DIY Chevy Avalanche Bed Slide: Build Your Own Sliding Cargo Platform

Published September 6, 2026 · How we source this

The Avalanche bed is short, closed in by the sail panels, and the factory side boxes eat into the floor on both sides. Anything against the midgate means climbing in after it.

A rolling platform brings the cargo to you instead. Drop the tailgate, pull it out, load standing on the ground, push it back in.

This one is 48″ × 62-3/4″ plywood on 13 casters, framed underneath and carpeted, built from scratch around the bed. The build is on the FullSizeChevy YouTube channel — this is the written reference: dimensions, cut list and caster coordinates.

The finished bed slide

Spec	Detail
Platform size	48″ wide × 62-3/4″ long
Material	Nominal 1″ marine grade plywood
Frame	1×1 treated, perimeter, underside
Top surface	Carpet, wrapped and glued
Casters	13 total, 2″, 90 lb each
Locking casters	2, tailgate end of the outer tracks
Hand openings	2, 2″ × 6″, tailgate end

Two outer tracks of five casters carry the platform, a pair of interior casters picks up the middle of the sheet, and one caster at the cab end sits on the centreline.

Materials and cut list

Download the blueprint (PDF) — platform and frame on page 1, caster layout on page 2.

Plywood

Qty	Size	Material
1	48″ × 62-3/4″	Nominal 1″ marine grade (cut from a 4×8 sheet)

Frame — 1×1 treated, 2 × 10 ft lengths

Qty	Length	Notes
2	48″	Cross members, tailgate and cab ends
2	61-1/4″	Side rails, between the cross members

Cut one 61-1/4″ and one 48″ from each 10 ft length. The 61-1/4″ only works with stock that actually measures 3/4″ — 62-3/4 minus two 3/4″ cross members. If yours is a true 1″, the side rails are 60-3/4″. Measure the stock, don’t trust the label.

Casters

Qty	Type
11	2″, 90 lb, non-locking
2	2″, 90 lb, locking

All 13 the same height, and the wheels have to track fore-and-aft. Free-swivelling casters that let the platform wander sideways aren’t a substitute, even if the rating matches.

Fasteners, adhesive and finishing

Item	Spec
Frame screws	~30, exterior #8/#9 × 1-1/2″
Caster screws	52 (four per caster), exterior #10 × 3/4″, washer or pan head
Construction adhesive	2 tubes, PL 400 or equivalent
Carpet	62″ × 76-3/4″ — 7″ of wrap on every edge
Carpet adhesive	Carpet-rated
Staples	Corrosion resistant
Edge sealer	For the cut plywood edges
Extension stop / restraint	See below
Stored-position restraint	See below

Tools: circular saw, jigsaw for the hand openings, drill/driver, countersink and pilot bits, tape, square, straightedge, clamps, staple gun, and a trowel for the carpet adhesive.

Measure your bed first

The 48″ × 62-3/4″ came off this truck. Bedliners, trim and clearances aren’t identical across every 2002–2013 Avalanche, and marine ply is too expensive to guess with. Get a tape in the bed and write down:

Width at the narrowest point — between the side boxes, not down at the floor. That minus your clearance is your platform width.
Midgate to closed tailgate, including hardware standing proud of the midgate.
Wheelhouse intrusion — where the tubs come in, and at what height.
Bedliner ribs — height and spacing, and whether 2″ wheels ride the tops or drop into the valleys.
Tailgate height against the bed floor — the gate isn’t always level with it, and that step is where a wheel drops or climbs.

If your numbers come in tighter, cut to yours. The caster layout scales off the edges, so a smaller sheet doesn’t break it.

Caster layout

All positions to the centre of the caster. x from the driver edge, y from the tailgate edge.

Position	x (from driver edge)	y (from tailgate edge)
Driver outer track	4-1/2″	2″, 14″, 26″, 38″, 50″
Passenger outer track	43-1/2″	2″, 14″, 26″, 38″, 50″
Interior pair	19-3/8″ and 28-5/8″	26″
Centre, cab end	24″	60-3/4″

Thirteen casters. The two at y = 2″, closest to the tailgate, are the locking ones. Page 2 of the blueprint has it drawn out.

