2013-2018 Toyota Avalon Back Glass: Defroster Grids, Leaks, and Sunshade Issues

Symptoms of a Failing Back Glass

Visible Cracks or Shattering

The most obvious sign of failure is physical damage. This can range from a small chip or crack to a completely shattered window. Unlike laminated windshields that tend to hold together when damaged, the tempered back glass will break into many small fragments. This can happen from an impact or, in rare cases, due to thermal stress or a manufacturing defect.

Rear Defroster Not Working

If you press the rear defroster button and the frost or fog on the back glass doesn't clear, the system has failed. This can be caused by several issues, including a blown fuse, a bad relay, or a problem with the glass itself. Often, one or more of the thin, orange or brown grid lines on the glass is broken. A single scratch or break in a line can cause the entire grid or a section of it to stop working. The electrical tabs where the vehicle's wiring connects to the grid can also become detached, cutting power to the system.

Water or Wind Leaks

A wet headliner near the rear of the car or moisture inside the trunk can indicate a leak around the back glass seal. Over time, the urethane adhesive that holds the glass in place can degrade, or it may have been installed improperly during a previous replacement. This can create gaps that allow water to seep in, potentially causing water damage, mold, and rust. You might also hear excessive wind noise from the rear of the car while driving.

Known Issues, Recalls, and TSBs

While there are no major recalls or widespread complaints about the back glass itself on the 2013-2018 Toyota Avalon, there is a very common issue with the optional power rear sunshade that is often mistaken for a window problem.

Common Problem: Power Rear Sunshade Failure

Many Avalon models in this generation are equipped with a power sunshade that retracts up and down in front of the back glass. The motor and gears for this assembly are known to fail, causing a loud grinding or buzzing noise when the car is put in reverse (which automatically lowers the shade) or when the control button is pressed. The shade may get stuck in the up, down, or a partial position. Toyota issued a Technical Service Bulletin (TSB), T-SB-0157-14, for 2013-2014 models where the sunshade may rise on its own in high temperatures. Repairing this assembly can be expensive, often costing over $1,500 at a dealership. This is a failure of the sunshade mechanism, not the back glass.

Recalls for Other Systems

The 2013-2018 Avalon has been subject to other recalls, including for the airbag control unit and the Pre-Collision System (PCS), but none of these directly involve the back glass.

Buying a Used 2013-2018 Avalon Back Glass

A used OEM back glass can be a cost-effective alternative to a new part, but careful inspection is critical to ensure you get a good one. OEM glass guarantees a perfect fit, which is essential for preventing leaks and wind noise.

1. Inspect the Defroster Grid: This is the most important check. Carefully examine every horizontal grid line from one side to the other. Look for any scratches, breaks, or flaking. A single deep scratch from loading cargo can sever a line and disable the defroster.
2. Check the Electrical Connectors: Locate the two metal tabs, one on each side of the glass, where the defroster wiring connects. Ensure these tabs are firmly attached to the glass and not broken off or damaged. Re-attaching a broken tab is difficult and often fails.
3. Look for Scratches and Damage: Check the entire surface of the glass for deep scratches or chips, especially near the edges where they can turn into cracks over time. Minor surface scuffs are usually acceptable, but deep gouges are a red flag.
4. Verify Part Numbers: The primary OEM part number is 64801-07011, which supersedes the earlier number 64801-07010. The industry-standard NAGS number is FB25756GT. Ensure the glass you are buying is specified for the 2013-2018 Avalon to guarantee correct fitment.

Replacement Cost Comparison

The cost to replace the back glass can vary significantly based on the type of glass used and labor rates in your area. The power sunshade is a separate component and its repair is not included in these costs.

Installation Details and Difficulty

Replacing a modern back glass is a job best left to professionals.

• Difficulty Rating: 5 out of 5 (Professional Recommended)
• DIY Feasible: No

The process involves removing interior trim panels, carefully cutting the old urethane adhesive seal without damaging the vehicle's paint, cleaning the frame meticulously, applying a new bead of urethane with a specialized primer, and setting the new glass perfectly in place. The urethane must then cure for several hours before the vehicle is safe to drive. An improper installation can lead to dangerous structural failure in an accident, as well as serious water leaks and wind noise.

Frequently Asked Questions (FAQ)