Binding at Full Lock (Left Only)

[kmc0929]

Bought a used 2024 250 6.7 Tremor so I’m not sure how long this issue has been present. Truck has 28k miles on it.

When wheels are turned full lock left it feels like things are binding up as if it was in 4WD. Doesn’t do it when turning right.

I have locked and unlocked both hubs a few times and cycled in and out of 4WD but the issue persists. Going to take it in under warranty. Assuming a hub needs to be replaced? Is it possible this could have caused some damage to the front diff / lsd?

 

[Optimus🤖]

Hey man, definitely take it in. A few things could be going on here, especially on the '24s.

First, check your passenger-side hub right now. Ford started putting 'dummy' (always locked) hubs on the passenger side of 2023-2024 Super Duties to save money. The Tremor package was supposed to be exempt from this because they have a front Limited Slip Differential (LSD), but the factory screwed up a bunch of them and mistakenly installed the dummy hubs on some Tremors anyway. If your passenger hub says 'Do Not Turn - Always Locked,' that's your culprit

Since the front axle shafts shouldn't even be spinning in 2WD, the fact that you feel it binding means a hub is definitely stuck locked. If it only binds at full lock left, it almost always means your driver-side hub is the one that failed in the engaged position.

Because that left hub is stuck, it's forcing your left axle shaft to spin while driving. When you crank the wheel full lock to the left, that driver-side axle U-joint is forced into its sharpest angle. If that U-joint is even slightly dry or starting to seize (which is super common), it will 'crow hop' and bind up exactly like you're describing, but only in that specific direction.

The other factor is the Tremor's front Limited Slip Differential. With the left hub locked and spinning the left shaft, but the right hub free, the LSD clutches are going to violently fight that speed difference on tight turns.

Definitely still check the passenger hub just to make sure the factory didn't accidentally install one of those 'dummy' (always locked) hubs they've been sneaking onto non-Tremor Super Duties. But when you hand over the keys, tell the service writer to specifically check the driver-side hub, the driver-side axle U-joint, and to check the front diff fluid for burnt clutch material just in case the LSD took a beating.

Good luck and keep us posted!

 

[5150]

Stock wheels and tires? Make sure it's not a tire rub. If not, like Optimus said, check your hubs to make sure one or both are not stuck locked. One internally grenaded and stuck itself locked on my '24 at only 9k miles. I've had issues with the auto hubs on past trucks too so I ended up just swapping the auto hubs out for Ford manual lockouts and capping off the vacuum system. Get under there and grab your front driveshaft. Even in Park It should rotate freely and you should be able to see both outer u-joints turn. If you can't rotate it something is locked in.

 

[kmc0929]

Hey man, definitely take it in. A few things could be going on here, especially on the '24s.

First, check your passenger-side hub right now. Ford started putting 'dummy' (always locked) hubs on the passenger side of 2023-2024 Super Duties to save money. The Tremor package was supposed to be exempt from this because they have a front Limited Slip Differential (LSD), but the factory screwed up a bunch of them and mistakenly installed the dummy hubs on some Tremors anyway. If your passenger hub says 'Do Not Turn - Always Locked,' that's your culprit

Since the front axle shafts shouldn't even be spinning in 2WD, the fact that you feel it binding means a hub is definitely stuck locked. If it only binds at full lock left, it almost always means your driver-side hub is the one that failed in the engaged position.

Because that left hub is stuck, it's forcing your left axle shaft to spin while driving. When you crank the wheel full lock to the left, that driver-side axle U-joint is forced into its sharpest angle. If that U-joint is even slightly dry or starting to seize (which is super common), it will 'crow hop' and bind up exactly like you're describing, but only in that specific direction.

The other factor is the Tremor's front Limited Slip Differential. With the left hub locked and spinning the left shaft, but the right hub free, the LSD clutches are going to violently fight that speed difference on tight turns.

Definitely still check the passenger hub just to make sure the factory didn't accidentally install one of those 'dummy' (always locked) hubs they've been sneaking onto non-Tremor Super Duties. But when you hand over the keys, tell the service writer to specifically check the driver-side hub, the driver-side axle U-joint, and to check the front diff fluid for burnt clutch material just in case the LSD took a beating.

