Commuters heading to Sydney’s south-west have been hit with two-hour delays after a garbage truck fire closed all westbound lanes of the M5 motorway during peak hour.

The drama unfolded just before 4pm on Friday when a garbage truck loaded with paper and cardboard ignited while travelling on the M5 at Milperra.

WATCH THE VIDEO ABOVE: Truck fire causes M5 peak hour chaos

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The driver attempted to dump the load but it was too late, with flames taking hold of the front of the rubbish truck and destroying the cabin.

Fortunately, no injuries were reported, but the damage for commuters had already been done.

All westbound lanes on the M5 were closed as firefighters battled the blaze, with traffic backing up 10 kilometres.

A garbage truck caught alight. Credit: 7NEWS

Traffic queued for 10kms. Credit: 7NEWS

Traffic remains backed up into the evening. Credit: 7NEWS

Aerial footage from the 7NEWS helicopter showed the motorway transformed into a car park, with frustrated commuters getting out of their vehicles as they waited in bumper-to-bumper traffic.

Authorities have since allowed the backed-up traffic to clear and it is moving through, but the M5 westbound remains shut while the site is cleared.

Diversions are in place, but motorists are being urged to avoid the area entirely if possible.