While he doesn't provide hyperspeed tempos or manic fills, that's still Steve Shelley on her first two albums.
Matt Sweeney from Zwan plays guitar on "Salty Dog" from The Covers Record, and on Jukebox.
On You Are Free, DaveGrohl plays drums on "Shaking Paper, "He War" and "Speak for Me" (where he also adds bass), Eddie Vedder does additional vocals on "Good Woman" and "Evolution" and Warren Ellis (not that one) plays violin on "Good Woman". And to top it all, the album was engineered and produced by Adam Kasper, a pretty well knownAlternative Rock producer.
The Greatest has guitars by Teenie Hodges and bass by his brother Leroy. You might know them from their work with Al Green. Teenie returned on Jukebox as well.