I have a 2000 4runner with 182K miles on it now, i have just done a bunch of maintenance on it lately including plugs, wires, filter, alternator, fuel filter, all fluids. When i did the tranny i just simply drained it and filled it back up with conventional toyota atf 3 quarts or so but no filter change cause the dealership stupidly told me there was no filter. After not knowing how long it has been since it has been flushed or changed would it be wise to do a full flush and filter change? Was thinking of switching to all synthetics at 200k miles with tranny, diffs, motor and transfercase. I have synthetic/conventional blend in the engine currently?