Gear problems in my 2008 Ford Territory

The original slipping could have been caused by low transmission fluid, which would also explain why the unit would not select a gear. That would suggest that the transmission has a leak somewhere, because it’s a sealed system and doesn’t need periodic top-ups.

The danger, however, is that running the unit with a low fluid level has caused damage to the mechanical parts of the gearbox and possibly the torque converter as well. That’s because the fluid in an automatic transmission not only provides the drive, it also lubricates the various bits of the transmission. Not enough fluid means not enough lubrication.

If it was a as simple as low fluid, now that you’ve changed the fluid and taken it back to its correct level, you should have all the gears working again. But the fact that it will only select first and second gears suggests damage has already occurred. This is really a job for a transmission specialist who will be able to accurately diagnose what’s wrong.