What exactly does Sport Mode do?

[ryoung57]

Does Sport change something within the ELSD? I notice the rear inside tire chirps/shudders while turning in sport. Doesn’t matter if it’s in 2H or 4A.

It also does it in Sand and Mud modes

 

[rd618]

No, it does not change the ELSD. It does engage the center diff from the onset in all 3 of those modes (sport, Sand, and Mud) It does make throttle response more linear so you likely have more acceleration at the same throttle position.
If inside tire chirps, you over-powered it (i.e. accelerating more than the friction of the tire can maintain with the turn radius). The inside tire always spins slower than the outside tire, and differentials are designed to enable that.
if you notice odd behavior, like tires skipping or binding, your diffs are locked which can cause failure if you keep doing that.

 

[ryoung57]

No, it does not change the ELSD. It does engage the center diff from the onset in all 3 of those modes (sport, Sand, and Mud) It does make throttle response more linear so you likely have more acceleration at the same throttle position.
If inside tire chirps, you over-powered it (i.e. accelerating more than the friction of the tire can maintain with the turn radius). The inside tire always spins slower than the outside tire, and differentials are designed to enable that.
if you notice odd behavior, like tires skipping or binding, your diffs are locked which can cause failure if you keep doing that.

It’s happening at barely more than idle. I’ll have to take it in, which is bs because I’ve only had the stupid thing 3 days.

 

[rd618]

It’s happening at barely more than idle. I’ll have to take it in, which is bs because I’ve only had the stupid thing 3 days.

There are a lot of variables here, so if you can replicate it for them it would be good to understand what they say.

 

[ryoung57]

There are a lot of variables here, so if you can replicate it for them it would be good to understand what they say.

I’m trying to eliminate as many of those variables as possible. It really feels like the differential is hanging up, forcing the inside tire to try to turn as fast as the outside. It seems to be worse on the drivers side.

 

[rd618]

I’m trying to eliminate as many of those variables as possible. It really feels like the differential is hanging up, forcing the inside tire to try to turn as fast as the outside. It seems to be worse on the drivers side.

The elsd should only engage with current. Try to pull the fuse or disconnect the connector on the rear axle case. I'm assuming you do not have the locker engaged (green icon on dash with x between rear wheels)

 

[ryoung57]

The elsd should only engage with current. Try to pull the fuse or disconnect the connector on the rear axle case. I'm assuming you do not have the locker engaged (green icon on dash with x between rear wheels)

I just got back from driving it around in circles in a parking lot for half an hour. I’m more stumped now than before.

At take off, almost exclusively when turning left, it will buck and shake from the rear. It happens sometimes in normal or eco, almost every time in sport. When turning tight circles, there is a constant rubbing sound from under the car.

This may be two different things or somehow connected.

 

[LegalBrief]

Sounds like you’re in 4H on dry pavement. Set it to 2H and see what the truck does.

 

[SyndicateZ]

Anytime the vehicle is in 4x4 mode you will hear crunching while on regular pavement while turning slowly especially. My navigator does this as well

 

[ryoung57]

Sounds like you’re in 4H on dry pavement. Set it to 2H and see what the truck does.

I agree, it does. Problem is that it’s not on 4H. It’s acting this way in 2H and in 4A.

 

[rd618]

I just got back from driving it around in circles in a parking lot for half an hour. I’m more stumped now than before.

At take off, almost exclusively when turning left, it will buck and shake from the rear. It happens sometimes in normal or eco, almost every time in sport. When turning tight circles, there is a constant rubbing sound from under the car.

This may be two different things or somehow connected.

Bring it for service. The symptoms you’re describing are a faulty differential.

 

[Left Coast Geek]

Sport mode enables 4A on my 2019, but I haven't noticed any differential binding even under heavy throttle while turning sharply. 2019 limited stealth with hd tow. 4A does seem to have just a bit of torque steer, more than my wife's Mercedes E350 4Matic, which is always in "4A"

 

[JimmyM]

I have a '23 Stealth Package (Not SPP) with the CCD & eLSD. If I get on it in sport mode from a stop at a turn I will hear the right side tire scuff, but it only does it if I get on it a bit too much.
But you bring up a good question. What does sport mode do?
I know throttle response/mapping is improved and shift points change.
It appears that the eLSD isn't involved and is a manual on/off thing.
But does it change the damping of the CCD system?

 

[Christopher D]

In my experience, it basically turns my Expedition into a race car. Impressive acceleration and downshifting.

 

[dlcorbett]

I have a '23 Stealth Package (Not SPP) with the CCD & eLSD. If I get on it in sport mode from a stop at a turn I will hear the right side tire scuff, but it only does it if I get on it a bit too much.
But you bring up a good question. What does sport mode do?
I know throttle response/mapping is improved and shift points change.
It appears that the eLSD isn't involved and is a manual on/off thing.
But does it change the damping of the CCD system?

Your right it changes throttle mapping and steering heft. If you have ccd, it tightens the suspension to a considerable degree. I actually prefer the sport mode ride in city streets, it's more comfy to me.

 

[ryoung57]

Your right it changes throttle mapping and steering heft. If you have ccd, it tightens the suspension to a considerable degree. I actually prefer the sport mode ride in city streets, it's more comfy to me.

I prefer it too, but I don't prefer the rear axle hopping like it's trying to escape every time I turn.

If you put it in sport mode and make a tight left turn circle, does it sound like something's rubbing back there?

 

[VBreithaupt]

Is the rear locking differential button on? It sounds terrible when that is on and you are turning. My dog steps on that one every once in a while

 

[dlcorbett]

I prefer it too, but I don't prefer the rear axle hopping like it's trying to escape every time I turn.

If you put it in sport mode and make a tight left turn circle, does it sound like something's rubbing back there?

Mines doesn't, but mines is rwd

 

[JimmyM]

When I go into sport, i switch it back to 2H. I still need to test out the different modes and tire scrubbing under controlled conditions.

I love the way CCD tames body movement.

 

[ryoung57]

In my experience, it basically turns my Expedition into a race car. Impressive acceleration and downshifting.

You don’t have much experience with race cars do you? . (J/k, it is surprisingly quick for such a big vehicle)