When a car is having trouble shifting, one of the first questions drivers often have is regarding how long it'll take to fix the issue. Transmission problems range from the downright simple to the dreadfully complex, but there are a few factors that can help a professional guess how complicated the job is going to be.

Diagnosis

A couple of hours usually go into running diagnostics. With nearly all modern vehicles, the car's onboard computer is linked to a scanner that pulls errors from the system. These codes provide a starting point for figuring out what might be wrong.

Where the diagnostic process can run a little longer is if a code doesn't lead to a specific answer. The staff at the transmission shop may have to do a little research and even try a few things with the transmission itself to establish what's wrong.

Electronic Issues

This is usually the lucky duck scenario, presuming the problem isn't the computer system that sends signals to the transmission. It's not uncommon for relays to go dead, and replacing them is one of the simpler issues with a transmission. Once the parts come in, these problems are often fixed in a day or two.

Mechanical Trouble

If you've had a transmission take weeks to get fixed by a professional, it almost certainly was a mechanical issue. Performing repairs requires pulling the transmission out of the car, usually using a lift to get under the car and other equipment to keep the transmission stable when it drops. Unsurprisingly, pros tend to take their time removing transmissions because they have many mount points that attach to the engine and the axles. There may also be a driveshaft to disconnect.

Repairs often require opening the transmission up to see what's going on inside. If the flywheel is cracked or has broken teeth, for example, this requires even more unbolting of components. When a new flywheel is installed, everything has to be bolted up again and new seals are usually installed.

Damage to the transmission case can be tricky to deal with, too. If there's a hole in the case, for example, the technician has to establish whether it's a puncture that can be welded or if the problem is due to rust and requires more attention. Most technicians still drop the transmission out in these scenarios because of the risks posed by welding close to other components on a vehicle.