Emergency Brake Yes/No

[VirtualJSK]

Some good comments on here, some (presumably ChatGP) nonsense too.

Have a look at this ZF parking pawl.
View attachment 7916406

When you engage park the pawl may drop into one of the slots, or on a flat section.

If you engage park on a hill and the pawl is resting on a flat section the vehicle will roll until the pawl engages. That will eventually wear the pawl or the gear.

Note the pawl on the ZF HP8 is controlled by a solenoid using hydraulics, actually the solenoid disengages the pawl rather than engages it.

Just to be clear...
The primary method of stopping a parked vehicle from moving is the handbrake. For example normally an electronic parking brake is automatically engaged when the vehicle is stopped.

While unlikely to break, replacing a parking pawl and ring will never be cheap.

If a handbrake doesn't work, it needs adjusting or the pads/shoes replacing.

Very helpful photo. Thanks.

 

[Tinerfeño]

Just to be clear...
The primary method of stopping a parked vehicle from moving is the handbrake. For example normally an electronic parking brake is automatically engaged when the vehicle is stopped.

On a level place, like my yard in Finland, I use only Park. Handbrake + Park always if there is any inclination. With manual gearbox I prefer leaving the car in gear, especially during winter to avoid freezing problems on cable or brake shoes.

And concerning wear it is better to use the handbrake regularly because that prevents jamming of the moving parts. It will be anyhow tested in MOT and if unused it may stuck. And the cable doesn't stretch any measurable amount despite daily use. I think I still have the original handbrake cable in my -93 Discovery with 600000 km in odometer.

 

[AWo]

I would always use the normal parking brake. Chances are higher, that the automatic gearbox is not damaged, when a car bumps, even lightly, into you car. The impact may lead to a bend blocking mechanism which needs a repair afterwards. With the parking brakes applied, you may end up with the wheel scratching over the tarmac or they reduce the impact.

AWo

 

[Dokatd]

Some good comments on here, some (presumably ChatGP) nonsense too.

I read most all of this thread again, which posts do you believe are AI?

 

[Glen]

Some good comments on here, some (presumably ChatGP) nonsense too.

Have a look at this ZF parking pawl.
View attachment 7916406

When you engage park the pawl may drop into one of the slots, or on a flat section.

If you engage park on a hill and the pawl is resting on a flat section the vehicle will roll until the pawl engages. That will eventually wear the pawl or the gear.

This is why I find a lot of comments here to be in error. If you apply the parking brake first, there’s some chance the pawl won’t engage. If you want both the pawl and the parking brake to contribute to holding the vehicle stationary, the correct order of ops is to select Park on the transmission, take your foot off the brake and then apply the parking brake. This gives the best chance for the pawl to engage.

Alternately, if you think there’s some chance your vehicle will be towed (you’ve parked in violation of ordinance), leave the transmission in neutral with the handbrake set so when they drag your vehicle out of the parking spot, they aren’t putting an extreme load on the parking pawl. I haven’t tested if this is even possible in the Grenny - turn the ignition off in gear and the transmission automatically selects Park.

All of this seems largely pedantic to me. IMO, loads on the pawl and parking brake ought to always be minimal. Anything more than approximately a 6% slope and I will use a wheel chock or find a big rock to ensure my unattended vehicle stays put.

For manual transmissions parked on extreme slopes, I’ll put the transfer case in low range and leave the transmission in 1st. If I’m pointed uphill, I’ll leave the transmission in reverse since valving allows engines (at least gasoline engines) to easily turn over backwards (the engine would be driven in reverse if gravity pulls the vehicle backwards with the transmission in 1st).

 

[Dokatd]

This is why I find a lot of comments here to be in error. If you apply the parking brake first, there’s some chance the pawl won’t engage. If you want both the pawl and the parking brake to contribute to holding the vehicle stationary, the correct order of ops is to select Park on the transmission, take your foot off the brake and then apply the parking brake. This gives the best chance for the pawl to engage.

Alternately, if you think there’s some chance your vehicle will be towed (you’ve parked in violation of ordinance), leave the transmission in neutral with the handbrake set so when they drag your vehicle out of the parking spot, they aren’t putting an extreme load on the parking pawl.

All of this seems largely pedantic to me. IMO, loads on the pawl and parking brake ought to always be minimal. Anything more than approximately a 6% slope and I will use a wheel chock or find a big rock to ensure my unattended vehicle stays put.

For manual transmissions parked on extreme slopes, I’ll put the transfer case in low range and leave the transmission in 1st. If I’m pointed uphill, I’ll leave the transmission in reverse since valving allows engines (at least gasoline engines) to easily turn over backwards (the engine would be driven in reverse if gravity pulls the vehicle backwards with the transmission in 1st).

Interesting, I just kinda assumed Ignorance in those posts. So many people are taught incorrectly and continue to pass that knowledge along. It's hard to explain to them that they are wrong especially when several people back them up.

I'm not sure how you would gauge 6% but I agree in overall principle.

And parking in gear with a manual is a tough one. Some diesels will start right up if they roll. My Unimog 1300L and 411 are examples of that. Granted all my other diesels have a definitive shut off.

 

[Glen]

I'm not sure how you would gauge 6% but I agree in overall principle.

My driveway has sections graded at 8% and 12% by zoning ordinance (max permitted), so I’ve had thousands of trips to memorize those grades. 6% is just 6 ft rise in 100 ft forward (or meters or any other measure) so an easy thing to judge in my experience . . . not that I measure anything before using a chock.