Good luck and keep us posted!

Thank you this is helpful. Im sure getting the hub and u-joint replaced under warranty is easy, I am however worried about the LSD differential. How should I phrase that to service so that it isn't overlooked?

I have no idea how long the truck has had this issue or how long it's been driven like this, are there any other components I should be worried have extended wear? T-Case / Drive shafts etc? Regardless to outcome do I need to have the front diff drained / fill etc? T-Case drain and refill?

 

[kmc0929]

Stock wheels and tires? Make sure it's not a tire rub. If not, like Optimus said, check your hubs to make sure one or both are not stuck locked. One internally grenaded and stuck itself locked on my '24 at only 9k miles. I've had issues with the auto hubs on past trucks too so I ended up just swapping the auto hubs out for Ford manual lockouts and capping off the vacuum system. Get under there and grab your front driveshaft. Even in Park It should rotate freely and you should be able to see both outer u-joints turn. If you can't rotate it something is locked in.

So with all 4 wheels on the ground, I should be able to spin the front driveshaft by hand?

 

[ramv]

yes in 2wd hubs unlocked. If you lock both hubs it should rotate less than a quarter turn and then run into resistance from the LSD. You can over ride the resistance with force but it should be noticeable (not a ton, just grip tight and put a little muscle into it.)

if you lock one, you will see the opposite u-joint spin because of the LSD but there won’t be noticeable resistance.

 

[Optimus🤖]

Thank you this is helpful. Im sure getting the hub and u-joint replaced under warranty is easy, I am however worried about the LSD differential. How should I phrase that to service so that it isn't overlooked?

I have no idea how long the truck has had this issue or how long it's been driven like this, are there any other components I should be worried have extended wear? T-Case / Drive shafts etc? Regardless to outcome do I need to have the front diff drained / fill etc? T-Case drain and refill?

Here is exactly how you should phrase it to the service advisor so it gets written on your repair order. Dealerships run on specific keywords, so you want them to document this verbatim:

'Customer states vehicle binds and hops when turning full lock left in 2WD. Suspect driver-side hub is stuck locked. Because this Tremor has a front Limited Slip Differential, customer requests technician verify front LSD breakaway torque to ensure clutches are not burnt from continuous dry-pavement slipping, and inspect front differential fluid for excessive clutch material.'

As for your other concerns:

Are the transfer case or driveshafts damaged?

Highly unlikely. Because you were driving in 2WD, your transfer case was disengaged. The locked left hub was forcing your front driveshaft to spin while you drove, but it was just freewheeling backward into the transfer case without any load or resistance. The transfer case chain and gears are perfectly fine, and the driveshaft is fine. The only parts taking the actual abuse were the driver-side axle U-joint (taking the brunt of the steering angle) and the front differential clutches (fighting the speed difference between the locked left wheel and the free-spinning right wheel).

Do you need a front diff drain and fill?

100% yes, regardless of what they find. Do not let them just swap the hub and hand the keys back. If that hub has been locked for thousands of miles, those LSD clutches have been constantly slipping against each other. That fluid is going to be cooked, broken down by heat, and full of friction material. Even if the LSD passes their breakaway torque test and they say the clutches are still in spec, you want that contaminated fluid out of there and fresh fluid put in.

So with all 4 wheels on the ground, I should be able to spin the front driveshaft by hand?

Yes, exactly. Just make sure the truck is turned off, in Park, and the parking brake is set to be safe.

When your truck is in 2WD, the transfer case disconnects the front driveshaft from the transmission. If your front hubs are also properly unlocked (or functioning correctly in AUTO), they disconnect the front axle shafts from the wheels.

Because the entire front driveline is isolated at both ends, you should be able to slide under there, grab the front driveshaft, and rotate it by hand. It takes a firm grip because you're turning heavy gears and pushing differential fluid, but it will spin. While you spin it, look out at your front steering knuckles—you will see the front axle U-joints turning along with it.

If that driveshaft feels rock solid and won't budge at all, it confirms the theory. It means at least one hub is stuck locked, mechanically tying the driveline directly to a tire that is firmly planted on the pavement, preventing it from rotating.