Ok so..Everytime I transform him back into his truck mode of sort is side piece/top panel his never flushed in, what am I doing wrong? I feel as if I'm going to force anything it will add more stress marks than it should.

 

On his legs there are odd little grooves that the thighs lock into, if you don't do that they legs aren't flush and cause that usually.

 

I've found that the best way to get them flush is to line everything up, then stick your finger into the bottom of the vehicle mode and push it outwards a bit. It's a little tricky the first time, but you'll get the hang of it quickly.

 

Yep, it's all about the legs. Push the gray piece on each of the upper legs together with the blue lower pieces. They will click together at what would be his thighs in robot mode and allow you to put the top panel down.

 

Well see that's the thing those pieces are lock in place that's why I'm trying to figure out why it's like this.

Edit - Nevermind you guys are talking about a different part.

 

You have to transform each leg separately before pegging them together.

 

You also need to spin the pipes around so they fit to the legs. Those grey pieces with the grooves.

 

I was just about to say this.

His exhaust pipes rotate and fold down just a bit more to sit flush with his back end, that should help a little. Also make sure you've got the legs slid/retracted/whatever you want to call it all the way