http://www.tfw2005.com/boards/trans...k-rodimus.html?highlight=black+rodimus+convoy

What I did to mine is I took a Dremmel and opened up the pivot hole of the knee cap. This allows for the knee to "bounce" a little more when the leg is rotated while posing.

Ok, so pictures are worth a thousand words:

(Thanks to TFW2005.COM member PoweredConvoy for the original photo help here!)​

Basically, if you're able to get a new knee joint or repair the broken one, insert a Dremel in the pink highlighted area and make that hole just a little bigger. The problem is when the knee joint is turned on the hinge, it's just way to tight and the ratchet joint has no give to it. Opening up that area gives it that room to "bounce" while the knee is ratcheted.

You can also utilize SydneyY's fix found in that feedback thread as well.

I hope that helps!

The only ways I know of to get replacement knee joints are:

• If you bought your figure from a dealer (such as BBTS or TFSource), you can contact them to see if they have replacement parts.
• Buy a second figure, use the knees, and sell the rest for scrap to recoup some losses.

What I've shared can be a preventative measure if someone buys their figure, and doesn't touch it until this modification can be done. Beware that one can still buy the figure like I did, open it up, and have the issue right out of the box.

 

Ok I think the breaks may be caused by some point on the interior of the knee joint.
I posted a video of mine.. I even got brave and tried the knee that I didn't think would stick, and it moved without breaking.

Good luck anyone ordering a clearance one.

T2RX6 Discusses: The problem with MP-09B Evil Rodimus' Knees - YouTube

https://www.youtube.com/watch?v=Zafx8hqzh2s&feature=youtu.be

It was the first time I've transformed him.. Not a case of ratchets wearing out.. I have had a v1, and i've got a v2 and hasbro rodimus, and have transformed them all many times with no problems..

Nothing like this:

 

My poor black Roddy had to have a knee surgery. His left upper knee ratchet joint cracked then snapped off, resulting in the leg falling off - I think that's where everyone is talking about?
I stuck a washer to the broken joint. I can't do any fancy modding so this is the best I can. He is fine so far.


Crossing fingers for no more breakage.


But he's damn gorgeous, and I enjoyed transforming him into the car. I can't align the front and the tires don't roll though  

It's simple really, and I don't think you guys consider it as a proper fix, but here it is.

My Rodimus' knee ratchet joint (upper left one) broke off inside the knee and the lower leg fell off. I opened the thigh and took out the broken piece off, and superglued a washer to the joint.





Other side is a bit dirty because I initially stuck another washer there to make it hopefully more durable, but the joint became too thick to fit inside the thigh and I had to take it off. It is still thicker than it originally was, of course, so there is a gap in the thigh, which can be seen in the pic I posted before.



The knee is still articulated I think because of the added thickness to the joint. The ratchet itself doesn't really work as I can't hear the clicks. And the knee it doesn't stretch all the way anymore. I hope the pic shows what I mean -


But more importantly for me, the knee still bends back and Rodimus is transformable  
In case anyone wants to try the same the washer I used is 8mm in diameter with a 4mm hole. The washer's diameter needs to be smaller than the ratchet joint to allow the movement. It needs to be very thin, too. Hope this helps.

edit 2 I was posing him today and the broken ratchet joint is still clicking. I guess it might be depending on the angle - if the remaining ratchet bits are used, they still function.