Need help - AE86 SR5 downshifts

[pinoy]

I have an automatic ae86 SR5 as my winter beater. The car drives smoothly but is giving me some problem recently. While driving between 100 to 110 kph the car downshifts to a lower gear and does it several times. I have read in the forum that is related to the adjustment of the kickdown point. I consulted some friends and they say it has something to do with the speed sensor. I consulted my mechanic and he says its the transmission. I hate to think it is the transmission.

I need your help and advice. I don't know if this is related but before the car downshift I hear some clicking sound somewhere around my dash.

I also would want to know where the speed sensor is.

Thanks in advance.

[REN69]

If you have an OD button on it, chances are the OD button is almost dead.. my dad's 84 LE Van used to do that.. the overdrive button was gone.. it used to piss me off when I was on the highway cuz it would do it like once every 5 minutes.

If you don't have an OD button (and even if you do) are you sure the car is not going to a lower gear because you're pressing the gas pedal too far?? I know SR5's are slow, specially with automatics.. so if you're trying to get the car to speed up, chances are the transmission is gonna keep doing that till it gets to a higher speed.