Carrie thinks she'd make just as good a boss as Bozer and when he gives her the chance she's determined to prove it.
The machines must clear an old dumpsite to make way for a new car park in just one day. Bozer gives the machines a new batch of fuel as a treat but because Carrie is an electric machine she worries because she is different.
When Diggs starts treating everyday jobs on the construction site as a competition, Bozer decides to introduce a real contest - the Machine Challenge!
It's Maxine's 'mileage day'. Bozer enlists the help of the other machines to organize a Carnival Party to celebrate but it has to be a surprise because Maxine doesn't usually celebrate her Mileage Day and she doesn't like being made a fuss of.
When Scooch spills some salt grit, Diggs fills his head with the notion that it is 'unlucky', so when Bozer tells them they are working on top of a very high building, Scooch is terrified. There is a camera feed from the top of the building to a TV below so Bozer asks Carl and Lug to keep an eye on the little machines. And they certainly make for some great viewing as Scooch's worst fears are realized when the lift malfunctions setting him up for a very bumpy ride!
Lug finds it easy to scoff when he sees the newer machines playing at being Big Rig - the superhero truck - everybody knows there is no such thing as "extra vroom". But when Bozer sends him to an unexplored dumpsite and he begins to sink into the unstable ground he soon finds out that there may be just a little bit of Big Rig in all of us.
When Bozer tells Diggs he's full of good ideas he shares them with Scooch and Carrie. But it seems that Carrie's got a few good ideas of her own and they're soon in disagreement.
Diggs and Scooch are working on foundations and are tired and fed up. When Maxine and Lug reminisce about their younger days when they would 'bodge' a job to get it done more quickly, Diggs believes he's on to a winner
Diggs has a shiny new attachment and is very proud of it. That is until Bozer tells him it's needed on an important new job and Diggs realizes that he doesn't know what it does!
Diggs pleads with Bozer to let him wear some new, really fashionable treads. After tearing down an old warehouse, Bozer asks Diggs to check inside the old water cooler before Carl demolishes it.
The new machines have a lot of bricks to move, that Diggs thinks they could use a little help from Maxine. Trouble is, when Maxine gets excited she starts to mix. And what do you get if you mix bricks? Broken stones!
When Diggs, Carrie and Scooch dig a trench in the wrong place they've struck oil. Diggs and Carrie instantly abandon their duties and plan their new life as famous oil barons.
When the younger machines accidentally knock a load of oil drums in the dock they are too scared to own up to their mistake. They take Carl's hook to try retrieving them but things just get worse as the hook falls into the water.
The machines are laying out the site for a new park. When Diggs and Scooch see the plans they figure they can save Bozer some time and just get on with it themselves.
When there's cement mix to be moved and Carrie's feeling fired up, nothing can stop her - nothing except a flat battery that is!
Carrie and Diggs are scouting for rivets for their collections when Bozer tells everyone that today's job is to clear out an old dock. While in the dock, Carrie spots a trunk full of rivets and greedily tries to pick the whole lot up with her forks.
Carl is preoccupied because he is missing the site where he was made. When he almost drops a sewer pipe on Diggs, the other machines decide to try and cheer him up.
Diggs is jealous when Scooch chooses to work with Carrie instead of him. In an attempt to win back his friend's allegiance, Diggs performs his best Carrie voice while silhouetted behind some tarpaulin.
When Diggs saves Carl from a nasty accident, the older machines decide it's time he started hanging out with them. Even the chance to play with Carrie and Scooch can't distract Diggs from his proud new position!
One day as the younger machines play by the docks, Carl and Lug reflect on their own carefree youth. Lug decides that he's not ready for old age just yet.
Everybody's reversing warning is clear and impressive - everyone's except Scooch that is. When his voice is too quiet to stop Lug reversing into a hold he thinks that the older truck will never forgive him.
It's getting dark. Bozer asks Scooch to take some rubble to the junkyard and Carrie and Diggs decide to go along too. Diggs frightens the other two with made up tales of 'Truckzilla'.
Diggs, Carrie and Scooch are tired of the old machines always telling them what to do. So when Bozer gives them a whole job to complete all on their own, at first they're sure they can see it through.
Bozer tells the machines that its 'out with the old and in with the new' as they are about to construct their first Prefabricated building.
Scooch would like to find something he can do that Diggs can't. But when he tries to max out his maximum load all he ends up with is a flat tire.
The machines are demolishing a beacon on the end of the jetty. Diggs discovers Bozer is scared of water, much to Bozer's embarrassment. In an effort to help him conquer his fear, Diggs reverses along the jetty, encouraging Bozer to follow him.