Converting a 4x8 Trailer to a 5x8 Deck Over With Wheels Under Platform

[Jwh92020]

I lucked into a 4x8 fully welded 2x2 tube trailer with a 2k lb axle for $100. I want to build it into a 5x8 with the wheels under the deck. I searched for pics, but apparently I'm not searching correct terms or something. Can any of you that have done a 5x8 "wheels under" build on a 4x8 please post some pics of your platform? It would be very helpful. Thank you.

 

[philpom]

I lucked into a 4x8 fully welded 2x2 tube trailer with a 2k lb axle for $100. I want to build it into a 5x8 with the wheels under the deck. I searched for pics, but apparently I'm not searching correct terms or something. Can any of you that have done a 5x8 "wheels under" build on a 4x8 please post some pics of your platform? It would be very helpful. Thank you.

Great deal on that trailer! I did exactly this except on a HF bolt together 4x8 2000 lb trailer. Here are some pics. If you have specific questions just ask.

Wiring runs on the floor, foam board insulation and puzzle mat like you see was layer in to make the entire floor flush with the shallow wheel wells.

It has now been on the road for 4 years, no issues. I put pockets in it as needed to get over bolt heads etc.

 

[philpom]

Additional photos. Many of these I took earlier today. Except a little dirt it's in great shape. Thousands of miles on it. Dry weight 900 lbs.

Wheel well was coated in tar.

Ignore my shoddy trailer light wiring, I was 2 years in and needed these for the first trip. One day I'll do them right.

 

[Jwh92020]

Additional photos. Many of these I took earlier today. Except a little dirt it's in great shape. Thousands of miles on it. Dry weight 900 lbs.

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Wheel well was coated in tar.
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Ignore my shoddy trailer light wiring, I was 2 years in and needed these for the first trip. One day I'll do them right.
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Thank you for all the pictures. Is the plywood directly on the frame 3/4"? Then 2x4s on the flat? What thickness is the 2nd sheet of plywood (the actual cabin floor)?

 

[philpom]

Thank you for all the pictures. Is the plywood directly on the frame 3/4"? Then 2x4s on the flat? What thickness is the 2nd sheet of plywood (the actual cabin floor)?

I think technically 13/16" ply, BCX pine. I used 2x3 wood for underneath. All contact with the steel frame is with to 2x3. From top down it's ply, 2x3, steel frame. Most of the pics are the bottom side up since I was prepping the surface. It's a single layer of ply. It took 2 4x8 sheets cut down to get the 5' width. I actually went a little wider for true 5' inside.

The cabin floor is the same sheet of wood top and bottom. I put the foam board plus puzzle mat over the top, nice on the knees.

 

[Jwh92020]

I think technically 13/16" ply, BCX pine. I used 2x3 wood for underneath. All contact with the steel frame is with to 2x3. From top down it's ply, 2x3, steel frame. Most of the pics are the bottom side up since I was prepping the surface. It's a single layer of ply. It took 2 4x8 sheets cut down to get the 5' width. I actually went a little wider for true 5' inside.

The cabin floor is the same sheet of wood top and bottom. I put the foam board plus puzzle mat over the top, nice on the knees.

Thanks for the clarification. I'm starting this build in about 2 weeks. I have a 6x8 I built for a guy that is on the short end of the punchlist. Building little trailers is way more fun than converting cargo trailers.

 

[Jwh92020]

Thanks for the clarification. I'm starting this build in about 2 weeks. I have a 6x8 I built for a guy that is on the short end of the punchlist. Building little trailers is way more fun than converting cargo trailers.

Great deal on that trailer! I did exactly this except on a HF bolt together 4x8 2000 lb trailer. Here are some pics. If you have specific questions just ask.

View attachment 2418747
Wiring runs on the floor, foam board insulation and puzzle mat like you see was layer in to make the entire floor flush with the shallow wheel wells.

View attachment 2418748
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It has now been on the road for 4 years, no issues. I put pockets in it as needed to get over bolt heads etc.

View attachment 2418757

I'm starting on this build. I have 2 3/4" from the top of the frame to the top of the tire. Even if I allow only 2 1/4" of travel for the axle (wheel well), that is a 5" build up under the cabin floor. That seems like a lot. I could do some under floor storage in the center of the cabin, but the rest is a lot of dead air space. I am replacing the existing 57/47 axle with a Dexter 61/46. I found scoring on the spindles and figured new is better than fixing old. I'll be in the trailer for $350, still not bad. With the new axle, I can get up to 52" of width between the tires (with the 57", there is 1" tire to frame each side. With the 61", there will be 3". I could get a 48" (RV full size) mattress in it. 2 not so "portly" folks could sleep on that. Thoughts on this whole thing? Thx

 

[philpom]

I would try and get as close to 60" wide as you can After using our for several years I think we'd feel pretty cramped. As it is now there is room to move around, sit in various places, stretch etc. At 48 I'd have to sleep basically up against a wall.

 

[Tony Latham]

With the new axle, I can get up to 52" of width between the tires

In my builds, they live and breathe on 5' x 5' Baltic birch plywood. That extra 2" would really cause me grief without adding any noticeable internal comfort.

Tony

 

[Jwh92020]

I would try and get as close to 60" wide as you can After using our for several years I think we'd feel pretty cramped. As it is now there is room to move around, sit in various places, stretch etc. At 48 I'd have to sleep basically up against a wall.

I ended up at 4.5x8, so a full size mattress will fit. I just posted a video in the Build Journal Forum.

 

[Jwh92020]

In my builds, they live and breathe on 5' x 5' Baltic birch plywood. That extra 2" would really cause me grief without adding any noticeable internal comfort.

Tony

I ended up at 4.5x8, so a full size mattress will fit. We'll see how the response is. Video is in the Build Journal Forum.