Sponsored

Cybertruck has no Parking Pawl in its Tranmission. Lightning does.

StevenC56

Well-known member
First Name
Steven
Joined
Sep 13, 2024
Threads
3
Messages
141
Reaction score
87
Location
Fresno California
Vehicles
2024 Lightning Lariat Avalanche, 2017 Explorer Platinum
Occupation
Retired
That's not what he was saying....
So you guys think that the CT wouldn't be a safety risk if either the electrical system that powers the park brake fails or the park brake's mechanics themselves failed?
Sponsored

 
OP
OP

RickKeen

Well-known member
First Name
Rick
Joined
Sep 14, 2022
Threads
42
Messages
507
Reaction score
649
Location
Minnesota
Vehicles
F150L SR Pro
Occupation
sw engineering manager,
In the thread on the Cybertruck forum, it was mentioned that the Cybertruck itself can sometimes warn the driver that the brakes may not hold when parking on a hill. That is what started the discussion over there.

In the Munro video, they mention that "other" manufacturers do not include the expensive park brake pawl in their electric drive units. By "other", I took that to include the Tesla, but I have not gone and confirmed that in their Tesla Cybertruck videos.

Nobody on the CT forum chimed in to claim the CT has a parking pawl mechanism in its transmission...

The discussion started in a thread talking about launching boats on a boat ramp, here:
https://www.cybertruckownersclub.co...rtruck-was-great-experience.31335/post-550138
 
Last edited:
OP
OP

RickKeen

Well-known member
First Name
Rick
Joined
Sep 14, 2022
Threads
42
Messages
507
Reaction score
649
Location
Minnesota
Vehicles
F150L SR Pro
Occupation
sw engineering manager,
Additionally, there is this tidbit in the Cybertruck manual:

Warning
Your Cybertruck may display an alert if the road is too steep to safely park, or if the parking brakes are not properly engaged. These alerts are for guidance purposes only and are not a substitute for the driver’s judgment of safe parking conditions, including specific road or weather conditions. Do not depend on these alerts to determine whether or not it is safe to park at any location. You are always responsible for parking safely.
 
OP
OP

RickKeen

Well-known member
First Name
Rick
Joined
Sep 14, 2022
Threads
42
Messages
507
Reaction score
649
Location
Minnesota
Vehicles
F150L SR Pro
Occupation
sw engineering manager,
Parking pawls get tested all the time when parked vehicles are dragged onto flatbed tow trucks and trailers using a winch without bothering (or access to the key) to shift the car out of park. The tires just skid before anything gets damaged.

To destroy the parking pawl in the Lightning, I would imagine you would have to engage it while the vehicle is moving at some speed, causing the rotational inertia of the spinning tire, wheel, hubs, rotors, axles / half shafts, and all the spinning internals of the motor/reduction/differential unit to all hit the pawl. Hopefully the software or mechanism is not ever going to let that happen.
 
Last edited:
OP
OP

RickKeen

Well-known member
First Name
Rick
Joined
Sep 14, 2022
Threads
42
Messages
507
Reaction score
649
Location
Minnesota
Vehicles
F150L SR Pro
Occupation
sw engineering manager,
Here is the Munro video where they tear down the Cybertruck motors. I scanned through it quickly and did not see any mention of a parking lock. I would imagine if it had a parking lock, Munro would mention it.

 

Sponsored
OP
OP

RickKeen

Well-known member
First Name
Rick
Joined
Sep 14, 2022
Threads
42
Messages
507
Reaction score
649
Location
Minnesota
Vehicles
F150L SR Pro
Occupation
sw engineering manager,
Here is a video that explains the electric parking brakes similar to what are used on the Lightning (and I would presume similar on the Cybertruck, except perhaps its a 48v motor instead of a 12v motor).


The small electric motor drives a screw that pushes on the brake caliper. There is a gear set with some ratio between the motor and the screw. So the ultimate amount of caliper force it can generate is going to be the stall torque of the motor x the gear ratio x the screw ratio (less the gear and screw friction).
 
Last edited:
OP
OP

RickKeen

Well-known member
First Name
Rick
Joined
Sep 14, 2022
Threads
42
Messages
507
Reaction score
649
Location
Minnesota
Vehicles
F150L SR Pro
Occupation
sw engineering manager,
I was unable to find a spec for the exact EPB in the Ford (or the CT), but the typical force an electric parking brake actuator can generate seems to max out around 25kN for heavier duty units. Which is about 5600 lbs. To make the math simple, assume a 12" brake rotor and a 30" tire and an ideal brake pad coefficient of friction of 1.0. That gets you enough braking torque for 2240 lbs of horizontal rolling force on each rear wheel (4480 total). Which is slightly below the rear axle rating of the truck (4900 lbs). If you load the truck to its max axle weight rating front and back, and park on a steep enough hill, it seems you could theoretically get the parking brake to slip (before you can get the tires to skid). That marginal case is likely why Ford includes the parking pawl.

