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I've noticed if im on an incline, when I shift to forward or reverse-its very rough. Note the incline doesnt have to be steep to happen. When its level, the shift is smooth. Anyone else experience this? (I have an appt. scheduled).
 

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My father has a pretty steep inclined driveway. When I'm parked in it, and I put my Ascent in reverse, I absolutely know what you are talking about.

I'll be curious about what they tell you at your appointment.
 

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Are you folks using the parking brake? Are you disengaging the parking brake with your foot on the brake pedal? If not, then you are loading the transmission against the parking prawl and it takes some effort to disengage the prawl with the load of the car on it.
 

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Discussion Starter · #4 ·
No parking brake, the inclines are pretty mild. I'll try it though!
 

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No parking brake, the inclines are pretty mild. I'll try it though!
It's that, I'll tell you. If it's a Subaru that is, I use my parking brake every time I park the car. I need to set my parking brake in the parking of my grocery store, it essentially flat except for pitch-drainage. My cars still have the hand-e-brake style so its an easy motion.

But think about it, if the car was in neutral and not park, would it roll? If it would roll at all, the prawl is being loaded and it will be both harder to pull out, and it will make more noise and the car may roll to the position now caught by the brake pedal. It's more of a Subaru thing than with other brands. For example my solid axle Chevy trucks, my Ram or my Jeep Cherokee XJ would only need it on steeper inclines. The Jeep had a hand brake I would set every time. The trucks had the pedal and a release. They would get set less often.

I think I would literally lose my mind if I was forced to drive a car with the electronic silliness. (button)
 

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It's that, I'll tell you. If it's a Subaru that is, I use my parking brake every time I park the car. I need to set my parking brake in the parking of my grocery store, it essentially flat except for pitch-drainage. My cars still have the hand-e-brake style so its an easy motion.

But think about it, if the car was in neutral and not park, would it roll? If it would roll at all, the prawl is being loaded and it will be both harder to pull out, and it will make more noise and the car may roll to the position now caught by the brake pedal. It's more of a Subaru thing than with other brands. For example my solid axle Chevy trucks, my Ram or my Jeep Cherokee XJ would only need it on steeper inclines. The Jeep had a hand brake I would set every time. The trucks had the pedal and a release. They would get set less often.

I think I would literally lose my mind if I was forced to drive a car with the electronic silliness. (button)

Same here. I use my parking brakes every time I park the car now, after experiencing a rough shift (and more than usual roll) when parking the car if the brakes are not used. Prior, when I shift from Park to Reverse, not only is it a rough shift where you have to force the lever done, it makes this heart dropping grinding noise. With the parking brakes on, it's all smooth and calm. This is something I'm adding to the list for the dealership to look at when I take my car in for maintenance.
 

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Any update on this? I have the same issue. My 2018 loaner Outback doesn't do it nearly as badly. I am starting to stack the issues up for the next service (it's already in for service now). Good grief...
 

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There’s nothing to update. It’s how the parking system is designed. My Forester has done the same thing since the day I’ve owned it.
 

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I also use mine and waiting for day when the parking brake fails to disengage. I wonder how durable these motors are.
 

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The EPB on my Outback was still going strong after 6 years and multiple cycles daily. I think it's fairly robust and nothing to really anticipate crapping out one day.

I'm surprised it hasn't been mentioned yet, but to get the smoothest shift out of park, the best way to do it is to shift into neutral when applying the parking brake. Then put it in park. No more *clunk*.
 

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The EPB on my Outback was still going strong after 6 years and multiple cycles daily. I think it's fairly robust and nothing to really anticipate crapping out one day.

I'm surprised it hasn't been mentioned yet, but to get the smoothest shift out of park, the best way to do it is to shift into neutral when applying the parking brake. Then put it in park. No more *clunk*.
I think it shouldn't be necessary to use the parking brake to offload the parking pawl in the transmission -- that's what the parking pawl is meant to do!! I used to park my 6000lb GMC Sierra on my driveway each day, without the parking brake (just using the transmission's park gear) and it would smoothly move out of park into drive, no complaints, nothing rough or weird. This is true for other vehicles I have owned, but not the Ascent. It feels like something's going to break and it shudders the whole car when you pull it out of park into drive while on even a moderate incline.
 

