Wilson Fontaine or doonan combo step decks

Pictures

 

Doonans j track is a simple fix. Kelly zecha has admitted it's a problem. I been emailing back and forth with them about my repair. Cost me 165.00 in materials and 2 hours worth of work.

 

Can you school me on what exactly you did there.? Looks good, & I'd like to try & fit mine the same way..

It that a spacer of some kind? And looks like you have the bolt head the opposite way, instead of just the threaded end sticking up. Nice..

 

I bought a 1/2" thick by 7/8" thick diameter spacer with a 3/8" ID. It's a steel spacer, and then I bought a 3/8" zinc coated flange bolt and zinc coated nylon insert flange locknut. It takes 94 spacers and bolts to do a 53" stepdeck with 14" crossmember spacing. 12" crossmembers would be little over 100. I did every bolt in my tie down track including the vertical ones in the neck. I chose the flange bolts so I didn't have to worry about washer thickness and as you can see the bolt flange is close in size to the spacer. I got the bolts from McMaster Carr, I'll get a length when I'm at my shop again. If you do a bolt and nut setup, you need to know your thicknesses before you buy. I have about a 1/16" clearance below the floor. But I'm below and that is what matters.

From the factory Doonan uses stainless bolts for looks only. I asked Kelly at doonan his thoughts and he highly recommend the grade 8 bolts if your ok with steel bolts. Stainless steel 3/8" bolts have a tensile strength of 70k psi, where a grade 8 is 150k. The bolts are going down through the floor into the crossmembers with the nut on the bottom so that I could keep it below the floor. This method keeps it below the floor so nothing will catch it. If I put the nut on top the bolt will stick up above the floor. Kelly expressed that it doesn't matter what direction the bolts going as long as it's tight and below the floor.

You shouldn't use any bigger spacers then I have simply cause the spacers won't fit. The 7/8" spacers can go into the rail standing up and will pivot with just enough space to lay over. Anything bigger won't layover without some grinding.

If you buy what I bought you won't need to do any modifying. I used a 1/2" impact on top and a wrench underneath for removal. The wife ran the impact, I held the wrench, we did 3-4 at a time. We then tightened them with a 3/8" impact cause doonan has a torque spec on them bolts and a half inch will exceed the torque and break bolts. It took us 2 hours cause we had to move bridges and tarps.

Here is a link to the spacers hopefully the link works.

AA-648-A Steel Bushing, 7/8" OD, 3/8" ID

I'll get you links to bolts and nuts also. I should start charging for this since doonan may entertain my modification as well .

 

Stainless on aluminum is not exclusively for looks, look into corrosion between aluminum and steel (and zinc), black grade 8 might have been a better long term solution, stainless is pricey I understand and is also more brittle, but there's a good reason for it when it's going to touch aluminum

 

Let me get this straight. I give the explanation for my reasoning and what I did to help someone else and your going to school me on what I did wrong? Is that correct? So stainless steel would be the best option being the tensile strength is half of grade 8. Ya know what. I ain't got time for this ####. There is also a reason that stainless and aluminum corrode more then any 2 dissimilar materials. In a dry salt free environment, best option, stainless fasteners if you don't need strength. In a road truck where strength is an option, grade 8, and zinc coated to slow the discoloration is the only reason.

 

I took a minute to double check my facts and I'm correct in my findings. The zinc coating creates a layer between the fastener and the aluminum material slowing down the corrosion. Where the stainless steel creates galvanic corrosion from 2 dissimilar materials. With a barrier between the 2 materials it can slow the corrosion down of stainless and aluminum. My facts and my feedback from suppliers and manufacturers are that stainless has its place. And it's not on an aluminum trailer that sees the elements.

Furthermore, when I put 60-70k lbs on the deck and chain it down. It's really something when you can watch a stainless steel bolt bend cause it's so soft, but you can reef down and not even phase the grade 8. Pretty isn't always practical.

 

I put in my two cents on why another option though pricey was a better choice, it's not that your fix was bad, but I don't think it's a great idea to recommend zinc coating because it may slow discoloration but structurally compromises things faster than a black oxide grade 8 and far faster than stainless. The corrosion is called galvanic, key ingredient in galvanization is .... Zinc

Tensile strength is not the only thing that matters here either, look at the forces that will be hitting that bolt, grade 8 is absolutely stronger but at a 3/8 diameter what you're dealing with is shear force and 70k psi turns out to be a crapton more than necessary (apologies for the lack of precision) especially since what's hitting it is aluminum which will deform first

My experience in this comes from designing fabricating and installing wastewater treatment stairs and railing. Your solution absolutely will work and probably have absolutely no problems for at least 5 years, but it is not the *best* option out there when you start looking at 10 to 20 year timescales. If that's fine for you, fine, if that's helpful for others, fine, I voiced a concern on the basis that more information is better than less, I'm not attacking you, not your suggestion, none of that