The original thread in the Cybertuck forum involved heavy boat trailers on boat launch ramps. Note that NO parking brake or parking pawl on just the rear axle of the truck can overcome the fact that a heavy trailer can drag the truck down the hill with its rear tires skidding even if the wheels are locked (especially on a wet, algae-slick boat ramp). Because most of the weight of the trailer is not on the rear axle of the truck, the trailer weight cannot contribute to the traction of the truck rear tires, but still contributes to pulling it down the hill.

ALWAYS chock your trailer when parking on a steep hill.
Always use your most aggressive 4WD mode (diff locked) when launching a boat.
 

Effonefiddy Lightning

Well-known member
First Name
Alfred
Joined
Jun 2, 2022
Threads
2
Messages
259
Reaction score
202
Location
California
Vehicles
23 F150 Lightning SR Antimatter Blue /2023 Model Y
Occupation
Retired
Take a survey. I have yet to hear a single person that doesn't already have one saying "Man, that's a great looking truck".
I'm pretty sure some of the CT owners think so. Some might just like Tesla tech and can get pass its looks. At this point making that comment when its not even the subject matter in this thread is just beating a dead horse with a stick.
And just because you haven't heard anybody say that, it doesn't mean that person doesn't exist.
 

Effonefiddy Lightning

Well-known member
First Name
Alfred
Joined
Jun 2, 2022
Threads
2
Messages
259
Reaction score
202
Location
California
Vehicles
23 F150 Lightning SR Antimatter Blue /2023 Model Y
Occupation
Retired
Maybe it’s me but I find it annoying that Ford can’t set the electronic brake when I put the truck in Park. If I forget or am slow pulling the electronic brake the truck rocks back and forth or rolls forward an inch. It’s sloppy. There are tons of these things. If you haven’t owned a Telsa you don’t know to be annoyed.
I noticed in mine it randomly decides whether or not to do it. Today I also noticed it stayed in drive when I open the door. That was scary.
 

Runaway Tractor

Well-known member
Joined
Jan 25, 2024
Threads
12
Messages
426
Reaction score
657
Location
USA
Vehicles
Yes
Geez. So you must have information that the CT does in fact have a mechanical park lock? If you can prove that it does, then I stand corrected.
That isn't what I said. That isn't even remotely close to what I said. You are making things up. You're now just a disingenuous liar, or too incompetent for this discussion. Not sure which.
 

Sponsored

TaxmanHog

Moderator
Moderator
First Name
Noel
Joined
Jan 19, 2022
Threads
171
Messages
12,334
Reaction score
13,000
Location
SE. Mass.
Vehicles
2022 Lightning Lariat-ER Max Tow & 2024 Harley-Davidson Road Glide CVO-ST
Occupation
Retired
I noticed in mine it randomly decides whether or not to do it. Today I also noticed it stayed in drive when I open the door. That was scary.
Try unbuckling and then open the door, it should auto park the selector.
 

Firn

Well-known member
Joined
Aug 26, 2024
Threads
9
Messages
261
Reaction score
235
Location
USA
Vehicles
23 Pro ER
So you guys think that the CT wouldn't be a safety risk if either the electrical system that powers the park brake fails or the park brake's mechanics themselves failed?
Why are you making up these things we are "claiming" to say? If you want to discuss those items, great, but don't you dare say that is what others are claiming when NOTHING of the sort was said
 

StevenC56

Well-known member
First Name
Steven
Joined
Sep 13, 2024
Threads
3
Messages
141
Reaction score
87
Location
Fresno California
Vehicles
2024 Lightning Lariat Avalanche, 2017 Explorer Platinum
Occupation
Retired
This thread is about the Lightning having a parking pawl and the CT possibly not having one. So, what is it you guys think about this subject then if the CT does in fact have no mechanical parking mechanism?
 

Runaway Tractor

Well-known member
Joined
Jan 25, 2024
Threads
12
Messages
426
Reaction score
657
Location
USA
Vehicles
Yes
This thread is about the Lightning having a parking pawl and the CT possibly not having one. So, what is it you guys think about this subject then if the CT does in fact have no mechanical parking mechanism?
Nobody but you is fabricating that thought, so nobody has an opinion on it.
 
 





Top