Does applying the parking brake help with transmission life?

brakes
transmissions

#1

My friend insists that when I drive his '97 Dodge Ram van I apply the emergency/parking brake before letting my foot off the brake when putting the van in Park. He says that it significantly reduces wear on the transmission because the vehicle weight sits on the parking brake and not on the gears. This seems plausible, but I’ve never heard this from anyone else before. Is this true? And if so, how much does it really save on transmission wear and tear?




#2

The output shaft of the transmission has a gear meshed to it. When you put the transmission in park a lever called a parking pawl engages this gear. This pawl keeps the gear, and therefore the output shaft from turning. The gear performs no other function. Does it cause wear? Sure. But that’s what it’s for. If you wore it out completely the “park” function wouldn’t work, everything else would still work normally.

Automatic transmissions do not wear gears out. They wear internal clutches and bands out. They wear seals out, which cause internal hydraulic leaks, which result in worn clutches and bands.

Having said that, it’s his truck, so it’s his rules. Use his parking brake. When he drives your truck (or car) it’s your rules. Tell him he’s not allowed to make left turns because it wears the steering wheel out.


#3

Your friend is giving you good advice. While it is not all that important if you always park on level ground, it is still important.

The transmission’s parking pawl is really a backup device, not a substitute for the parking brake.

Consider the cost of repairing a parking pawl and repairing a parking brake and I am sure you will want to use that parking brake as your primary.

Also consider that if you fail to use the parking brake they tend to collect rust and then fail. 

My friend insists that when I drive his '97 Dodge Ram van I apply the emergency/parking brake before letting my foot off the brake when putting the van in Park.

It's his car, even if he were wrong (he's not) you still should follow his instructions when driving his car.

#4

I always follow the procedure your friend outlined when I park either of my vehicles, one automatic, the other manual. The transmission is designed to make the vehicle go. The parking brake is designed to hold it in place.

Who wants the entire weight of a vehicle resting on one little 1/2 inch pin? Not me.


#5

Consider that if you park your car without using the parking brake and the parking pawl fails, you can be successfully sued for negligence for any resulting injuries and damage because you ignored the instructions in your owner’s manual.


#6

I didn’t give this advice much thought until I had a transmission apart and saw how the parking pawl actually worked.

Your friend is giving you very good advice.


#7

That is what required liability car insurance covers in the very rare case it actually happens.


#8

An additional benefit is that this helps keep the parking/emergency brake working correctly.


#9

And in some vehicles this is what adjusts the rear brakes.


#10

I would never consider having insurance to mean that it is okay to be neglectful. Also, having insurance doesn’t remove your liability. If your victim decides that the possible max insurance settlement is not enough, they can still sue you. (In practice, most go for the insurance, since that is where the most money usually is.)


#11

Alright Scottoblotto,

Now lets hear from you about the recommendations you just got. (Aside from the insurance remarks, I mean)

Just like a clutch and brake pedal, the PARKING BRAKE is installed by the vehicle manufacturer for a very good reason…to be used. In this case, consistently.


#12

I understand all the reasons why this is good advice, but how many people have seen transmissions where the parking pawl has failed?


#13

how many people have seen transmissions where the parking pawl has failed?

We seem to see one about every month or two.


#14

I use my parking brake on my Civic when I park it. But, since it’s been getting well below freezing quite often, I don’t usually engage it when I park it. I’d rather put a little extra wear on the prawl than deal with a frozen parking brake that’s dragging one of my rear brakes.


#15

And what if you don’t set the parking brake and someone gets killed as a result?


#16

It depends where the parking pawl is located. I have never cared about this before but it would make sense to have the pawl where the gears aren’t involved at all.

Furthermore, The transmission is in neutral when you put it in park so I know that your friend has made up a story. If an urban legend isn’t well known, does that make it a suburban legend?

Saving the parking pawl is a good thing to do. Some older vehicles will roll into things if the thing fails or is so worn that it just slips out.

If he insists that the brake be set first, he’s doing very well and following what is or should be in the owner’s manual. Sometimes it’s the people who don’t really know all the reasons why who end up doing things right.

No wonder I can’t stand them!


#17

I’m surprised this got so much attention. I was waiting to see if there was any kind of consensus.

Whole insurance discussion was not what I was interested in.

My car is manual, so whenever I park it I always put the parking brake on. Even when I drive someone else’s automatic I usually put the parking brake on. (Although at one point in my youth I remember when I owned an automatic I stopped putting the parking brake on because numerous times I would then forget to disengage it, thus eventually rendering it useless.)

I do now feel more educated in how the Park gear/position works with the pawl. So thanks for explaining that.

But I suppose the crux of the question is now: does the order in which you engage the parking brake and the Park gear have a significant affect on stress to the parking pawl? Maybe just on hills?


#18

When someone turned in a claim for trans damage the insurance company that would hire me to inspect ALWAYS stated that, if the parking pawl is sheared (from not using the park brake and playing transmission basketball,bounce,bounce) it was not covered AND the teardown and reassembly fee was to be paid by the owner.

park brakes are a good thing.


#19

Well, I guess I ought to clarify my original post.

It’s not a bad idea to use a parking brake. It is a bad idea to depend on the parking brake or a parking pawl or any other single means to restrain 3 or 4 thousand pounds of unattended car on a hill. It’s usually a legal requirement, while parked on a hill, to turn the front wheels into a curb to use the curb to restrain the car in the event of a mechanical failure.

If you’re parked on level ground, almost anything will keep the car from moving. There’s virtually no wear or pressure on the parking brake or pawl.

As for wearing them out, it’s rare. I’ve seen exactly one pawl slip on a hill, so it does indeed happen. I’ve also seen on other pawl overcome, by someone totally unfamiliar with driving an automatic equipped car, and she didn’t take it out of park, while she rev’d the engine and 5 or 6 equally unfamiliar burly teenagers pushed the car from behind. They were able to move the car a few feet at a time, only for it to stop as soon as they stopped.

I rarely use my parking brake, I prefer by far to use the curb as a safety to make sure the car won’t move, because I’ve never seen any parking brake that would hold a car securely, especially from rolling backwards.

But I’ll say it again: his truck, his rules. Use the parking brake in his truck, do whatever you like in your own.


#20

The best practice is (hills or not) to (1) apply and hold the main brake, (2) shift into part, (3) apply parking brake, and (4) release main brake.

Note: The main reason to shift to park before applying the parking brake is that some cars have auto-release on the parking brake and will not let you lock it on until the transmission is in neutral or park.