clunk noise, 2000rpm to 1500rpm kick down at 30mph

Having replaced my 2015 Cherokee, due to transmission issue, I bought a second hand 2012 Grand Cherokee Laredo X from my local dealer, back in Aug 2015.

Since then, i have had the car into the dealership several times to fix a loud clunking noise, which can also be felt whilst driving.

If you accelerate to say 40mph, and let the car coast, once the revs get to around 2000rpm, the car jerks, the rpm drops to 1500, and the noise is heard.

The Dealership has reflashed the software 2 times and installed a brand new software, literally 3-4 weeks ago, which everytime solves the problem for about 2 weeks, and then the clunk / jerk can be felt and heard again.

i am going into the dealership tomorrow, to see what they can do this time - fingers crossed.

2012 Jeep Grand Cherokee Laredo, 3.6 V6 engine, 5-speed transmission. Problem only just started as it feels like the transmission does not know if it wants to shift or not. Almost like riding with someone who is just learning how to drive a manual transmission car. RPMs rev or decrease at random times, although the vehicle does not increase or decrease in speed for the most part. Certain downshifts will cause a random clunk sound that can be felt on the driver's side floor. There is no consistency to the bad shifting or clunking and I cannot replicate the symptoms on purpose. Vehicle was purchased used in July 2016 and was not having problems before this.

I bought my Jeep Grande Cherokee Limited Edition second hand "23,000 KM" and since the day I bought it I have noticed countless issues but most majorly was the transmission:

I have always noticed hard jerking sound in the back of the car which felt like someone bumped you from the back. but most recently a new problem raised... where the "Electronic Throttle Control" light appeared (for 1 second) on the dashboard while I was driving causing the car to slow down and cruse control to release and stop working, however this is temporary until I switch off then on, everything goes back to normal... but it happens again and again...

I went to the dealership they told me that the throttle control is causing both problems (the jerking noise in gear shift and the release of cruise control).

I sent the car to dealership yesterday and they ordered the part, but still didn’t install it... I will update you once I receive the car and hopefully this fixes the problem.

Update from Apr 30, 2015: I went to the dealership and fixed the problem; and in the same time I wanted to conduct my 60,000KM service the dealership basically conducted the following:

- Checked the Electric Throttle Control Light - Checked the 4WD & Traction Warning Light

1- Performed recall Number R09 2- Preformed RRT 14022

And under my extended warranty they changed the Transfer Case Module which they said was causing the problem... I dont know if that fixed the problem or not!

One advise... if your vehicle is still under warranty, ask to extend it using Chrysler extended warranty system especially in jeep... this is because electrical problems will start immediately

At about 16,000 miles, I was driving on the 241 Toll Road up a steep hill going approximately 65 mph and the engine down shifted into a lower gear, the engine began revving high, the RPM went high, and I lost speed. I pulled off to the side of the road. I put the vehicle in park while I called my husband because I did not know what was happening to the vehicle. I wanted to let him know in case I was stranded on the side of the road. We decided we wanted to try to get the vehicle home, if possible. I put the vehicle back in drive and got back on the highway and it did not do it again and I made it home. It has not happened since but other issues have started such as stalling, and not starting or able to shut off car.