Hi all, I have a 09 4runner with 106,000 miles. A couple months ago I noticed the car lunged or bucked after coming to a stop and taking your foot of the brake as if to accelerate again. It feels like the tranny is dropping a gear to go again but very hard with a thug. My mechanic said it could be a broken engine mount but it's never been in an accident but does drive on a dirt road. We just serviced the tranny with new filter gasket and Amsoil signature ATF. Seemed to do fine for 2 day but the problem came back. The magnets were clean and the oil was well used. Mechanic said it looked fine but I told him to jump the diagnostic box like the manual said but he did not do that. I just greased all joints and couplers. The tag/ buck feels like its coming from the middle of the car. Shifts reasonably smooth for having 106k on it. Any ideas are appreciated. Thanks, Chad

 

Well, is it really a lunge or buck? I'd say if it's what I suspect it is, don't worry to much. If it's more of a "clunk" , "thud" or "thump" it's a noise from where the driveshaft fits together about half way back under the rear seat area. There are multiple threads on this across multiple message boards. Some people experience this while still under warranty, others like you get up in age before they find it. The bad news is there's no good remedy that works. Some guys even have a new driveshaft put in and it still does it. The good news, is there isn't any evidence (that I found) of real problems associated with this. I'd say check the grease zerks under there and make sure they're lubed. For me it's much more intense when the A/C is running, likely due to the elevated idle & torque as a result.

 

Do you have any links to those threads?

 

2 minute search of "driveshaft clunk" There are plenty more out there.

https://www.yotatech.com/forums/f117...-clunk-138641/

https://www.yotatech.com/forums/f117...t-info-130447/

https://www.yotatech.com/forums/f117...pension-79867/