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Use Parking Brake with PDK?

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Old 12-29-2012, 11:06 PM
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Rfong
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Default Use Parking Brake with PDK?

In the old days, an automatic transmission could be put into "P" (Park) and it made the parking brake redundant. Even in hilly San Francisco, I can't remember the last runaway car. That includes some of the 15 million tourists who have never seen a hill, let alone parked on one, and had to curb the wheels. They just shove that rental car into "P" and the car is still there when they return.

Of course a car with manual transmission required using the Parking Brake except for those who chose to put the car in gear opposite to the direction of roll. But that always reminded me of clenching your teeth at night.

Now with the dual clutch PDK, is it essential to use the Parking Brake. Or just use it when parked on hills for belt and suspender double protection?

What do you do?
Old 12-29-2012, 11:44 PM
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simsgw
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Originally Posted by Rfong
In the old days, an automatic transmission could be put into "P" (Park) and it made the parking brake redundant. Even in hilly San Francisco, I can't remember the last runaway car. That includes some of the 15 million tourists who have never seen a hill, let alone parked on one, and had to curb the wheels. They just shove that rental car into "P" and the car is still there when they return.

Of course a car with manual transmission required using the Parking Brake except for those who chose to put the car in gear opposite to the direction of roll. But that always reminded me of clenching your teeth at night.

Now with the dual clutch PDK, is it essential to use the Parking Brake. Or just use it when parked on hills for belt and suspender double protection?

What do you do?
I have to admit that I rarely use the parking brake, but I do think of it on hills. I parked in Berkeley a few weeks ago and used the wheel canted to curb method, the transmission in park, the parking brake, and considered throwing out an anchor to the uphill side. Turned out I left the Danforth in the garage at home, but everything turned out okay.

I remember the days when the 'park' setting in an automatic transmission was mostly a throwback to manual transmission days. A pawl engaged a gear on the driveshaft...[?] well, one of the shafts anyway. That pawl could be rounded off with wear and tear, and could pop out of engagement. Darned if I know how they do it with a PDK, but I'll bet two things. No, three:
  • It isn't one percent as likely to "pop out" as the original automatics;
  • Manufacturers will be telling us to use the parking brake also long after automatic Danforth deployment systems are standard;
  • I never will feel comfortable in Berkeley without a parking brake engaged.
Gary
Old 12-30-2012, 02:09 AM
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Mike in CA
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Originally Posted by simsgw
I remember the days when the 'park' setting in an automatic transmission was mostly a throwback to manual transmission days. A pawl engaged a gear on the driveshaft...[?] well, one of the shafts anyway. That pawl could be rounded off with wear and tear, and could pop out of engagement. Darned if I know how they do it with a PDK......
They do it like this......

Parking lock
Even if the vehicle is in gear, it cannot be prevented from rolling back in the same way as on a manual transmission because the clutches are opened in a depressurized state and therefore do not stop the vehicle from moving. The parking lock prevents the vehicle from rolling away, as with an automatic transmission.

When the vehicle is stationary, the parking lock is engaged (purely mechanically) using the selector lever and blocks the pinion shaft via a catch, which engages in the toothing of the parking-lock gear. The final drive is blocked in this way.

Image left: 1. Selector shaft 2. Parking lock gear 3. Catch
Image right: 1. Detent spring 2. Selector shaft 3. Detent disk 4. Connecting rod 5. Catch 6. Leg spring 7. Parking lock gear
Attached Images   

Last edited by Mike in CA; 12-30-2012 at 02:26 AM.
Old 12-30-2012, 09:17 AM
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chuckbdc
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Thanks for that diagram. Now that I know what is going on with all that "machine shop" sound when engaging and disengaging it, I may start doing it more!
Old 12-30-2012, 12:03 PM
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I'mAllIn
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I always use the Park Brake. I'm probably a little old fashioned, but I prefer the "load" to be on the brakes than the gears, or park paw, in the tranny. I do this on all my vehicles and even on flat ground.
Old 12-30-2012, 12:16 PM
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simsgw
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Originally Posted by Mike in CA
They do it like this......
Basically, the same technique automatics always have used. Makes sense, but I'll bet the guys at Stuttgart put a little extra thought into that traditional problem of pop-out.

Gary
Old 12-30-2012, 01:26 PM
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certified_prime
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I just wish it automatically engaged the parking break when turning off the car. I've got a manual, and that would be a nice feature. Especially if the setting could be toggled via the PCM.
Old 12-30-2012, 01:37 PM
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KINGSRULE
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Originally Posted by I'mAllIn
I always use the Park Brake. I'm probably a little old fashioned, but I prefer the "load" to be on the brakes than the gears, or park paw, in the tranny. I do this on all my vehicles and even on flat ground.
+1
Old 12-30-2012, 06:43 PM
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holminator
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I'd use the parking brake, but that's the hand I hold my beer in so I guess I don't use/don't need the e-brake. No offense to the good people that do use it.



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