In a filling submitted to a California State court, Gross accuses "a cabal" of Pimco bosses of "plot[ting] to drive [him] out of Pimco in order to take, without compensation, [his] percentage ownership in the profitability of Pimco".
"Their improper, dishonest and unethical behaviour must now be exposed."
Gross sensationally left the company in September last year, moving to rival fund manager Janus Capital.
At the time, he said he looked forward to "returning my full focus to the fixed income markets and and investing, giving up many of the complexities that go with managing a large, complicated organisation".
His departure came just months after his former heir apparent, Mohamed El-Erian, stepped down, citing a desire to spend more time with his family - although there had been reports of in-fighting between the two.