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Absolutely always set the parking brake on almost every car, b4 taking foot off brake

I think it shouldn't be necessary to use the parking brake to offload the parking pawl in the transmission -- that's what the parking pawl is meant to do!!
It's actually not supposed to be used on any sort of incline in virtually any car in the US market. The parking brake is supposed to be used on any incline on virtually any car. That's been the recommendation since parking brakes became a mandatory thing decades ago.

As a matter of fact, the standard recommendation for any parking use, for almost any car in this country, is to apply the parking brake before letting go of the brake pedal or before engaging the parking pawl on the transmission.

There are two key standards related to the parking pawl:
  • FMVSS 114 – Theft Protection and Rollaway Prevention, Keyless Ignition Systems
  • SAE J2208 – Park Standard for Automatic Transmissions

Most vehicle manufacturers (for instance this) and auto mechanics (for instance, this expert) do not recommend using the transmission's parking pawl as the sole means of securing a parked vehicle, instead recommending it should only be engaged after first applying the vehicle's parking brake.

That's been the SAE standard, and the NHTSA requirements/suggestions for many years (decades)

Here's some boring standards reading:

GM has recommended parking brake use for decades:
That's also GMC's recommendation for the Sierra and every car they've built for decades, for the exact same reasons. 2018 Sierra Manual: pg 262, 263, 281 (link)

Torque Lock
If you are parking on a hill and you do not shift the transmission into P (Park) properly, the weight of the vehicle may put too much force on the parking pawl in the transmission. You may find it difficult to pull the shift lever out of P (Park). This is called torque lock. To prevent torque lock, set the parking brake and then shift into P (Park) properly before you leave the driver seat.
Alas, that's literally part of the standards and regulations. There used to be a ton of problems with parking pawls snapping and cars rampaging down hills. Thus, parking brakes, and instructions in virtually every vehicle manual to use them, became a required thing.
 

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Ow! Ow! You're hitting me with facts. STOP IT! :)

I suppose I am guessing most people don't apply the parking brake to their vehicle prior to putting them in park, especially on their driveways (if they aren't very steep, like mine). It is true that I have experienced a form of torque lock in other vehicles I have owned, even on this very driveway, but the releasing of that torque didn't seem as violent as on my Ascent. This falls into one of those cases where engineers should design the product to fit the usage patterns of their customers, not force their customers to use their designs differently.

I want to add: you mentioned the United States specifically. Does that imply other countries have different standards?

So the question becomes: how much damage will torque lock cause to the Ascent transmission and drive train over the long run? It's going to happen to someone, somewhere.
 

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I want to add: you mentioned the United States specifically. Does that imply other countries have different standards?
Other standards, but not necessarily completely different. I haven't compared, so I don't know what the differences are for parking related systems.

So the question becomes: how much damage will torque lock cause to the Ascent transmission and drive train over the long run? It's going to happen to someone, somewhere.
It's a beefy parking pawl. Probably the same as any other vehicle. It's also designed to meet the newest requirements. I kinda suspect newer ones are more susceptible to torque lock because of the newer requirements to help prevent roll-aways and thefts, but I can't access all of the SAE standards to see what's changed. In the NHTSA docs, you can see the requirements for the pawl (which, btw, are for limited incline and limited force, even in the newest requirements).

That it grabs well isn't a sign of it going to fail in the future. It means the design doesn't have as steep of a slip-away edge, so that it grabs better.

This gives you an idea of how tiny the grab arm is on parking pawls.



This doesn't happen very often anymore:


Here's a "deeper" one


vs one that is more tapered and doesn't engage as sharply from a BMW M3


As you may be guessing, the ones that are best capable of holding a car are the ones that are less tapered and more likely to bind. It doesn't mean they're more likely to break or accidentally release (when they shouldn't).
 

