There used to be a (InstallShield/Flexera Software) AdminStudio SCCM Edition that was free for SCCM customers of Microsoft. That's the closest I can think of as "free".
Truthfully I don't even use AdminStudio or the InstallShield repackager anymore. The authoring quality is just too low for me. I'll use free tools to capture what the installer did, reverse engineer the rest of the details, refactor as needed then write it from scratch using Windows Installer XML (WiX).
It takes a lot of knowledge and experience to be able to do all that, but it's all possible with free tools.