I bought an RTIC 65 ice chest for camping and it works great, but it is way too heavy when loaded up with ice and stuff. I started just leaving it in the bed of the truck. That doesn't help when headed over to the r lpiver edge.

So, looked around and commercial wheel kits were way too expensive. (I got a 50% off deal on the chest, so I'm not gonna spend that same amount for wheels.)

I wanted the wheels to roll on many surfaces, be easy to remove, and compact. I also wanted to be able to store the wheels INSIDE the cooler when not in use. (Of course, I'll put them in a large trash bag before putting in the cooler.)

I bought the wheels at Harbor Freight (20% off, each) and all other stuff at Home Depot. I use a lot of metric size hardware because it seemed to fit the holes in the chest a little better than equivalent 3/8" parts.

Here's what I came up with. (Sorry about not getting all the pics... most were taken after the first set of wheels was built.)

Additional items:
1) I haven't needed to do this, but if you want to connect the axle platforms together, you could probably just run flat steel bar from one to the other, connecting with a similar t-nut installation on each platform.

2) Need it to turn without lifting? Maybe replace the axle on one platform with appropriately sized casters.

3) Got a Yeti or different cooler? Just make appropriate changes to measurements. Although I think Yeti only has a single hole at each corner rather than two like the RTIC does.

Supplies

(4) Pneumatic tires with 5/8" hub
(2) wood board, 15 1/2" x 3 1/2" x 3/4" (hardwood such a poplar)
(2) 5/8" x 20 1/2" steel bar
(8) M10-1.50 x 45mm cap screw
(8) M10-1.5 nylon lock nut
(16) M10-1.5 hex nut
(8) M10 washer
(8) M10-1.5 T-nut
(4) 1/8" x 2" cotter pin
(4) 1/8" lock pin
(8) 5/8 washer
(4) 1/2" EMC two-hole strap
(8) wood screws, hex head
Primer and paint

Step 1: Prepare Axle Platform

I'm making the axle platform from wood because I don't have a welder and welding services around here want a ridiculous price for making just the 6 welds per platform I'd need.

The picture for this step is a completed axle platform and measurements for the four peg holes. (Ignore the bolts already in the board; I forgot to take pictures as it was being built.)

So, here's the axle platform instructions. Note that you can work on the axles while waiting for primer/paint to dry in the last few steps.

A) Cut two 15 1/2" x 3 1/2" x 3/4" planks from poplar or other hardwood.

B) Round two adjacent corners along the long edge of the plank. You might want to stack the would together as you cut/sand the edges so that both planks are equal.

C) Drill four holes per drawing specs. Measurements for both sides of the plank are the same. Pay attention to the orientation of the holes and the rounded edge of the plank; the holes closer to the outer edge are closer to the rounded corners.

D) Sand smooth all sides and edges.

E) Apply two coats of primer.

F) Apply two or more coats of outdoor paint. Allow paint to cure before working with hardware.

Step 2: Axles

I'm using 5/8" steel bar for the axles. The 5/8" size fits the hubs of my wheels. If your hubs are different size, you'll need to use a different bar and maybe different two-hole straps as well. Also note that my wheels have a 1 1/2" hub width. If your wheel hubs are wider, make appropriate adjustments to the axle length.

A) Cut two 20 1/2" sections of 5/8" steel bar.

B) Drill 1/8" hole through center of bar at 2" and 1/4" in from each end of the bar. (Two holes each end.)

C) File smooth each end and remove burrs from holes (if any).

D) Paint axles with black metal paint. (Be sure to clean the bar with acetone to remove any yucky stuff to ensure paint will stick.)

E) Allow paint to cure before continuing.

Step 3: Fit Stubs Onto Axle Platform

Since I'm not welding rods to metal as I would have preferred, I needed some way to get stubs to attach to the board. The stubs fit into the rubber holes in the bottom of the ice chest and keep the wheel plank/axles in place.

I chose to use metric M10 size screws and nuts because they seem to provide a better fit into the rubber holes under the chest. You could substitute 3/8" screws and nuts, but I'm not sure if over time those will wear on the rubber.

We're working on one platform at a time. After completing one, repeat for the second platform.

A) Place one M10 washer on each of the four M10-1.50 cap screws for the platform.

B) Insert the cap screw and washer through a hole and thread a M10-1.50 T-nut onto the other side. Make sure the T-nut "teeth" are pointing towards the wood. DO NOT TIGHTEN. Screw in until just before teeth touch the wood.

C) Repeat for other three cap screws and holes on this plank.

D) Hand-thread a M10-1.50 nylon lock nut onto the end of each cap screw, making sure the rounded part of the nut faces away from the wood. Screw only far enough to see the tip of the screw flush with the nylon in the lock nut.

E) Place the axle platform, lock nut first, into the holes on the bottom of the chest. Ensure the rounded edge of the platform faces the outside edge of the chest. You might have to wiggle and push each screw into place. Do not push so much that the t-nut starts biting into the wood.

F) Slowly tighten each cap screw, pulling the T-nut's teeth into the wood, ensuring an even tightening pattern. For example, turn one screw one turn, then do another screw, then another, and finally the last one. Repeat. This is done to help ensure the posts are aligned for YOUR chest. Do not fully tighten, but just enough so that the teeth are fully into the wood.

G) Repeat the process for the other platform on the other side of the chest.

H) Remove both platforms from the chest.

Step 4: Complete Axle Platforms

The paint on your axles should be cured before completing this step.

A) Remove the lock nut from each cap screw.

B) Tighten each cap screw to ensure t-nut is fully pulled into the wood.

C) Tighten cap screw heads to align the edges forming a parallel channel that the axle will rest between. See pic.

D) Tighten two M10-1.50 hex nuts to each cap screw. Tighten to ensure they won't come loose.

E) Attach and tighten a nylon lock nut to each cap screw.

F) Place platform onto work bench, resting on the four lock nuts.

G) Lay the axle between the cap screw heads gap, leaving 2 1/2" of axle hanging over each end of the platform. If the axle doesn't lay flat on the board, ensure your cap screw head edges are parallel and make a channel. (See pic.) You may need to grind a notch into the axle in order to get it to rest flat on the board.

H) Gently squeeze the two-hole straps so that they'll provide a tight fit over the axles.

I) Place a two-hole strap onto the axle, just inside the cap screw heads and mark the two holes for each.

J) Drill 1/16" pilot hole for each strap hole. Then secure the strap with two wood screws each.

K) Insert a 1/8" x 2" cotter pin through each inner axle hole and bend the protruding ends to form a loop. (Refer to picture.)

L) Slide a 5/8" washer onto one end, slide on a wheel, followed by another washer, and then insert the lock pin into the outer hole.

M) Repeat step L for all other axle ends.

Step 5: Attach and Test

You should now have two complete axle platforms. Lets insert and test them.

A) Turn the chest upside down.

B) Insert one platform into the rubber holes, lick nuts first, and slowly push until seated. Make sure the platform rounded edge is facing out.

C) Repeat for the other side.

D) Pick up the chest and place down on the wheels. Pull, push, roll it around. The wheel platforms should not be loose and should stay attached even when you lift the chest.

If you've done everything right and the platforms don't fit, you might have to realign the posts. This involves removing the lock nuts, hex nuts, and backing out the t-nuts.