VisualEchos

iTrader: (1)

Man, doing searches for this one gave me the phone book big-time.

2007 Acura TL, base w/NAVI, 83,000 pampered miles.

Simple issue. When I'm parked on a hill, and put my car into drive, there is a slight pause, and when the car goes into gear I hear a click/chunk sound. It's not BAD, or super loud, but obvious. The trans seems fine in every other way, I'm just wondering what this sound could be. I have replaced the side motor mount, just wondering if it could be one of the other mounts. I plan to do the front, and the top trans mount very soon.

Ideas?

polish_pat

No worries as long as you change your habits soon enough.

That clunk you hear is a sort of fork inside the transmission that goes up when put in P or R. When on a hill, and when you have bad habits, put your foot on the break, put in park, turn off engine, release brake and let the gear friction of the transmission prevent your car from rolling down the hill. What that does is the fork has to force itself in place when you want to go in gear, thus making that clunking sound.

The best way to go about is to park the car, put on the brakes, crank the handbrake to a good tightness and then put in P. Like that you let the friction of the brakes do the work and if ever that hill is too steep for the handbrake alone, the transmission will act as a backup break. Even if you keep those bad habits, it should not do any serious damage on the short term, and unless you live in San Francisco, it will happen so rarely to park on a hill that it should be nothing to worry about.

VisualEchos

iTrader: (1)

Sounds plausible. I'm wondering though, I don't recall reading this technique in the manual. Do you think it's detrimental to the car to do it the normal way?

01acls

Humor you... Hill parking 101. When parking on a hill you suppose to let the tire rest on the curb. Taking all weight off of the trans and then set the parking brake. Eliminating your problem.

LoneRonin

WTF?? Where do they teach this?

Will Y.

Setting the parking brake before shifting an auto trans into "P" minimizes the wear and pressure on the parking pawl. There are instances of broken parking pawls, although it's not common.
I set the parking brake first just to avoid that possibility, and it's the same process as parking a manual trans car on hills anyway.

And yes, the noise on shifting into "D" while parked on a hill could also be a mount.

Maybe in San Francisco.
I've seen people do that while parked on hills there, but I prefer to use the parking brake rather than rest the tire against the curb.

ulrblitzer

Driver's Ed in the early 2000's for me. I remember cranking the wheel so the car rolls into the curb when parking on hills instead of solely relying on the e-brake or tranny.

I do it to this day, driving a manual.

01acls

Its a safety thing, incase ebrake fails so car does not roll off and hit something or hurt someone.

VisualEchos

iTrader: (1)

I think when I used the word "hill" I gave you guys the wrong impression. This happens in my driveway, which has just a slight grade.

The Hood by Andrew Thompson, on Flickr

LoneRonin

that's an awesome sky in the background...

If you do this wheel to the curb thing isn't there a risk of damaging for wheels or the bottom of your front bumper especially if you have a skirt??

polish_pat

You eliminate one problem and will probably cause a few more to your rims. Also, it takes one hell of an incline for the handbrake not to be strong enough to keep the car static.

Probably only in SF you need to rest your tires on the curb.

01acls

I don't see what the big deal is? This is basic hill parking proper procedure. You pull up to the curb. Whether it's backed in or driving straight in at an angle. Once you are parallel to the curb then just turn the wheel full lock toward the curb and let the car slowly rest on the curb by feathering the brakes. In most cases the curb is lower than the car's ground clearance, so damage is not an issue.

If the curb is tall then you need to be careful or just turn the wheel and set the p brake but not touch the curb.

Resting on it will not damage the wheel. A hard impact will damage a wheel not constant pressure.

One can damage a wheel by simply scraping a tall curb.

If your car is lowered thats a different story.

Ok enough already... op needs help. Lets stay on topic.

polish_pat

OP already got his answer on the 2nd post. He also got a useful parking lesson.

01acls

polobunny

AFAIK in Canada driver ed they also tell you to orient your wheels towards the curb (AKA curbing the wheels).
Car gets hit, parking brake fails + parking pawl and your car doesn't roll and kill someone as it likely doesn't go up the curb. As 01acls said, basic hill parking procedure.

Many government sectors have a parking procedure that includes curbing the wheels, handbrake on, in gear for manual and even chock the wheels when the vehicle is left unattended.

VisualEchos

iTrader: (1)

Is no one reading my responses?

1. Neither my driveway or where I park at work has a curb.
2. Neither is enough of an incline to use a curb anyway.
3. I don't see anything the manual about using the hand-brake every time I park on a slight grade.

My question was if I was possibly causing damage to the car, as in it won't last 300,000 miles if I do this, by not using the hand-brake.

I thank Pat specifically for explaining what is happening, but would really like something visual. Does anyone have a diagram of what is happening with these parts?

01acls

It's a commonsense thing. Either use the E brake first or stay the course.

It's certainly not good for the car... shift cable/linkages and what ever part thats hanging up or draging.

Will Y.

Google "parking pawl" or "broken parking pawl" to see examples inside the transmission.
I think there was 1 3G TL member that had a broken parking pawl, so it seems pretty rare.

VisualEchos

iTrader: (1)

Got it. So it's the pawl. What a weird word. Lots of pix on google, than you Will.

polobunny

The pawl can take a pretty good beating and usually unless you slam it in park or get bumped by another car when parked it's rare to see a broken parking pawl. Personally I would not worry about the noise even if you heard it every time you park. They're quite strong.

On another related note, you surely have noticed how the car ends up rolling a bit backwards while putting it on park? That's the gap closing until the parking pawl is engaged.

Regarding your previous comment, #2 more specifically mentioning neither is an incline enough to use the curb... your driveway is more than enough of an incline to use a curb. Any incline is enough to use a curb. If it rolls on its own when in neutral, then that cuts it really. Heck, why put an automatic car in park if you're on flat ground? You could well leave it in neutral, but that's obviously a safety problem.

polish_pat

So when the transmission has all the weight of the car in its gears, this, when it moves up and down, will create a lot of friction and will have to force itself in or out of the parking gear, creating that unpleasant noise.

VisualEchos

iTrader: (1)

After parking I don't notice much movement from the car at all, certainly no large movement. Sometimes this noise is more faint than other times as well. If the car has sat for just a few minutes the noise is very faint. If it has sat for hours it's much more pronounced. You guys have made me think about it a bit more, thank you.

polish_pat

Seems to me like the parking pawl again, as the metal expands and contracts due to temperature changes, i guess it reacts differently. One thing is for sure, if you park on a flat surface and use parking brake before switching into P, and it does that noise when you use the car again, you might have a problem.

VisualEchos

iTrader: (1)

Just confirmed that parking on a flat surface, no parking brake, engage park, and get the clunk sound. It's not like a thud, but like a "chink", and there is a little movement from the car. It's just like you think it'd be. And maybe I'm making something out of nothing, I'm just wondering if I should be hearing anything at all when the trans grabs before I let off the brake.

01acls

One thing you can check is the shift cable. Make sure it's adjusted as per service manual. Meaning it's centered in the gear position selected. Ie. so it's not in simi Park position when in Park but, actually centered in the Park position (cable wise).

VisualEchos

iTrader: (1)

It's definitely the pawl, just have to get used to using the e-brake every time I park on a grade, which is a good habit anyway. Thanks Pat/Will/Polo.