I found this on Wikipedia...first i had heard of the money issues, but sounds a lot like JJ's claims as well...
Bickler left the band in late 1983 after he developed polyps on his vocal cords and required surgery and voice rest, a condition that would take a year and a half to recuperate from. Bickler was also unhappy about his lack of a bigger payday he felt was owed him for the multiplatinum success the band had from their hit album Eye Of The Tiger released a year earlier. After leaving Survivor, Bickler continued recording with other groups in the Chicago area and doing commercial jingles and ads.