Clunk in rear end

A friend that I purchase 2017 4Runners about a month apart. They are exactly the same and every way except color. I have a steep driveway and sometimes while I am on the approach for the garage, and in the drive gear with no four-wheel mechanisms engaged, the car will roll backwards a few feet while waiting for the garage door to open. When I accelerate to enter the garage there is a loud clunk from the rear end and the anti-slip light flashes on the dash. This is all momentary. My friends 4Runner does exactly the same thing on my driveway. Has anyone had this happen to them? The dealer just told me that since both vehicles do the same thing that it must be normal. This is what I need to know. Any ideas? Thank you

 

Mine will do this occasionally on a steep hill. I think it has something to do with the hill holder. I can’t remember if a particular sequence sets it off. Like whether I’m coming off the brake or not. I’m not near my manual for the proper terminology.

 

the toyota has this anti roll back and then the brakes come on ... so in drive on a hill/grade take foot off the brake vehicle rolls back yes it is how its built. makes all sorts of noises dash lights up clicking clunking etc..

now if these had a V8 engine this would not happen . my GM trucks and other V8 engines never did this.. I placed my SR5 in drive foot on brake then took foot off brake and as it moved to the gas pedal vehicle rolled back and hit my boat trailer caused a small distortion in the plastic rear bumper .. that was when I first had it a week old .. not happy these do roll back very easy on a slight grade..

 

I too have a steep driveway. And with all auto transmissions there is roll back at idle. Just practice learning how to drive with both feet (1 foot on the gas & 1 foot on the brake), just until it gets rolling and then remember to not rest your left foot on the brake or clutch pedal. I've done this with anything I drive, from sand rails to heavy equipment. And heavy eq. operators learn this early in their job. I just retired from 34 years of it. Don't rely on the "hill hold" nanny. Respectively.

Steve