If the turbo has in and out play, then the oil seals are taking a beating. It can have some up and down play, remember the shaft rides on a cushion of oil inside the bearings. What we don't want is in and out play. This type of wear will eventually take out the oil seals on the shaft and you will get oil leakage out both sides of the turbo. Oil out the turbine side will immediately burn once it hits the blazing hot exhaust stream, resulting in smoke. If not corrected, once those seals go out and in and out play gets more and more excessive, eventually the compressor wheel will start cutting into the backing plate under WOT, and into the compressor cover under decell. Also, the turbine wheel will start to touch down inside the turbine housing as well. Leading to catastrophic failure.
If you have in and out play, the turbo needs to be rebuilt. I would also recommend if you are still running the factory oil cooler inside the radiator, to discontinue using it and run some form of oil filtration setup for the turbo. Either one of Precisions Oil Filtration kits (#1 recommendation) or one of the oil feed line filter kits.
Hope some of this helps.
Patrick
