42108 Roll-off Truck

An alternate model for 42108 Mobile Crane:

Inspired by DAF CF trucks:

But first, what is a roll-off?

Roll-off truck at first glance looks like a hook loader or dump truck. The difference is how the whole loading/unloading of container works: the roll-off truck raises its hydraulically operated bed, the roll-off container rolls off the bed. A cable is used to slowly lower the container. After the waste container is loaded, the roll-off truck pulls the filled container onto the roll-off truck with the cable and winch system.

Comes with three manual functions, which are HoG steering, bed elevation and winch.

Model usues almost all parts from the set, which allowed to make detailed interior and exterior, with working steering wheel, openable doors, dashboard, air filter on the roof etc:

Let’s start with the container:

It almost does not have any gaps, so it can hold almost anything, starting from 1×1 plates, up to large chunks of “scrap” (here made from remaining parts):

Rear door of the container can be locked:

Underside of the container have added self-guiding rails, making loading of the container easier, if it’s not perfeclty aligned. Presented here by Rudolf:

This model can work as a regular dump truck:

Or as a roll-off system truck:

Both functions are operated by knobs located on either sides of the frame. Basically, whole middle section of the chassis is built around the XL actuator.

Here’s the video showing how it works:

Model comes with instructions, here are few sample pages:

Before you buy these instructions, please read the following really carefully.

– Please make sure that all axles and gears spin freely, it is crucial especially on the winch side and release rachet side

– model does use spare parts, some people just forget about that 😉

– at page 4 don’t miss two 4274 Technic Pins 1/2 placed on the steering arms, they limit steering angle of the axles and allow to run all wheels smoothly

– the rope must be placed correctly on the winch, the release ratchet will not
 work properly if rope will be wind on wrong side. The rope must be tied between two of the o-holes in the pulley wheel with knot placed to middle of the winch, using technique from 42108 A model will jam the winch, because knot will stick outside the pulley wheel and rub on the 5×7 frame.

– At page 96 the Red 8 axle has to be placed with half stud displacement in the frame.

Instructions can be bought at Sellfy:

And Rebrickable:


Few comparison shots with test model (yellow door on the container looks better, don’t you think?)

And with my MAN TGS:

This model could be also built (after few colour swaps) in Red:

More pictures can be found here:


About the author

A 30 year old LEGO fan, who sometimes build something.