Wilson finalized the design of the stepdeck, to be built on July 19th-25th. With a 10' upper deck and 24" kingpin position, it has 76" distance from the kingpin to the front part of the landing gear. They did a weight distribution analysis and said the best fifth wheel position for my truck will be 4" ahead of the center between the drive axles. Now, I measure the distance from the center of the fifth wheel IN THIS POSITION to the farthest point on my mudflap and after 2 measurements on both sides, it's official: the trailer would barely miss the mudflaps on a sharp turn - the truck has 76" from the fifth wheel to its mudlflap. So, either I keep the fifth wheel right between the drive wheels (poor weight distribution), or we move the kingpin (and then have to move the rear axle - to stay 41' compliant), or I get an 11' upper deck. What do you guys think is the best solution?

 

Do you already have the top corner cut away mudflaps installed?
I'm thinking with them that close, you'll tear what you have off somewhere that it is less than flat.

 

the mudlflaps on my truck - since i bought it - had the outside top corner cut off. this should help, i guess. also, their engineer did a quick projection on the computer and it showed the TURNING RADIUS of the trailer's kingpin (with my fifth wheel in the ideal position) was 78 7/16" or 2 7/16" beyond the mudflaps on the truck. It's more than I though initially, but still pretty tight. darn, i should've gone with an 11' upper deck ...

 

I would almost guarantee you'll destroy your mudflaps within a month. Just think of dips going into shippers/recievers not to mention jobsites.

Are you always going to be @ max gross wt. where weight distribution is critical?

How about moving the 5th. wheel slider back so you can slide back of C/L on light loads?

 

When i was pulling flats for western express, we had to move the 5th wheel all the way back to make the drop decks miss the mud flaps everytime we pulled one, luckily the way our trucks were set up along with the spread axle on those trailers,weight distribution was never a problem even with rather heavy loads. You will probably need to move that fifth wheel back. Like said above, as long as you are not maxed out on weight every single time you should not have many problemsmspread axles are alot easier to get right than sliding tandems.

 

I will have fixed tandems with a 61" spread.

 

what would you say is a safe clearance between the truck's mudflap and the landing gear of a stepdeck trailer? 6 inches? 12? or something else?

 

Why dont you just make a new mudflap hanger setup.
Take a some 2"x2" square tubing .125 wall and mount it as far forward as you can to the drives without interference and then 45 the ends and mount the flaps to that.You would prolly get by with doing this as you would be moving the flaps forward and lowering them due to the fact the bar would be mounted to the bottom of the frame rails.

 

that's a good idea, thanks. i saw a couple of trucks with mudlflaps like that. i might do it later on, but for now after lengthy discussions between the trailer dealer, the plant and myself, we agreed to extend the upper deck by 1 foot and leave everything else the same. This will give me enough clearance and I'll still be able to slide the fifth wheel.

The latest spec is:

48' total length
combo composition: steel frame + aluminum
aluminum floor with 4 nailers
steel coil package
11' upper deck
24" kingpin
45" heght from ground to the upper deck
34" height at the lower deck
tandem axles with 17.5" tires, aluminum rims, 61" fixed spread.
31" from the center of the rear axle to the end of the trailer

From my experience, 10 ft upper deck just doesn't work - the landing gear is too close to the truck.

 

Sounds like you're getting it together Tracer.

The only drawback of the 38' bottom is you can't haul a loaded 40' container because of the 2' overhang.

I used to run L.A. a lot and the guys with a 40' lower deck would get out quicker, usually with a 40' high cube.

Just my $.02.