Vaccuum hose coming from transmission isnt connected to anything

your sure its not the tube that goes to very top center for vent tube ,if it isnt that one it could be for the vaccum port on side of transfer case for 4 wheel drive vaccun switch usually most of newer vehicle have went to electronic soleniod

The hose in question is a vent for air to your tranny

could be a vacuum leak at a hose or gasket. with the engine running spray a little carb spray at the intake manifold area. if the idle picks up you are close to the vacuum leak. dont spray on the exhaust manifold area, be careful

it some time is connected to the transmission bolts or side of the engine

nothing. they are breather hoses

Possible causes - Intake air leaks
- Faulty front heated oxygen sensor
- Ignition misfiring
- Faulty fuel injectors
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Faulty Mass Air Flow (MAF) sensor
- Incorrect Positive Crankcase Ventilation (PCV) hose connection

the problem is fuel related and nowhere else
it indicates a vacuum leak , either at the manifold , brake booster , transmission actuator hose/unit for the transmission or hoses that control under that dash
bad at stopping at light indicates that it is the brake booster
simple test is to put the hand brake on, start the engine and if it idles ok , put your foot on the brake
if still ok move vent controls ,
if with the foot on the brake it plays up , replace the brake booster

If this is out ot the top of the tranny,it is a vent line ,for fluid expansion or when you add fluid ,as long as it is not plugged up ,it's fine

If you are talking about the hose that runs by the dipstick then it doesnt connects to nothing its supposed to be an transmission overfill exit

sorry lost here ,never seen one but if transmission shaft is turning to front diff then the problem is their,could be anyting from a sheared diff pinion to a broken planet wheel or possible evan a snapped half shaft or the spline on the end of the half shaft has worn and rounded off