Transmission Troubles? How to Spot the Early Warning Signs

Your truck’s transmission is one of its most vital parts—and one of the most expensive to repair or replace. To prevent this from occurring, it is a good idea to be aware of the early warning signs of potential transmission problems, whether you are running long or local hauls. At Interline Truck & Trailer Repair Services, we’re here to help you prevent problems before they become catastrophes.

Here are some warning signs to look out for in transmission problems with heavy-duty and commercial trucks.

Unusual Noises: If you hear any grinding, whining, clunking, or humming sounds, in particular when you change gears, it’s time to take a look. These sounds can indicate:

• Worn gear teeth
• Low/dirty transmission fluid
• Worn bearings, phosphorization inside the pump

Don’t overlook mysterious noises; they’re usually a sign that internal components are under duress.

Difficulty Shifting Gears

If your truck hesitates, jerks, or slips when changing gears, that’s a problem. This could point to:

• Worn clutch parts (manual transmissions only)
• Low transmission fluid
• Means It’s Time To Replace It: A bad cyprinoid or sensor (for automatics)

Smooth, responsive shifts are an essential aspect of transmission health — if that changes, get it checked out.

Leaking Transmission Fluid

Transmission fluid is usually red or brown and has a sweet or burnt odor. If you see pooling beneath the vehicle or any sign of fluid on the transmission housing, you may have:

• Seal or gasket failure
• Cracked transmission casing
• Loose transmission pan bolts

A loss of fluid can cause overheating and internal damage, so don’t put off those repairs.

Burning Smell

While the smell of burning is typical, particularly during long hauls or in traffic, here’s what it could be a sign of:

• Overheated transmission fluid
• Friction from slipping gears
• Fluid contamination

Overheating can cause the transmission fluid to break down, leading to transmission failure.