Abstract: A trailer is provided with a bed and a slidably adjustable axle assembly. The bed includes a frame with left and right, inverted U-shaped channels. The axle assembly includes left and right rails upon which the channels are slidably mounted. Pins extend through the channels, but not through the rails, to limit sliding movement of the bed relative to the axle assembly. The pins are inserted into the channels with a twist lock action under spring bias. Lock members are provided to prevent accidental removal of a pin from the channel during travel.