This is how Exposing Makeshift goes in Con Job.
[Starlight and the others arrive]
Starlight Glimmer: Bulkhead, he's lying! Wheeljack isn't who you think he is! He's a Decepticon shifter in disguise!
[But Bulkhead is not listening]
Bulkhead: Look, I know Wheeljack better than anyone.
[Applejack and 'Wheeljack' come in]
'Wheeljack': Hey. What are you guys talking about?
Bulkhead: I was just telling the guys all about you and me at the Battle of Darkmount Pass.
'Wheeljack': That's a heck of a story.
Bulkhead: Yep. Tell it.
Applejack: Talk, talk, talk. How about after we go check out the corridor?
Bulkhead: Applejack! Stay out of this!
Arcee: Bulkhead, easy.
Rainbow Dash: Yeah calm down.
'Wheeljack': I'm not sure I --
Bulkhead: Tell it!
'Wheeljack': Fine. You wanna live in the past, Bulkhead? The Wreckers were trapped between a Decepticon patrol and the smelting pit. The Cons were vicious, bearing down on us with everything they had. Me and Bulkhead engaged the enemy, left them for scrap, then I made us a way out using their backsides as stepping-stones to cross the molten metal. Isn't that how it happened?
Bulkhead: Yeah. That's exactly how it happened. Except for one little thing.
[Makeshift's eyes widen]
Bulkhead: I wasn't there.
[Ratchet stops working on the Groundbridge and looks up]
Starlight Glimmer: You're busted, Con!
Trixie Lulamoon: That's right!
Thorax: We've finally caught you!
Discord: You don't need to hide you really are any more!
Bulkhead: I'd already left the Wreckers to join up with Optimus. But you would know that if all you did was access Wheeljack's public-service record.
Applejack: Bulkhead, what does that have to do with this?
[Makeshift grabs Applejack and runs to the Groundbridge]
Makeshift: Stay back or I'll squish her like a bug!
[Everyone watches in horror as Makeshift changes into his own form]
Applejack: What in tarnation...?!
Bulkhead: Decepticon coward, let the Earth Pony go and face me!
Makeshift: Why should I? Would the real Wheeljack act like a coward?
Starlight Glimmer: Is there a real Wheeljack?
Trixie Lulamoon: If there is...
Thorax: We just need to find him.
Discord: That's right.
Makeshift: Oh indeed and I expect Lord Starscream is making sport of him. [looks at Starlight, Trixie, Thorax, and Discord] And it seems it didn't take these four long enough to figure out I'm not Wheeljack.
[Starlight is shocked]
Makeshift: Ha ha ha. It's funny, really. Starlight, Trixie, Thorax, and Discord here knew I was a Decepticon ever since they saw me contacting Lord Starscream. Too bad the rest of you were to caught up with your partying to figure it out.
[Meanwhile, on the Nemesis, Starscream and Soundwave are waiting]
Starscream: Are you certain we are at Makeshift's location?
Starscream: Then what is taking him?!
Wheeljack: Maybe they gave your friend the old friendship blast.
[They turn to see Wheeljack free of his binds]
Wheeljack: He got the warm fuzzies and decided to switch sides.