I have a TL130 and you can likely do it. We lift and move 3000 lbs pallets of wall blocks all the time keeping it very low to the ground. The higher you have the load, the more tippy you will get. Make sure the truck is on level ground or the machine is positioned facing up hill. The ground must be very firm with no chance of sinking of the machine tracks. Make sure the forks are all the way in and whatever your lifting is right up against the backrest. Then test to see if the machine will lift the load without tipping. If it lifts the pallet ok, then slowly move back until the pallet just clears the truck and lower. You can also have someone drive the truck forward. Lower the pallet ASAP. If possible, lighten the pallet a bit.
What do you need to lift? Lifting with a sling is not going to work to get it off the truck.