention the very low safety factor if I overload, hit rough roads, or rust starts to weaken the steel. It just doesn't sit well with me.

The current main frame tubes are 2"x5" the tongue A-frame is 2"x4" and maybe 14 gauge. Amazingly, I don't think it's even 1/8" sidewall.

I'm trying to get a sense of the strength/stiffness that adding 2 x 2 tubing will give me...say 3/16 or maybe 1/4 sidewall. I've looked at some online strength & deflection calculators and it appears as though 2x7 rectangular tubing is about twice as stiff as 2x5 with the same sidewall. Is it fair to assume I'll at least cut the deflection in half by welding 2x2x3/16 to the bottom of the trailer frame?

Photos would help! Is the frame flex "beaming" or "torsional"

If you are standing on the tongue. Put a jack under the hitch so the tow vehicle isn't bouncing.
I had a problem with a trailer "Flexing" It had a folded sheet steel tongue.
Everybody who checked it made the same conclusion.

I wedged a block of wood under the towball, and 2 blocks under the rockers off the suspension and jumped on it, and the problem wasn't there.

The problem was different spring "frequencies" between the tow vehicle and trailer causing a pitching momentum over the same bumps.

It was quite bad when empty and great when loaded.[I pulled a leaf out of each spring and the pitching went away]

Here is a photo [the tongue and main deck runners are made of folded 1/8" steel]
It weighed 370kg [814lbs] and was stable to tow when loaded
The Corvette racecar weighed 1180kg [2600lbs]

But I have towed a 2200kg [4800lb] Mitsubishi Pajero on it.
That trailer I built in 1998 and is still going strong [my friend now owns it]

With campers and enclosed trailers, the manufacturers don't need heavy "Built like a brick sh*t house" frames because the sides of the trailers become a stressed member .

 

[climb.on]

Photos would help! Is the frame flex "beaming" or "torsional"

If you are standing on the tongue. Put a jack under the hitch so the tow vehicle isn't bouncing.
I had a problem with a trailer "Flexing" It had a folded sheet steel tongue.
Everybody who checked it made the same conclusion.

I wedged a block of wood under the towball, and 2 blocks under the rockers off the suspension and jumped on it, and the problem wasn't there.

The problem was different spring "frequencies" between the tow vehicle and trailer causing a pitching momentum over the same bumps.

It was quite bad when empty and great when loaded.[I pulled a leaf out of each spring and the pitching went away]

Here is a photo [the tongue and main deck runners are made of folded 1/8" steel]
It weighed 370kg [814lbs] and was stable to tow when loaded
The Corvette racecar weighed 1180kg [2600lbs]

But I have towed a 2200kg [4800lb] Mitsubishi Pajero on it.
That trailer I built in 1998 and is still going strong [my friend now owns it]

With campers and enclosed trailers, the manufacturers don't need heavy "Built like a brick sh*t house" frames because the sides of the trailers become a stressed member .

More "beaming" id say. I think I found the culprit. Mainly its in the a-frame. When I block the header I can bounce on the a-frame and move it pretty well. I'm going to stiffen up the a-frame and header a bit and see how it goes. I kinda wanted to do that anyway for some extra gear I want to mount there. Your trailer references and loads are helpful - thanks.

 

[kerrynzl]

More "beaming" id say. I think I found the culprit. Mainly its in the a-frame. When I block the header I can bounce on the a-frame and move it pretty well. I'm going to stiffen up the a-frame and header a bit and see how it goes. I kinda wanted to do that anyway for some extra gear I want to mount there. Your trailer references and loads are helpful - thanks.

Is you A-frame "tongue" C channel or Rectangular Tube?
Does the A-frame pass under the frame or is it simply welded to the front cross-member?

You need to be very careful removing too much compliance out of a structure .you are basically moving it elsewhere [I did this with softer suspension]

If you have C channel , try and get another section of C channel folded up to slip inside to box it. [stitch weld it only]
C Channel has poor torsional strength and will try to twist if there is a lot of beaming loads on it [hence boxing it in]

What is the main frame made from? C channel, Angle, or Rectangular Tube?

Sometimes it is easier to cut the A-frame off and make a new one from Rectangular Tube.

Here is a trailer I built that had a 65mm x 35mm x 3mm RHS A-frame tongue [2.56" x 1.38" x 1/8"]
The A-frame was 1500mm [60"] long and didn't flex at all

In engineering "Shape is more important than Size"

 

[climb.on]

Is you A-frame "tongue" C channel or Rectangular Tube?
Does the A-frame pass under the frame or is it simply welded to the front cross-member?

You need to be very careful removing too much compliance out of a structure .you are basically moving it elsewhere [I did this with softer suspension]

If you have C channel , try and get another section of C channel folded up to slip inside to box it. [stitch weld it only]
C Channel has poor torsional strength and will try to twist if there is a lot of beaming loads on it [hence boxing it in]

What is the main frame made from? C channel, Angle, or Rectangular Tube?

Sometimes it is easier to cut the A-frame off and make a new one from Rectangular Tube.

Here is a trailer I built that had a 65mm x 35mm x 3mm RHS A-frame tongue [2.56" x 1.38" x 1/8"]
The A-frame was 1500mm [60"] long and didn't flex at all

In engineering "Shape is more important than Size"

A-frame is 2'x4'x1/8" rectangular tubing, that pass through the header and is welded to the inside of the main frame beams. The main frame beams are 2'x5'x1/8" rectangular tubing.

 

[kerrynzl]

A-frame is 2'x4'x1/8" rectangular tubing, that pass through the header and is welded to the inside of the main frame beams. The main frame beams are 2'x5'x1/8" rectangular tubing.

That shouldn't flex too much at all [unless it is made from Chinesium]

I've built a lot of trailers using [100 x 50 x 3mm RHS] which is 2'x4'x1/8" rectangular tubing.

what is the axle placement like? Americans builders prefer them too far rearward [the tongue weight myth, which puts the onus on the tow vehicle manufacturer.]

The other concern is the practice of welding sideways across the top of the RHS where it passes under or through the main frame.
This weld pinches when it cools and causes it to crack the A-frame. [you can get away with this weld if the front frame cross member is Angle or Channel and can twist easily. [see attached image]

 

[Broncoman75]

Bringing this thread back from the dead, I'm curious if the OP ever got this accomplished and how it turned out. I bought an Rpod that I knew needed some other repairs and when I got it home I discovered the frame was buckled right behind the axle. I know I could repair the frame rails with some gusset straps that span the weak area, but am considering sistering some additional tubing stich welded underneath the main frame either as an alternative, or as belt and suspenders...

 

[kerrynzl]

Bringing this thread back from the dead, I'm curious if the OP ever got this accomplished and how it turned out. I bought an Rpod that I knew needed some other repairs and when I got it home I discovered the frame was buckled right behind the axle. I know I could repair the frame rails with some gusset straps that span the weak area, but am considering sistering some additional tubing stich welded underneath the main frame either as an alternative, or as belt and suspenders...

Is that Beam Axles or Torsion Axles.
Try and get a body shop to pull the frame straight [they chain them to the floor and jack them]

Travel trailers are usually strong because beaming strength is helped by the side walls [unless it is "stick and tin"]
So you need to look for other areas that have come apart

 

[aShop]

The average life of a travel trailer is 10-12 years. You're halfway through that. How much effort do you want spend? You won't get paid for you effort when you sell.

Some trailers are lifetime purchases and they always hold their value and increase with good upgrafdes. Choose your brand wisely.