* Damage to the transmission: The most likely scenario is that you've removed a bolt that's *not* designed to be removed for draining fluid. This could be a bolt holding a case section together, a bolt securing an internal component, or even a bolt that is part of a critical internal mechanism. Removing it can cause leaks, internal damage, and complete transmission failure. The transmission might not function at all, or it might only function poorly, leading to eventual catastrophic failure.
* Fluid Loss from another system: You might have inadvertently drained fluid from a completely different system, such as the differential, power steering, or even the engine oil (though this is less likely as engine oil drain plugs are usually quite distinct). This will obviously lead to problems in that system.
* Difficulty Re-assembling: Even if you manage to remove the "wrong" bolt without immediate catastrophic damage, getting it back in correctly might be difficult or impossible, possibly requiring specialized tools and expertise. The threads might be damaged, requiring more extensive repairs.
* Safety Hazard: A malfunctioning transmission can affect vehicle control, leading to dangerous situations on the road.
In short: Removing the wrong bolt on a manual transmission is a serious mistake that can lead to costly repairs or even the need for a transmission replacement. If you're unsure where the drain bolt is located, consult your vehicle's repair manual or seek professional assistance from a qualified mechanic. Attempting this repair without the proper knowledge is strongly discouraged.
