Repeated intermittent clicking noise from around transmission area when shift from all other gears to "Park"

[diy_sang]

I'll start with the details of the car:

2010 Yukon Denali AWD
Transfer Case BW4485
Transmission: 6L80E

Current issues/condition:
No Check engine light on.
No error codes with an OBD2 sensors.
ABS light stays ON
SERVICE STABILITRAK ON
TRACTION CONTROL IS OFF
TRACTION CONTROL (PICTURE) IS ON

So here is what happened:

This isn't my automobile it's my brothers. He had changed out his brakes (all 4) about a week before this issue arrived. He was driving to work one day and right before he got there, the car was making a grinding noise. Later in the day we inspect it and it seems that he wasn't able to put the car in DRIVE without it grinding or making the grinding noise badly. Although when he had it in PARK or REVERSE there wasn't any noise whatsoever. We ended it getting it towed back home.

The next day we had to reposition the car onto the driveway so we have a better look, we managed to put in REVERSE for a bit but soon it started to grind again.

We then ended up pushing it onto the driveway, we then inspect underneath and listened for the sound as we try to replicate the sound by shifting the gears. My cousin who was present and also a mechanic (not sure how well he is), stated it's a possibility it'll be coming from the Transfer Case.

Here is where it changed.

Just to note the driveway is at a bit of an incline. As we were continuing to inspect the sound, it NO longer made a grinding noise when shifting into DRIVE or REVERSE or NEUTRAL, BUT when shifting out of those gears into PARK, it made a repeated but intermittent clicking noise like a lever was trying to catch onto something and then stops, all while the car still stayed on without issue.

The conclusion here:
It's NOT the Transfer Case since I have removed it from the transmission.
I removed all driveshafts.

I replicated the sound by shifting the gears like before and the sound persists there, as a repeated, intermittent clicking sound like I had explained above.
I've searched through forums, youtube, websites, and I can't seem to pinpoint the issue.
One other possibility I'm assuming is that it could be the Parking Pawl.
But before I go ahead and take the transmission out (which I'm trying to avoid to do), I want to know if anyone here have any ideas or experience anything like this?

I will try to upload a video of the whole sound and what I did.

 

[swathdiver]

I'll start with the details of the car:

2010 Yukon Denali AWD
Transfer Case BW4485
Transmission: 6L80E

Current issues/condition:
No Check engine light on.
No error codes with an OBD2 sensors.
ABS light stays ON
SERVICE STABILITRAK ON
TRACTION CONTROL IS OFF
TRACTION CONTROL (PICTURE) IS ON

So here is what happened:

This isn't my automobile it's my brothers. He had changed out his brakes (all 4) about a week before this issue arrived. He was driving to work one day and right before he got there, the car was making a grinding noise. Later in the day we inspect it and it seems that he wasn't able to put the car in DRIVE without it grinding or making the grinding noise badly. Although when he had it in PARK or REVERSE there wasn't any noise whatsoever. We ended it getting it towed back home.

The next day we had to reposition the car onto the driveway so we have a better look, we managed to put in REVERSE for a bit but soon it started to grind again.

We then ended up pushing it onto the driveway, we then inspect underneath and listened for the sound as we try to replicate the sound by shifting the gears. My cousin who was present and also a mechanic (not sure how well he is), stated it's a possibility it'll be coming from the Transfer Case.

Here is where it changed.

Just to note the driveway is at a bit of an incline. As we were continuing to inspect the sound, it NO longer made a grinding noise when shifting into DRIVE or REVERSE or NEUTRAL, BUT when shifting out of those gears into PARK, it made a repeated but intermittent clicking noise like a lever was trying to catch onto something and then stops, all while the car still stayed on without issue.

The conclusion here:
It's NOT the Transfer Case since I have removed it from the transmission.
I removed all driveshafts.

I replicated the sound by shifting the gears like before and the sound persists there, as a repeated, intermittent clicking sound like I had explained above.
I've searched through forums, youtube, websites, and I can't seem to pinpoint the issue.
One other possibility I'm assuming is that it could be the Parking Pawl.
But before I go ahead and take the transmission out (which I'm trying to avoid to do), I want to know if anyone here have any ideas or experience anything like this?

