If your truck has a black chassis, then you have a 3906 e-maxx. All the 3906's are the same except the earliest versions used narrow a-arms which are hard to find now, and the least desirable. They went to a widemaxx version later and you can always upgrade to that if yours is the narrow.

The 3906 e-maxx is a pretty good truck. I have owned a few of them.

They are very reliable with stock power. Should go about 25mph and the low range is nice off road. If you go brushless, the driveline will suffer. You'll start breaking shafts and with enough power, the diffs will give up too.

There is a fix, but it involves spending around $70-100 on ebay to upgrade everything to the new brushless driveline.

Another bad thing is the 3906 wont easily accept lipo's or 7 cell NiMh batteries without some modding or different battery straps.

The orange 14.4v EVX esc will work fine on 16.8v. Most say it is more reliable than the newer EVX2. However, on 16.8v you may notice the truck cuts out at full throttle until the batterys start to run down some. This is just a built in function of the ESC when it knows it has more than rated voltage. Once the batteries run down a little it will quit cutting out.

The transmission alone on a 3906 e-maxx will fetch $50, and the whole complete rtr truck will bring $150+ in decent shape. You got a good deal no matter what. Also, everything on the truck can be upgraded to the new version, however its normally cheaper to sell the 3906 and buy a new version than it is to upgrade the older truck, so keep that in mind.

As for the steering, thats normal. The servo isnt the strongest stock and the servo saver is a bad design that flexes too much, but it usually works ok as long as the truck is moving. The newer e-maxx has a much nicer steering bellcrank setup you can upgrade to for about $15 if you decide to keep the truck.

Hope this helps!