2012 G37xS Coupe (AWD)


While my car was on jack stands at all four corners, I had my wife shift through the gears from parking, to reverse, to neutral, to drive and then back to neutral, to reverse and then to park. I was doing this to find out where a ticking noise was coming from since I recently ran over a cinder block while on the high way.

Before each transition from R --> N --> D --> N --> R, brakes were applied ensuring that all wheels stop spinning before changing gears. However, during the last gear change going from R --> P, my wife forgot to hit the brakes and shifted directly from "Reverse" to "Park". Since my wheels were off the ground, it was free spinning at the time (acceleration was added during this time). When she shifted from reverse to park without braking to stop the wheels, I heard a grinding noise. I am not sure if this grinding noise is from the transmission, front differential (transfer case) or the rear differential.

How bad is this? This is the first time such an event occurred and as upset as I am with my wife, it was unintentional.

I do plan on getting the transmission flushed in May and both the front and rear differential fluid changed out in May as well.

My G drove fine and shifted through the gears without any discernable issues after I took it out for a 50-mile test drive both in the manual and automatic setting. Should I be concerned? Had my wife completely damaged some of the gears in the transmission, transfer case or rear differential?

 

No gears were damaged in the making of this film. You heard the parking pawl grinding over the detents around the outside of one of the planetary gear cases in the transmission. It's very possible it was damaged, maybe enough that you can no longer rely on it. Use your parking brake every time you park until you can have it checked.

 

Thank you Slartibartfast.

Is there any way I can check if the parking pawl was damaged without taking it to the mechanic? I probably won't have time to stop by at a mechanic until late next week.

Also, is the parking pawl something that can be replaced easily should it be damaged? Is replacing the parking pawl a big and time-consuming job?

Lastly, what is a ballpark price for such a repair?

On a good note, my wife felt so terrible about this, she gave me her blessing to get new wheels.....so that is coming up in May as well.

 

This part is inside the transmission.. Deduce from there.

Park on an incline you'd typically park. Put the car in park and slowly release the brake. Does the car roll back?

If it does, then by all means use the parking brake as recommended above. Repair cost... trans replacement as few places 'fix'/rebuild transmissions these days.

 

Thank you Jsolo.

So in my parking structure, the inclines are at an angle between 25-35 degrees. I shifted my car to park when going down the incline. Did this a few times and no, my G did not roll forward down the incline. Then, I went up the same inclines and shifted to park. My G did not roll back down the inclines (also did this a few times).

Is it safe to believe that the parking pawl is not damaged?

Thanks once again.

 

Based on this it seems to be working. Personally, I'm still in the habit of using the parking brake in our other car, an automatic, every time. It keeps the cable from rusting in place and provides minimal stress on the parking pawl in the trans.

In the G, when parking on level surfaces, just the parking brake, when on inclines, leave it in 1st or reverse (6mt) in addition to the parking brake.

 

I agree, the pawl is functional thought it still might be damaged. And not just the pawl, the ring teeth might be damaged, too.

I have used parking brakes in vehicle I've owned since 1976 regardless of trans type.

https://goo.gl/images/LBbVcb provides a couple of drawings to show what it is and how it works.

 

It's probably fine. Does park still hold the car?

 

Yes, "park" still holds the car on a flat surface, while on an incline facing downward and on an incline facing upwards.

I am hoping it is fine.