1970 Mustang Mach I with an original FMX transmission... Problem is whenever I put the car into reverse the car goes forward. What would cause this? By the way the car goes forward in 1, 2, and Drive. Help!
This sounds like a shifter problem or a valve body problem, neither of which would require a rebuild. Rebuilds mostly just replace clutches and rubber seals, so I am not sure you would need one.