Our company has a Cat TL943 made in 2008, it was manufactured by JLG and I have ran it quite a bit. We are pretty hard on it and it has held up pretty well but it is weak. It has foam filled tires, these are to heavy for the drive train. You can not operate it in 4th gear without it overheating the axels because of the foam filled tires.
I know 4th gear is not used that often for most operating but we do lots of work close to town and like to road it to the job site when we can. Even operating it in 3rd gear for very long is to hard on it. I understand this is due to the foam filled tires but when we purchased this piece of equipment this was never mentioned as a side affect of the foam filled tires. I do not know if this is only with this brand and model or if foam filled tires will do this on any brand and model.
Another problem is when you are scoping in the boom the engine will not stay reved up, it lugs down and will even die, this is with no load on the forks. When you have a load on the forks that is over 2000lbs (approx) the forks will not tilt up. I think there may be a problem with the hydraulic valves but this should not happen on a piece of equipment with 1000hrs on it (we bought it with 1000hrs on it, so not from us abbusing it).
One good thing about this telehandler is even after us running it thru brush it has held up well, no damage to it even thought the engine compartment is fiberglass and the wheel wells are plastic but other than that I do not like this CAT telehandler. I know these are not made to be ran thru brush but we use it in the field to unload and drag pipe on pipelines sometimes.