WTF… Truck rolling/sliding backwards in park

[Dannyboy80]

Ok, so, wife and I get home from dinner last night and go to park our truck in our incline sloped driveway. After engaging the park brake, putting it in park, and letting off the brake it started rolling or sliding backwards…

My first thought was “damn, it’s icy!” BUT why the heck would it hold itself in place until I took my foot off the brake THEN start moving while in park with the parking brake engaged? Unfortunately, I didn’t think to get out and see if it was rolling or sliding so I can’t say which was actually occurring… Just parked it on flat ground in front of the house and called it a night.

Is it possible that the front tires had traction while the rears were on ice, causing it not to hold once off the foot brake? Or maybe the slight motion of the truck settling back after letting off the brake causing it to slide?

Going to see if I can recreate today but don’t know if it’s still as slick as it was last night.

Sponsored

 

[Ford Motor Company]

Ok, so, wife and I get home from dinner last night and go to park our truck in our incline sloped driveway. After engaging the park brake, putting it in park, and letting off the brake it started rolling or sliding backwards…

My first thought was “damn, it’s icy!” BUT why the heck would it hold itself in place until I took my foot off the brake THEN start moving while in park with the parking brake engaged? Unfortunately, I didn’t think to get out and see if it was rolling or sliding so I can’t say which was actually occurring… Just parked it on flat ground in front of the house and called it a night.

Is it possible that the front tires had traction while the rears were on ice, causing it not to hold once off the foot brake? Or maybe the slight motion of the truck settling back after letting off the brake causing it to slide?

Going to see if I can recreate today but don’t know if it’s still as slick as it was last night. Just a weird situation I’ve never before experienced and hoping I don’t have a new transmission issue!

Hey there! I can look into your concerns on my end. Can you send over a DM with your VIN and Ford dealer info?

 

[Tosh]

I haven't had that experience with my truck. I don't know if it makes any difference, but my habit is to put on the parking brake while holding the footbrake, with the transmission in neutral, then shift into park. It's from all the years I drove a stick.

I can remember once or twice when I didn't see the "parking brake on" message after pulling the lever, and I had to pull it again. I reckoned that was my error.

 

[Porpoise Hork]

My driveway is not as sloped as yours so I rarely engage the parking brake and it will usually rock back on the park gear when lifting off the brake. When I do use the parking brake I can hear the actuators kick on from inside the truck, and it won't move. It's possible that they hadn't fully engaged when you released the brake causing it to rock back.

 

[BCP28]

My driveway isn't super sloped, but has enough of a slope that this has happened a few times with some snow/ice in the driveway. Since the rear is lighter than the front, the rear is more prone to slipping, which is the axle that is braked when in Park or with the e-brake

In Park, all it takes is one rear wheel not having enough traction for the vehicle to roll because of the differential. Setting the e-brake helps, but leaving in 4x4 usually does the trick if it's slick.

 

[JIMFOUNTAIN]

My first thought was “damn, it’s icy!” BUT why the heck would it hold itself in place until I took my foot off the brake THEN start moving while in park with the parking brake engaged?

Foot on the brake = all 4 tires holding.
Park (with parking brake) = 2 rear tires holding.
If you park in 4WD you can add a front tire to what is holding.

I suspect your rear tires were on ice.

Raptors and Tremors with the limited slip characteristics of the optional front diff can add 2 front tires in 4WD. I am pretty sure that 4A (TOD transfer case) isn't engaged/locked when power is off so 4WD, not 4A.

I am not sure if the electrical locking option on the open rear diff stays engaged/locked when power is off. From what I can tell it does but does anyone know for sure?

For me a locked diff would be a better option than setting the parking brake. I tend to not set parking brakes in hard freezing conditions... I have had brakes get hot then wet then hard freeze overnight. Had to goto low range to get enough torque to break free and drive the next morning.

 

[Dannyboy80]

Ohhhh this makes all the sense in the world and I feel foolish for not thinking it through… Thank you both! I’ll give it another shot and see if leaving it in 4 High helps.

 

[Dannyboy80]

Tested it again and, sure enough, rear wheels are locked up and sliding while fronts are rolling. Attempted putting it in 4wd and it didn’t make a difference, unfortunately… But at least I know it’s not the transmission. Kinda lame that I can’t park my truck in the driveway when it’s icy… Our old Grand Cherokee had zero issues. Just a better built rig for the snow, I suppose.

 

[Porpoise Hork]

Tested it again and, sure enough, rear wheels are locked up and sliding while fronts are rolling. Attempted putting it in 4wd and it didn’t make a difference, unfortunately… But at least I know it’s not the transmission. Kinda lame that I can’t park my truck in the driveway when it’s icy… Our old Grand Cherokee had zero issues. Just a better built rig for the snow, I suppose.

Glad it's not the transmission or parking brake.

I'd put more blame on the tires failing to hold on the F150 than the Jeep.

Well... If you have different tires now than on that one that is.

 

[Dannyboy80]

Glad it's not the transmission or parking brake.

I'd put more blame on the tires failing to hold on the F150 than the Jeep.

Well... If you have different tires now than on that one that is.

For real - Would’ve been a major bummer if it was the trans!

Don’t think it’s the tires. To the other gents’ points earlier in this thread, it seems that the locked wheels on the super light ass end of this thing can’t hold the heavy front end.

Just means I can’t park my truck in my driveway after a good snow

 

[HammaMan]

If ice is regularly on the driveway, you're too far north

As you've found, park only works on the rears. I have found that if I'm on an incline, or the truck bounces post brake release, it will often automatically engage the parking brake.

It will also auto park brake if you open the door while in drive -- it engages the parking brake and puts it into park.

Another 'feature' I've found from my habits in the mach e transferring to the F150 (I use auto hold feature) and I don't use park. I simply pull into a spot and turn off the vehicle. Both go into park automatically.

 

[Mdhfinsc]

That’s okay. I already have an open case with you guys that you’ve done nothing about. No need to pile them up!

I believe this is just a bot . Automatically replying to posts. Nothing gets done anyway. Until sales plummet then they will.

 

[EFudd]

I have the same problem with my F350 parking. With an empty bed, there is not much load on the rear tires. I put 1/8 cord of wood in the back for winter, and all is fine

Sponsored