I will try to upload a video of the whole sound and what I did.

Seems to me it is the shift linkage up under the transmission pan. It is either bent or has come loose. Also check the plastic pieces on the side of the transmission's shift linkage.

There is a good video of it here at about 4:45 in:

 

[OR VietVet]

I lean toward the parking pawl too but need to inspect what @swathdiver recommended too. Need a mechanic's stethoscope to pin point the noise location and what is possibly in the trans case where the noise is. Also, this noise is likely not related to the grind noise. Maybe @rockola1971 can chime in with his transmission knowledge.

 

[Doubeleive]

I would also inspect the flex plate, there should be a inspection plate on the bell housing use a mirror and flashlight
is the clicking constant or does it change with rpm?

 

[swathdiver]

I lean toward the parking pawl too but need to inspect what @swathdiver recommended too. Need a mechanic's stethoscope to pin point the noise location and what is possibly in the trans case where the noise is. Also, this noise is likely not related to the grind noise. Maybe @rockola1971 can chime in with his transmission knowledge.

Forgot all about the pawl, but yes, could certainly be that!

 

[rockola1971]

Its odd all this chaos after a brake service. I would check to see if any of the brake pads were put in backwards and make sure none of the warning fingers are bent inward toward the rotors. How sure are you the noise is coming from the tranny?

 

[diy_sang]

Thanks for the helpful solutions everyone, I'll check on those ones. Unfortunately I haven't had a chance to work on those ones above but started on working on figuring out why the ABS light stayed on, we even bought two new ABS sensor and replaced the front ones but still showed up on ABS on the dashboard, also ending up stripping a bolt on the brake caliper bracket and also will be having to replace a new complete brake caliper since the brake boot ripped and came out.

Any helpful tips on solving this ABS issue is helpful but since brakes are still working as far as intended the main issues still remain with that sound.

Also here is the noise it's making when I'm shifting from all other gears into Park.

 

[swathdiver]

Thanks for the helpful solutions everyone, I'll check on those ones. Unfortunately I haven't had a chance to work on those ones above but started on working on figuring out why the ABS light stayed on, we even bought two new ABS sensor and replaced the front ones but still showed up on ABS on the dashboard, also ending up stripping a bolt on the brake caliper bracket and also will be having to replace a new complete brake caliper since the brake boot ripped and came out.

Any helpful tips on solving this ABS issue is helpful but since brakes are still working as far as intended the main issues still remain with that sound.

Also here is the noise it's making when I'm shifting from all other gears into Park.

Definitely related to the shift linkage and parking pawl. Does the owner not use the parking brake?

If its just the shift linkage, that can be fixed without disassembly.

Gears Magazine - 6L80/90E Park Rod: "A Closer Look"

Have you ever had part that you’re not sure about, and wonder if you should use it? It looked good, but there was just something about it! At some point in time, we have all encountered situations where a part was in question. It looks good enough to use, but you didn’t feel right about […]

gearsmagazine.com

I don't have my 6L80 shop manual handy for better info on the internals...

 

[swathdiver]

Something funny is going on, let me send them to you.

 

[rockola1971]

The video shown above is completely normal and stop doing that! What you are doing there is the same as cruising down a city street and slamming it into park! You are not getting the tranny to stop movement of its output shaft BEFORE you put it in park. There is no load on the tranny (driveshaft/rear axle/wheels/weight of vehicle) since the driveshaft and transfer case have been disconnected. Is this the same noise it is making when everything was installed (driveshaft, Tcase, etc.)?

The noise in the video is definitely the parking pawl trying to engage the sunshell notches and skipping across them because the tranny is still in rotation and not at a complete stop. Nothing but the shift cable and its adjustment controls the parking pawl. It is NOT electronically controlled. It is 100% mechanical.

If your cable is out of adjustment, it is because something failed or is worn (likely outside of the transmission). Check linkage at shifter, look for worn/split/missing nylon bushings. Inspect cable connection at transmission shift lever. Look for worn/split/missing nylon bushing. Inspect cable retention at bracket mounted on transmission. Inspect for cracked, stripped, broken off housing. Loose mounting bolts bracket to tranny.
Shift cable adjustment:

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