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I want to add: you mentioned the United States specifically. Does that imply other countries have different standards?
Unrelated to parking pawls and the issue where it's been recommended for years that you use a parking brake ...

Yes, other countries have other standards.

That's why an Outback has a towing capacity in the U.S. of 2,700 pounds, while the SAME car in England has a towing capacity of 4,400 pounds.

The car is the same (other than which side the driver sits on), but ...

In the U.S., you can tow a car down an interstate highway at 75 mph if that's the speed limit, while in England "Towing units are limited to 50 mph on rural single carriageway roads and 60 mph on dual carriageways and motorways, provided there aren't any local or temporary lower limits in force. "
 

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I find flat landers are the worst offenders to improper parking brake use. It never really mattered to them. When we get economic booms in the Bay Area the number of roll away hill parked cars becomes a nearly daily event. The same people are shocked that in SF they write tickets $100 a pop for not properly curbing tires on hill parking. Yes its that common to see driverless cars barreling down streets here when we get lots of flat landers moving into town.
 

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Other standards, but not necessarily completely different. I haven't compared, so I don't know what the differences are for parking related systems.



It's a beefy parking pawl. Probably the same as any other vehicle. It's also designed to meet the newest requirements. I kinda suspect newer ones are more susceptible to torque lock because of the newer requirements to help prevent roll-aways and thefts, but I can't access all of the SAE standards to see what's changed. In the NHTSA docs, you can see the requirements for the pawl (which, btw, are for limited incline and limited force, even in the newest requirements).

That it grabs well isn't a sign of it going to fail in the future. It means the design doesn't have as steep of a slip-away edge, so that it grabs better.
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As you may be guessing, the ones that are best capable of holding a car are the ones that are less tapered and more likely to bind. It doesn't mean they're more likely to break or accidentally release (when they shouldn't).
But this doesn't explain why the 2018 Outback I have performs the transition from Park to Drive much more smoothly than the Ascent on the same driveway and incline. Sure, different design, but if the end result is a more abrupt transition, that seems like something that should have been paid more attention to.
 

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Different weight, different CVT, different requirements...

But this doesn't explain why the 2018 Outback I have performs the transition from Park to Drive much more smoothly than the Ascent on the same driveway and incline. Sure, different design, but if the end result is a more abrupt transition, that seems like something that should have been paid more attention to.
There's a few reasons:

  • The Ascent is a 2019 vehicle - the model year determines the requirements, not when it's built.
  • The Ascent has a new high torque CVT. The Outback loaners are generally 2.5L with regular CVT.
  • The Ascent weighs a lot more (1,150 pound GVWR difference at the least) and requires a parking pawl that engages to hold that far greater weight. You'll note in the NHTSA link above that weight plays a factor in the requirements.
 

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There's a few reasons:

  • The Ascent is a 2019 vehicle - the model year determines the requirements, not when it's built.
  • The Ascent has a new high torque CVT. The Outback loaners are generally 2.5L with regular CVT.
  • The Ascent weighs a lot more (1,150 pound GVWR difference at the least) and requires a parking pawl that engages to hold that far greater weight. You'll note in the NHTSA link above that weight plays a factor in the requirements.
  • So if I tried this with a 2019 Forester I could expect a similar behavior?
  • Forgive me, I don't see 277-ft lbs as "high torque" when we live in an era with factory 400+ HP and torque Mustang GTs flying out of the showrooms. It's a matter of perspective, I suppose. :grin:
  • I do agree that since the Ascent is a heavier vehicle, which is one of the reasons I preferred it to the Outback and Forester, that does mean parts inside the transmission would need to be scaled up to accommodate that increased weight. It just seems like this could have been done smoother.

I have started to adjust my parking procedure to accommodate this...oversight...but invariably I will forget to apply the parking brake on an incline and be reminded of this issue when I try to put the Ascent in drive, assuming I even keep this vehicle for much longer.
 
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