Did you get the towing package from the factory? If you didnt, the only thing you didnt get was the mechanical cooling fan which is ran by the water pump. You will just have an electric fan which is ok. The mechanical cooling fan will help with cooling at low speeds and on those long hill climbs(if you have hills) You will of course need to add a hitch and wiring if you have not already.
If you are worried about the transmission then you can look into getting a bigger tranny cooler for it. You already have the stock cooler which sits in front of the condenser but its cooling capacity is limited.
Overall you should have no problems towing 3,000lbs with the liberty. Just make sure you keep the O/D off and take it easy. I tow that much and while it does ok, I wouldnt want to tow it long distances if I know there will be a lot of hills. Only problem with that, hills is all we have around here..
Actually Ill be towing a camper around 1.5hours tomorrow. Loaded we should be just a tad over 3,000lbs.

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Current Jeep: 2004 Jeep Liberty
-Atlantic Blue
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