40 ILCS 5/8-239
The fund herein provided for shall, on July 1, 1923, and thereafter, supersede and take the place of and have transferred to it the assets of any municipal pension fund which is in operation in the city on June 30, 1923, under the Public School Employees' Pension Act of 1903, and the fund herein provided for shall be a continuation of such municipal pension fund.
All annuities, pensions, or other benefits allowed prior to July 1, 1923, by the Board of Trustees of such Municipal Pension Fund and all claims pending or ungranted on July 1, 1923, which thereafter are allowed according to the law establishing such municipal pension fund by the board herein provided for, shall be paid by the board from the fund herein provided for, according to the law or laws under which such annuities, pensions, or other benefits were allowed.
40 ILCS 5/8-239