3rd Gen 4r rear brake shudder

So my friend and I replaced the rear drums, shoes, and springs today and one the drive home (after doing a test drive to break the shoes in) a really bad shudder started happening. The harder I push the pedal, the harder the shudder. I don't necessarily feel it in the pedal, but I can feel the whole truck move at any speed. My friends dad said it could be that the shoes are on backwards, but each shoe had its own pin for something and it all lined up the way it had before we replaced anything and it does it in reverse too, so Im not sure thats the case. I don't think the drums are misshapen because as I said earlier, theyre brand new. A similar thing happened about 10 years ago and the way we fixed it was by getting new brakes, so thats kind of a dead end. Any adive on where to start?

 

Are you sure you bedded the shoes in correctly? There's a whole procedure that needs to be followed after changing the shoes and/or pads. A certain number of brake applications at a certain speed and pedal pressure, then a certain number at another speed and pedal pressure, and so forth. The procedures are readily available on google, and so forth.

Also, are you sure all the air was bled out of the system before you started driving? Air in the system, including the LSPV if there is one in the system, will cause this trouble.

Finally, are you sure the ABS system is properly aligned? The FSM has a complete how-to on that.

I recently had my rear shoes, AND front pads replaced, by, of all places, a dealership, with no trouble at all. Yeah, I was amazed too! I had to do the bedding myself on the way home, but didn't have any trouble doing it. I read up on it in advance, so it was an easy procedure to remember and follow. Even just from memory, and my memory aint all it once were.
The brakes were bled out before I got the truck back, so that wasn't any concern. Same with the ABS, so that was taken care of...

Hope that's some kind of help...
Pat☺