Can A transmission make a knocking noise when truck is not moving ?? my mechanic seems to think it could be some kind of pump or the torqe converter in the tranny what else could it be near rear of engine ?? It does sound like its comming from the tranny. It currently shifts and drives fine. this is a 1986 turbo 4Runner automatic A340h

 

that's pretty hard to diagnose with out tearing into it man, i was thinking maybe a cracked flex plate too,its pretty wishful thinking cause its gonna be the cheapest, i think its just time to get in there and drop the tranny.

 

Yes the transmission can make a knocking when it's not moving. When stopped, your torque converter and flex plate within the bellhousing are still moving. If something was loose in there, it would make one heck of a racket.

 

Does the noise increase in frequency when you rev the engine?

 

If your flex plate does have a crack in it a quick way to check it would be turn the engine off, push that gas pedal halfway to the floor and start, if it is cracked the immediate tq will make a LOUD crack/bang noise