rear bumper build Qs

[point45]

Finally got the latch system mounted.

it took a little more modifying than i was planning on, and of course during a buzzed brainstorming moment, i cut the swingout too short. I had to mill up a scab piece to make it work. im gonna plate the bottom of the splice for good measure. Fortunately you cant see my screw up.

 

[rebelgregory]

Lookin good.

 

[Blue85]

Looks like a good original design. Don't underestimate the leverage the tire will exert on the carrier and bumper. I recommend a solid clamp on the latch end and not just something that keeps it from swinging (I can't really see what you have). You have to minimize the ability to shake/vibrate at both ends of the swing out. Once you have a heavy wheel/tire on the end of a stick it wants to bounce and shake until the welds crack. You may also need to brace the hinge side of the bumper to a point further forward on the bumper to prevent "twist" at that end.

I had a trailer spindle initially and it eventually cracked and broke off. I moved to a 10-bolt front hub which is more rigid but that end of the bumper still wants to twist as the tire tries to bounce forward/back. I braced that end to the frame with 2" tube at about a 45-degree angle which helps, but it still shakes a little. It is actually cracking welds in the front of the bumper now (that end is fully boxed on mine) which I need to repair.

 

[point45]

Blue,
i hear what your saying, mounted the tire today. im kind of baffled with the amount of flex that in the bumper, just watching it rack when the door is open as I pushed up and down on it, i even saw my frame moving. I am definitely going to have to brace it some more and reinforce the hinge, to take the play out of it. I was worried driving home it was so bouncy when i would shake it, but i was surprised it didn't rattle or shake even on the freeway.

As for the latch, I think its pretty solid. i planed on putting some rubber of plastic bumpers underneath the swing arm to hopefully bind it into a downward position. to delete the vibration. I am considering having a T-handle to take out the play, but i dont want to corss that bridge yet.

the tire is parallel to the rear of the truck, the angle of the picture sucks

 

[Blue85]

Well look at the hinge side of the bumper. It's just two pieces of plate and one steeply angled brace. You should enclose that end of the bumper entirely, preferably all the way back near the frame rail. Then move the brace further forward to some existing hole in the frame ahead of the spring hanger. This isn't about making it strong enough to hold a tire. You're way past that already. It's about rigidity which is a lot more challenging - because trucks move. Focus on the best you can do to add rigidity in the space available instead of the static situation of the truck parked in a driveway. You will inevitably hit the resonant frequency of the bumper/carrier system while driving, so rigidity is required to bring the resonant frequency as low as possible (i.e. stiff as possible). Without a tire everything would be peachy, but with 100+ lbs up on an arm...

 

[point45]

you have some really good advice, i appreciate it.

i stiffened up the hinge side today, ill probably relocate the hinge brace tomorrow and work on boxing it out. I think im also going to take it off and add a cross member between the frame rails.

 

[evolve991]

Some wicked sweet bumpers in this thread. Almost shames me on my plan to wrap a 5"x10"x5' lambeam in workable diamond plate

 

[point45]

almost done. still need to add the water can. I dont have pics but i ended up boxing out the ends and bracing it back to the frame. the bumper is strong as hell, but i think i need to stiffen the swing arm some more, it shake more than i would like. But deer season is here, so i dont see much more being done until that is over.