Flatbed rear wheel articulation

[craiglathem]

Hi, just placed an order for a flatbed Hawk to be installed on a 2019 diesel F350. I notice that in pictures of some of the flatbed installs there doesnt seem to be much room for rear wheel articulation. It could be camera angle but on some the tires look pretty snug in there. Has anybody had an issue with this? I am thinking I would run 35 inch tires with a 3 inch lift.

 

[Wango]

Craig,
I would think it depends on the type of bed and installation.
I run 35s on my 2016. leveled front, and rear suspension was modified to keep level, but no real lift.
Is this going to be a cab and chasis bed, or will you take of the regular bed and then put a flatbed on.
My bed is about 5 inches higher than the stock bed was.
w

 

[klahanie]

I had a deck put on our F350 chassis cab. I consulted the site below to find the spec for rear tire jounce - upward travel ON EDIT in this case from an unladen state. Loading can reduce remaining travel. For eg a 2018 CCSB PU 4x4 with 10K GVWR it lists 5.6" + 0.5" for clearance. (see doc pg 26)

https://madocumentupload.marketingassociates.com/api/Document/GetFile?v1=4311733&v2=060118102504&v3=60&v4=45dbbe577f9d338234fc31eecf98ec222b8c1946a09647cffb88778c&v5=False

Our deck was put on with the stock tires still mounted and I had plans for oversized plus be able to run chains so I added 1.5" to the oem clearance number. Of course many owners mod the rear suspension, that changes things and can be tough to calculate for.

Our much stiffer leaf spring main pack and overloads greatly reduce the chance of ever being at full jounce. Still, you might be surprise at how all that camper and gear weight can stuff a single rear tire in an off camber situation.

The first number for our model was 6.7", IIRC and we ended up with 6" between the tire top and deck bottom. That's loaded for a trip, all good. With 3 yds of soil in the bed it is less

As for looks, on ours the space above the rear tire does look a bit tight, especially compared to the fronts. Bear in mind some deck designs have some form of flare, edge or skirting around, or just at the top, of the wheel space (good for debris control). This can make the space appear smaller but can still work okay if the tire travel fits inside of it (may need a little wider deck to ensure this).

It's good to think about and discuss these things with your upfitter ahead of time, so no surprises.

 

[rando]

I had this concern when installing my flatbed, and ended up with too much wheel well clearance! I measured the current distance between the top of the wheel and the wheel well on the stock bed, then mounted my flatbed to maintain that clearance. However, my suspension upgrades ended up with 1-2" of unwanted lift, meaning I had more clearance than stock. I have flexed the truck more than I probably should have over the past couple of years and have never rubbed a tire. If I ever unmount the camper, I would take that opportunity to drop the flatbed height by 2" or so for better handling and stability.

As a first cut - measure the current wheel to wheel well clearance, then subtract what ever lift you expect (and add tire radius increase) and start with that.

 

[craiglathem]

Thanks for the feedback. Yes, I should have mentioned, I will be getting a Norweld flatbed and likely run 315/70/18 Toyo Open Country which is about a 35 inch tire. I had thought I would run a 2.5 inch lift to accommodate the tires but still not sure about that.

 

[Ace!]

I'm sure you won't have a problem. I bought a 2016 F350 and installed a flat bed and ran 34" tires with no lift and tried to rub the bed and couldn't.

 

[klahanie]

Installed lowest possible is prob best. Ideal world you could adjust after.

I had a 1" frame spacer used as the "interface" between chassis and deck unfortunately the concept wasn't carried thru to the mount. If I could do it easily I'd lower all by that 1".

Real world you'll prob get what you're given.

Many owners dislike any sag. Once they see loaded up compared to "factory height" they jack the rear. Best to see how it handles first anyway. Prob won't bottom out the rear on a F350 but might the front so both ends could get reworked, benefiting tire to deck clearance as well.

 

[Durango1]

On my 2018 Ram Chassis cab we're running the off-road 32"(?) factory tire and have a (heavily) loaded bed/tire gap of 4 1/2". So far we've never rubbed but I'll probably wind up placing air bags just to raise it a bit and (I hate to say) improve the appearance! (I've removed the back underbed boxes. Trying to cut the behind-the-rear-wheels weight.)