Hello, I am looking for some advice as my mechanic is stumped by my cars issue. I have a 1996 Toyota 4runner with a possible faulty transmission relay. When the relay is plugged in it starts clicking/humming. The truck as I move forward seems to be trying to engage 4wheel Drive. Clunk!!!! When I pull the relay out, the truck drives as it should. Are there any negative effects of driving the vehicle without the relay? Any help would be greatly appreciated. I love my 4runner and want it to reach 500k