8ft SledDeck in a 6"6 Box Tips

[TKrebs]

Hey guys . Recently bought a used 8Ft marathon sled deck and installed it in my 2005 Gmc 2500 with 6"6box using bolts and square plates underneath with the nuts welded to them. Aswell I put 2 heavy duty wratchet straps on the front 2 eyelids for backup. When I don't have a load I seem to noticeable that the deck seems to shake a around a tiny bit when looking the the mirror. I put my sled on it today 163) and at the back the decks seems to be flexing when weight moves up and down and I also noticed more movement when looking in mirror with the sled on. All the bolts are tight. Just wondering if this is normal and if these decks are made to with stand all that? I'm pickin up a buddy's sled tommorw and heading out on a trip this weekend and am a bit nervous.

 

[wiseguy]

Ya, it was the same way when I had my Marathon. I also had the deck sitting on 6" risers. Bolted down on all 4 legs. Never had a problem with it though. Had a few times when you would look in the rear view mirror and it looked like the Quads where gonna get thrown off by how much the deck was moving.

 

[TKrebs]

So that is just normal?

 

[PBNFLD]

I have a 8ft Marathon in a short box dodge 2500 but I havnt had that problem. I have mine secured the same way, with 4 bolts and a strap just in case. I never noticed any movement in mine. Are your legs sitting on anything? like 3/4" plywood? I dunno if the bottom of your box is flexing. Marathon reccomends 3/4" plywood under the legs, squares around 15" x 18". I dunno what else to say, besides checking the bolts holding the deck together. Hope ya figure it out.

 

[OnlyPolaris]

The box of your truck is mounted by itself. So when you hit bumps the box will shake different then the frame/cab. It may look like the deck is shaking but it could be the hole box. it looks this way on my f-350 as well. But I have had ice around my legs from washing the truck. After driving over bumps and watching the deck shake the ice isn't even cracked and is intact. tells me the deck is not moving by itself.

 

[butters]

I had my deck bolted the same way. It actually wore through some of the box liner on the front of the box where the legs touched. No issues all last year though, no cracking, and the sleds didnt go for a rumble. The box does move alot compared to the cab.

 

[Bnorth]

Turnbuckle it from the deck structure as it will wobble when just mounted with the legs.

 

[muzbomb]

I got a 8ft deck in my F350 short box. I stacked 2 pieces of 2" thick rubber under my deck legs in the box and 4x6" metal plates 1"thick with grade 8 3\4" bolts with teflon locking nuts. Mine looks like it hasnt moved at all!! I have heard that using rubber in the box under legs may dent the box inside?? Mine looks good yet and i use my truck for work on lot of bumpy bush roads.

 

[medler]

Use the turnbuckles as well as the bolts. It's important I was told when I bought mine from cross Trax

 

[TKrebs]

Thanks guy. I did try plywood under the legs before i bolted it down, but i ended up cutting the pieces to small. So they sat uneven between the grooves in the bottom of my box. I guess ill have to cut them bigger and try it when i get back. Hopefully it holds together for a trip from edmonton to Valemount and back this weekend.

 

[Vaughn @ Marathon Decks]

Truck boxes flex a lot in relation to the cab:

Chevy Silverado vs Frod Superduty - Frame twist test - YouTube

The truck box also flexes a lot from front to back. All this movement is what breaks welds--make sure to check them. Also make sure that your cross bracing at the front of the deck is still intact.

 

[Pink-Inc]

I had a marathon that did the same. I had it bolted to the box on all 4 corners. With any weight on it at all it swayed when hitting bumps or making turns. Moved hat much it was hitting the box rails on either side.

 

[Marlon]

Marathon made a great deck, use turn buckle and chains, not rathcet straps. Also may want to beef up the extended part of the deck so it doesn't bend with the extra over hang.

 

[butters]

Funny thing, My 2011 dodge 3500 box is 74 inches.( 6 feet 2 inch) my marathon deck is getting modified to fit. (all i needed was maybe an inch and the tail gate would have closed) Had to run with no tail gate last year. Quite a jack around to get the deck to fit.