Why toyota surf 3.4ssrg v6,gear stucked on parking position after towing a trailer what can be the problem?

SOURCE: 2001 toyota tundra towing issues

There are a number of aftermarket kits specifically made for your vehicle.
I did a quick search on yours, and here's what I found

http://www.etrailer.com/pc-VWH~118378.htm

Not a bad deal for $55, and it's all plug and play.

SOURCE: toyota surf automatic it wont change gear ?

I assume you are saying it is late to shift. There is what is called a Throttle Valve ( TV) cable that goes from the engine to the transmission. If this cable is out of adjustment, or too tight, it will cause this problem. While you are at it check for vaccuum leaks on the hose from the engine to the tranmission. A problem here will cause a harsh shift, but necessarryly late shift

Good Luck

SOURCE: what gear to drive in when towing a trailer with toyota camry

Whatever gear the car needs to have the moter spinning without full throttle.Auto and manual are driven differently.Up hill,downhill.Mostly,if its manual you wait a bit longer to change gears.E.g.Normal change revs,3000 rpm,go to 3500rpm with the trailer on.Auto,use the gear selecter and put it back to 3 instead of D and when the car has enough speed,then into D.Drive the auto like a manual on hills etc.to help it.Don't forget that braking distances almost double when you have a trailer on.Hope this helps

SOURCE: I cannot shift gear from park "P" position when

shifter interlock motor bad