 

[Dokatd]

My driveway has sections graded at 8% and 12% by zoning ordinance (max permitted), so I’ve had thousands of trips to memorize those grades. 6% is just 6 ft rise in 100 ft forward (or meters or any other measure) so an easy thing to judge in my experience . . . not that I measure anything before using a chock.

Gotcha, I was thinking 6% load which is why I felt that standard to be dubious but admirable. Now I gotcha on slope gradient and that makes more sense now.

 

[JHIG1]

Every time for me

 

[skinny_tom]

Thanks for whoever posted the picture. I've been in a few transmissions. No way I'm leaving my car's stability to a mechanism that fails open. The entire mechanism is designed to open if there's a failure in the system. And, if you look closely at the pawl itself, it is designed to not "lock" in place so that it can release when there's pressure on it. If it's not fully engaged or the mechanism to hold the pawl in place is weak or fails...

Also, as mentioned, good habits die hard. Train yourself to properly engage the parking brake every time you park the car and you won't forget the one time that it really matters- probably in some super stressful situation where being 100% sure the car won't move prevents a life-or-death situation. Or even just the loss of your vehicle situation.

How many people let their pick-up trucks back themselves down the boat ramp to become a submarine because they've trained themselves to ignore the parking brake?

I bet each and every one of them said "I only use the parking brake when it's needed" and then don't. Old habits die hard.

 

[Dokatd]

How about a little real world data. Out of curiosity I went and set my truck up on this little hill on my property.

• Hand brake only with moderate pull of handle. Not a strong man pull as I am larger than most people.

In Neutral the truck easily rolled back down the hill and lurched to a stop.

• Transmission in park only

Truck moved slightly as I gently let off foot brake and transmission pawl engaged. Truck stayed solid and I was able to get out and take this pick. Great news is that shifting back into drive was pretty uneventful with only a slight objection by the pawl as it unlocked.

Long story short, use both if in doubt. But the transmission parking pawl is way more positive than the hand brake is and is not reliant on the user pulling hard enough.

For context this is an approximate 30 degree incline

Now get out from behind your keyboard and go try it for yourself and tell me I am wrong.

 

[Krabby]

Is the handbrake on the IG on the rear brakes or drive shaft? On Series LRs it was on the driveshaft.

 

[Dokatd]

Is the handbrake on the IG on the rear brakes or drive shaft? On Series LRs it was on the driveshaft.

Rear calipers only on the IG.

So the parking pawl has a significant gear reduction advantage over the back calipers.

 

[skinny_tom]

View attachment 7916414

How about a little real world data. Out of curiosity I went and set my truck up on this little hill on my property.

• Hand brake only with moderate pull of handle. Not a strong man pull as I am larger than most people.

In Neutral the truck easily rolled back down the hill and lurched to a stop.

• Transmission in park only

Truck moved slightly as I gently let off foot brake and transmission pawl engaged. Truck stayed solid and I was able to get out and take this pick. Great news is that shifting back into drive was pretty uneventful with only a slight objection by the pawl as it unlocked.

Long story short, use both if in doubt. But the transmission parking pawl is way more positive than the hand brake is and is not reliant on the user pulling hard enough.

For context this is an approximate 30 degree incline

Now get out from behind your keyboard and go try it for yourself and tell me I am wrong.

What does this prove? That it held the one time you used it?

Use them both. It's why they exist and are legally required.

 

[landmannnn]

On a side note, there are kits around to add a manual pawl unlock for the ZF HP8.

Would they work on the IG?

https://www.seemslegitgarage.com/product-page/bmw-park-lock-kit?srsltid=AfmBOoqsrUEFHplyu2dmpJXc8SWXVW6JnfGfwxQGVPmPVEtlGGSSK0Cq

 

[Dokatd]

What does this prove? That it held the one time you used it?

Use them both. It's why they exist and are legally required.

What it proves is that park is a positive condition regardless of who engages it and parking brakes are not. There are more variables to hand brakes than the park position on your transmission.

If you were to use one or the other you should default to park. But that's moot with the IG as it automatically goes to park when you shut down.

Hand brakes are legally required in the USA to be installed but not used. Some states may differ though.

Ultimately the point is use what you like, but the park position is more positive than the hand brake period. It's also more reliable. Telling someone they are categorically wrong for using just the transmission parking brake is ignorant at best.

Are we not allowed to prove our point on this forum? Why is it bad for me to express my opinion and back it up with some simple real world data. Just because 10 people dog pile me doesn't make those 10 people right, nor does my victim hood make me right or wrong.

 

[landmannnn]

Are we not allowed to prove our point on this forum? Why is it bad for me to express my opinion and back it up with some simple real world data. Just because 10 people dog pile me doesn't make those 10 people right, nor does my victim hood make me right or wrong.

Of course you are allowed to express your opinion, especially in the form of a rational argument.

Telling someone they are categorically wrong for using just the transmission parking brake is ignorant at best.

However such overt criticism of somebody expressing an opinion (which may or may not be wrong) hardly suggests you are a victim.

 

[Logsplitter]

Is the handbrake on the IG on the rear brakes or drive shaft? On Series LRs it was on the driveshaft.

Post 40 above has an explanation of the handbrake setup

 

[Dokatd]

However such overt criticism of somebody expressing an opinion (which may or may not be wrong) hardly suggests you are a victim.

I am nowhere near a Victim, I was being sarcastic.

 

[landmannnn]

I am nowhere near a Victim, I was being sarcastic.

Sorry, missed that!