Bolt-together frame kit guide for
Compact Camping Concepts Explorer Box Camping Trailer
Revision 2.02 04/25/15
Bolt-together frame kits are a budget friendly option for building an Explorer Box trailer on.
There are many sources for bolt-together frame kits, Harbor Freight is the most readily
available and recognized name.
This guide is based on Harbor Freight’s, Haul-Master #94564 1720 lb. capacity super duty 4’ x
8’ utility trailer with 12" five lug wheels and tires.
A standard Explorer Box is based on a 4’ x 6’ frame, so a few modifications are necessary.
First, the length of the frame deck gets shortened from 96” to 72” long. Second, the position
of the spring hangers gets relocated so the axle center line is 27” from the rear of the frame.
To make these modifications, you will need a drill, 7/16” drill bit, a couple of clamps and a
way to cut steel. For the steel cutting, a hacksaw works, although a 4 1/2" angle grinder with
a cutoff wheel goes much faster.
Start by reading the Harbor Freight Haul-Master #94564 frame kit manual and understanding
the “standard” frame building process. This guide follows and references the manual steps.
Build the frame:
Per the Phase 1 assembly instructions, build up the front 4’ x4’ section.
Per the Phase 2 assembly instructions, build up the tongue section.
Copyright 2007-2015, Compact Camping Concepts LLC
Phase 3 requires modifications, the side rails will be shortened and rear 2B cross member will
not be used. Side rails 1RL &1RR get shortened to 24”. The cut goes through the bolt hole
where the center 2B cross member would normally be bolted. The shortened side rails need
new 7/16” dia. holes drill for attaching the center 2B cross member which now becomes the
rear one. Then assemble the shortened side rails with a front and rear cross member per the
instructions.
Copyright 2007-2015, Compact Camping Concepts LLC
Per Phase 4 instructions, bolt the front and rear sections together.
Phase 5 requires modifications, the spring hangers get positioned in a new location and needs
new holes drill. The front of the spring hanger (end with holes on top & side) gets positioned
31 1/4" from the front of the frame. This puts the axle centerline 27” from the rear of the
frame.
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Here is the spring hanger holes location information. Three new 7/16” diameter holes need
to be drilled in each spring hanger. The new holes are “C”, “D” and “E”. Hole “C” is
positioned over the rear section, front corner cross member hole. Holes “D” and “E” are
position in approximately the same location as “A” and “B” on the front end of the bracket.
“F” is the square hole on top of the spring hanger.
With the spring hanger clamped in place, drill the six (per side) new 7/16” diameter hole
through the frame. “F” is drill through the square hole on top of the spring hanger. Now
referencing Figure E in Phase 5, bolt the spring hangers in place. For “A”, “B”, “D”, “E” and
“F” use part #B M10 x 25 bolts. For “C” use part #C M10 x 30 bolts.
Per the Phase 6 assembly instructions, attach the springs and axle, but do not attach the
fender seats or fenders.
Per the Phase 7 assembly instructions, install the hubs and tires. DO NOT overlook step 1,
cleaning and packing the wheel bearings.
Per the Phase 8 assembly instructions, attach the couple and safety chain, but do not attach
the side marker or tail lights at this time.
Phase 9, depending on where your taillights will be installed, you may defer this until after
building and attaching your trailer box.
Copyright 2007-2015, Compact Camping Concepts LLC
Your Basic Frame is now complete! Be sure to read and follow the operating instructions and
safety portion of your frame manual.
An additional item I put on all trailers is a swivel tongue jack. These make moving your
trailer around much easier and allow you to level it.
Copyright 2007-2015, Compact Camping Concepts LLC
Another additional item if your Explorer Box will be Tent Topped, is a pair of rear leveling /
stabilizer jacks. Bolting them to the rear cross member is an easy way to install them. Too
better protect them, make brackets and angle them in.
Copyright 2007-2015, Compact Camping Concepts LLC