Your semi truck’s transmission is one of its most important—and complex—systems. It keeps your truck moving smoothly, especially when you’re hauling heavy loads through the busy roads of San Antonio, TX. When something goes wrong with the transmission, ignoring it can lead to serious damage, lost time, and high repair costs.
At B&V Motor Service, we specialize in diagnosing and repairing semi truck transmissions to keep drivers on the road and out of the shop. In this blog, we’ll go over the top signs that your transmission may be in trouble and when to schedule a repair to avoid a costly breakdown.
Why Transmission Health Matters
The transmission is responsible for shifting gears and transferring power from the engine to the wheels. It takes a beating every day—especially in a city like San Antonio, where traffic, high temperatures, and stop-and-go driving are common. Without proper maintenance or early repairs, your transmission can wear down quickly, affecting your truck’s performance and fuel efficiency.
Catching transmission problems early can make all the difference. Here are the warning signs every semi truck driver should watch for:
1. Slipping Gears
If your truck slips out of gear while driving or has trouble staying in gear, that’s a red flag. Gear slippage can be dangerous, especially when climbing hills or merging onto highways like I-10 or I-35 in San Antonio.
What It Means:
Low transmission fluid, worn clutch components, or internal damage.
2. Delayed or Rough Shifting
Are you noticing delays when shifting gears or a jerking sensation during transitions? This can indicate wear within the transmission system.
What It Means:
Issues with transmission fluid, torque converter, or internal mechanical parts.
3. Unusual Noises
Grinding, whining, or clunking sounds when your truck shifts gears are all signs something isn’t right. Noises from under the cab may seem small at first but often point to larger issues.
What It Means:
Worn gears, loose components, or internal transmission damage.
4. Leaking Transmission Fluid
A red or dark fluid under your truck is likely a transmission leak. This fluid keeps everything inside the transmission lubricated and cool.
What It Means:
Cracked seals, loose connections, or a failing gasket. A leak left unaddressed can cause the transmission to overheat or seize up.
5. Dashboard Warning Lights
If the check engine light or a transmission-related warning light comes on, don’t ignore it. These lights often detect problems before you feel them.
What It Means:
The truck’s onboard diagnostics system (ECM) has detected a fault in the transmission or related sensors.
6. Burning Smell
A burning odor while driving could be caused by overheating transmission fluid. This is common in hot environments like San Antonio, TX, especially during summer months.
What It Means:
Old or low fluid that needs to be changed—or an overheating transmission needing urgent attention.
What to Do If You Notice These Signs
If you notice any of these warning signs, it’s best to bring your truck in for service right away. At B&V Motor Service in San Antonio, we offer complete semi truck transmission repair, diagnostics, and maintenance. Our experienced technicians use advanced tools to find and fix the problem quickly so you can stay on schedule.
We handle both manual and automatic transmissions and work with all major truck brands. Whether you’re driving a Freightliner, Kenworth, Volvo, or Peterbilt, we’ve got you covered.
Final Thoughts
Transmission problems don’t go away on their own—they only get worse. If you’re experiencing gear issues, fluid leaks, or strange noises, don’t wait until you’re stuck on the side of the road. Getting early transmission repair can save you thousands in the long run and prevent costly downtime.
For trusted semi truck transmission repair in San Antonio, turn to B&V Motor Service. We’re committed to keeping your truck running strong with honest service, skilled repairs, and fast turnaround times. Call us today or visit our shop in San Antonio, TX to schedule your transmission inspection.