4R55E Shift Kit Upgrade
Is anyone using or herd of anyone using a SONNAX shif kit for a 4R55E.
At 60,000 miles I took my truck in for a trans service, they put a Transgo shift kit in my 4R55E. I felt a little difference but not much. Well now at 101,650 miles the trans is giving me more problems even after a full service.. (every 15K).... I found a company "SONNAX" that sells a better looking kit that comes with redesigned control valves and springs. Iam trying to see if anyone know any thing about that company befor I buy...