Here's what you need to consider:
* Symptoms before and after the rebuild: What transmission problems did you have *before* the rebuild? Did those problems persist *after* the rebuild? If the problems are entirely new, it's less likely the torque converter is the culprit. If the same or similar problems remain, it's more plausible.
* Mechanic's explanation: Did the mechanic provide a detailed explanation of *why* they believe the torque converter needs replacing? Did they perform any diagnostics to confirm this, such as checking the torque converter for damage or checking the fluid for metal shavings? A reputable mechanic will be able to explain their findings clearly.
* Torque converter condition during the rebuild: Did you personally inspect the torque converter when you rebuilt the transmission? If so, was there visible damage? If not, you have less information to go on.
* Mechanic's reputation: What's the reputation of this mechanic? Are they known for honest work? Online reviews might help you determine this.
* Second opinion: Getting a second opinion from a different reputable mechanic is crucial. Describe the symptoms and have them inspect the vehicle. This will help determine if the torque converter truly needs replacement.
In short: Don't automatically assume the mechanic is dishonest, but also don't take their word for it without evidence and a second opinion. The cost of a torque converter replacement is significant, so thorough investigation is warranted. A second opinion from an independent mechanic will give you the most reliable information.
