How Bad Is It? The 3 Stages Of Transmission Diagnosis

If you drive a vehicle with an automatic transmission, there's nothing worse than noticing slipping, grinding, or other significant shifting issues. Automatic transmissions are sophisticated components with many moving parts, making them costly to repair or rebuild. As a result, most drivers start immediately thinking of the pain in their wallets whenever they experience a transmission issue.

Fortunately, not all transmission issues are quite so dramatic. When you take your vehicle in for a repair, the technician will first answer one question: how bad is it? While every shop's diagnostic procedures will be a little different, this guide will describe the three general stages used to isolate and identify problems with your transmission.

Stage 1: The Basics

If you're lucky, your transmission problem is a relatively minor issue that won't require an extensive rebuild or replacement. Most shops will begin with the basics before moving on to more complicated diagnostic procedures. These steps include checking your fluid level and fluid condition, as well as confirming an adequate and reliable electrical system.

These steps are critical since transmissions require an adequate amount of clean hydraulic fluid for lubrication, cooling, and shifting. If ignored, low fluid levels or contaminated fluid can affect your transmission or even cause more severe damage. Likewise, battery or charging system issues can impact the behavior of your transmission's electronic control systems.

Stage 2: Deeper Investigation

If there are no immediate signs of trouble, most technicians will look for more subtle issues. These can include evidence of leaking, faulty electrical connections to the transmission, or torn or damaged wires. These relatively minor problems can result in the usual host of transmission symptoms, so it's essential to check for them before moving on to more expensive repairs.

In some cases, these signs can be subtle. For example, electrical wires that came loose from a bracket may rub across nearby metal, creating a short and impacting the transmission's performance. Old, failing transmission cooler lines are another potential source of trouble. While these issues can sometimes be challenging to find, they're often relatively inexpensive to repair.

Stage 3: Transmission Removal

The last step is to pull the transmission from the car and begin disassembly. Repairs that require disassembling and rebuilding the transmission tend to be costly, so this is often a final resort when no other issues are apparent. Your shop may also skip some of the above diagnostic steps if a computer code convinces them that an internal transmission issue is likely to blame for your trouble.

While repairing a transmission isn't a cheap procedure, it's also not one you should ignore. Driving with a failing transmission can rapidly cause more damage, resulting in even more expensive repairs in the future. If you notice any symptoms of transmission failure with your car, always have a qualified transmission repair shop perform a step-by-step diagnosis as soon as you can.

For more information, contact a local auto shop that offers transmission services.


Share