Several Ford Bronco owners claim that after welds broke on their SUVs dealers are refusing to cover repairs under warranty. They say the incidents occurred when they went off-roading. Forums suggest the problem is the Trail Turn Assist (TTA) system. 

TTA reduces turning radiuses in tight off-road conditions. It works by engaging the inside rear wheel brake. Ford says it enhances “low-speed, high steering angle maneuvers.” But the Bronco owners allege this leads to welds on the rear axle breaking. 

A Bronco Forum says the problem happens because of a combination of only one brake engagement and the rear axle’s tendency to wrap or twist. It results in welds on the Dana Spicer axle housings breaking, it is alleged. Since the brake is attached to the axle housing, and the axle’s tendency is to rotate, twisting occurs. 

One of the issues is whether to use TTA on hard, rough surfaces rather than only soft dirt, pebbles, and sand. The tire can slip easier in the soft stuff, whereas it tends to bite on hard rough surfaces. To be clear, there is no drive torque to the side with brake engagement, so the tire is only dragging. 

Ford even gives a warning about this. “Do not use trail turn assist on dry, hard surfaced roads. Doing so can produce excessive noise, increase tire wear, and may damage the drive line, or braking components. Trail turn assist is only intended for slippery, or loose surfaces.”

A couple of fixes are to weld completely around housing joints, or bracing the housing and pumpkin. The housing tubes only have two plug welds at the top and bottom of the pumpkin just inside where the axle tube enters the cast housing. This is typical of most rear axle assemblies. 

Larger diameter off-road tires only exacerbate the problem. That’s because they increase torque with a taller diameter. So this might be another problem causing dealers to refuse to cover the issue under warranty.  

Another possibility, if a dealer refuses to fix the problem under warranty, is to just take your Bronco to another dealer. But in this situation, that’s not the easiest, since the SUV is inoperable. With the repair done by an outside source, you get your Bronco back sooner than waiting weeks or months without it.

The elephant in the room is the welds themselves. Is there a possibility the weld did not penetrate or is otherwise defective? And also, how smart is it to offer something that potentially has a fine line between being a convenience and the reason a component breaks? We’ll update this post when more information is forthcoming.