Outer-track spacing is a clean 12″, so once the two 4-1/2″ lines and the centreline are struck the rest is a tape and a chalk line. Note that every caster sits inboard of the perimeter frame — they all screw into plywood, not into the 1×1.

Building it

1. Measure the bed. See above. Every cut below depends on it.

2. Cut and label the plywood. 62-3/4″ off the length of a 4×8, full 48″ width. Mark the tailgate end and the top face — the caster layout isn’t symmetrical end to end and it’s easy to flip the sheet and lose track. Seal the cut edges.

3. Dry-fit the frame. Two at 48″, two at 61-1/4″. Cross members at the ends, side rails between them. Confirm the perimeter closes flush before any glue comes out of the tube.

4. Attach the frame. Adhesive plus 1-1/2″ exterior screws every 8″, predrilled and countersunk — treated 1×1 splits, and a proud head holds the frame off the plywood. Check screw length against your actual plywood thickness. Through 3/4″ frame stock, a 1-1/2″ screw puts 3/4″ into a sheet that may only measure 3/4″. Longer screws come out the top.

5. Cut the hand openings. Optional. Two at 2″ × 6″, 4″ from the tailgate edge, 18″ in from each side. Lay them out and look at them before you drill — those callouts put them tight together at the centreline and you may want them spread wider. Drill the corners, jigsaw, then round and sand the edges. You’ll be pulling on these with gloves.

6. Carpet the top. Trowel the adhesive, lay the 62″ × 76-3/4″ piece, wrap the 7″ of overhang under all four edges and staple it. Weight it down while it cures, and give it the full cure time before flipping or loading.

7. Mark and set the casters. Strike the two 4-1/2″ lines and the centreline, lay out from the table above, verify twice. Predrill every hole. Four 3/4″ screws per caster. Then check each one: roll direction right, all four screws seated and none proud, nothing spinning free, no screw tip near the top face.

Installing it

Level ground, transmission in Park, parking brake set, engine off, and a second set of hands — it’s awkward even empty.

Install it empty. Set it in at the tailgate, align the wheels with whatever they’ll run on, push it in slowly by hand, and watch the bed-to-tailgate transition. Then roll it in and out several times looking for binding, a wheel climbing or dropping, sideways walk, contact with the side boxes or wheelhouses, tailgate interference, or flex through the middle. Fix what you find before it carries anything, then add cargo gradually.

Two things it needs before it hauls anything:

A positive extension stop or tether — something mechanical that stops it rolling past its travel and off the back.
A separate stored-position restraint — so it can’t launch forward under braking or roll out when you drop the gate.

Caster brakes are not a restraint. They keep it from drifting while you load. They are not what keeps it in the truck.

Load rating and safety

The casters are rated 90 lb each by the manufacturer. Thirteen of them is where the blueprint’s 1,170 lb comes from.

That number assumes the load sits evenly across all thirteen wheels, which is the one condition a truck bed never gives you. Cargo concentrates — put a few hundred pounds over one corner and the casters under it are past 90 lb each long before the total is anywhere near 1,170. It also rates wheels and nothing else: not the plywood, the frame, the screws, the mounting, the bed or the tailgate. Every caster is screwed into plywood, not into the frame, and the finished assembly has not been load tested.

Spread your load out, stay well under the number, and don’t treat it as a target.

Never stand, sit, kneel or climb on the extended platform. It’s a cargo platform, not a work platform and not a step.

Level ground, truck in Park, parking brake on. Hands and feet clear of the pinch points. Keep control of it — never let it free-roll. Restrain it extended and stowed, secure it before driving, and strap your cargo down independently.

Watch the build

Final thoughts

A rolling platform doesn’t add space to the bed. It makes the space that’s already there reachable without climbing in after it, and for a sheet of plywood and a box of casters that’s a fair trade.

Measure your own truck first. That’s the part that decides whether it works.