I do agree with @gautam
however we can make a try to check the ATF condition first if it looks fine we can replace transmission filter and top-up oil level and run it on D on the workshop lift for 15 min. then make a test drive and see
the issue is GM design depends much on oil pressure if we lose the pressure for bad torque converter or bad filter or low level oil we start to get indications if recover early we may avoid extra costs of replacing valve body and internal parts.
Unfortunately, Escalades are known for their bad transmissions. The problems with hard or difficult shifting is a known issue, and the problem is almost always related to the valve body.
If you are not familiar with automatic transmissions, the valve body is an arrangement of valves, check valves, and other components that control the flow of fluid through the transmission to shift gears by rearranging the relationships between the various planetary gears that give a transmision "ratios" like a manual transmission.
Automatic transmissions also have a clutch pack that holds the planetary gears in position while the transmission is in any given gear. These clutch packs are engaged and disengaged by hydraulic pressure from the pump in the transmission, but the actual circuits that control the movement of the clutch packs are controlled and regulated by small valves in the valve body.
With Escalades (and other GM transmisions), some of these valve sometimes stick halfway open or closed, which means that the clutch packs often do not fully release to allow the planetary gears to change position relative to each other, and it is this what you are hearing when you say you hear a scratching or grating sound. In effect, the transmission is still in gear (or neutral), but because the clutches are still partially engaged, it is often impossibe to move the selector lever without breaking something in the transmission.
The problem is that this kind of problem can appear suddenly. The transmision may be fine for years, but the next time you want to engage a gear manually, it does not work, just like you are describing. However, fixing the issue is not always as easy as replacing the fluid, since the valve that is sticking sometimes has to be freed by hand.
This is not always the case though, and a fluid replacement might fix the issue, but don't bank on it. If a fluid replacement does not fix the problem, you may have to replace the transmission because repairs are almost just as expensive as a replacement.
Moreover, if the technician repairing your transmission is not an expert, chances are excellent that you will end up experiencing other issues when you get your car back. The transmission could be noisy, not shift correctly, or not shift at all, so you may want to consider replacing it instead of repairing it.
I really enjoy driving this amazing beast or a luxury car on Dubai road. It been one of the most special car to after coming to Dubai. I love this car a lot.
I would like to raise one small problem happen last night after visiting Dubai mall. Everything was going great and I went to mall with my family to enjoy some shopping, well the car was park when I reach without any hassle. But when I am back to get my car from parking my family was waiting to the exit door I notice a problem in shifting from ""P"" to ""D"" mode. When I was trying to move the gear lever from parking to drive mode it was making a scratch sound. I did not realize what has happen, I tried at least 6 time to get it to the driving mode but all the trial was failed with scratching sound. I was scared I don’t know what has happen suddenly to the car.
I came down from the car and give a final try after 10 minutes, I pushed brake and tried to remove a safety key and put it back and tried again, this time with the god grace it started and easily shifted in to drive mode. I don’t understand how!
But again now at this time after reaching to my home safely I found another problem where I was not able to shift the gear into ""R"" the shifter was not catching the gear! Well at 11 pm in the night I did not bother to indulge more time, because it seem my car had a severe issue in shifting gear into ""P"" and ""R"".
I hope I am thinking in a right direction?? Is gearbox gone for a toss? Is there any cheaper fix to repair it, as I am sure gearbox in this big beast must be damn expensive. Any cost effective ideas guys....?