I've had my 99 4runner for a couple weeks now and I'm experiencing a very noticeable "jerk" that I feel in my seat and not just the steering wheel when I very quickly let off the gas when going at speeds around 50Mph and over.

It doesn't happen if I ease off the gas or if I'm going under around 50 miles per hour. I read that this could have to do with shifting out of overdrive or something like that but it happens even with overdrive off.

I just greased the entire driveshaft two days ago and I didn't notice this issue before I did that but it could've just been because I wasn't paying attention before that so I'm not sure it has anything to do with that.

Any ideas or is this normal?

 

I've got a 99' 4runner also. Yes it does the same thing. I'm thinking it is a normal thing? not entirly sure. I drive forklift for a living it maybe an auto de-cel ( deceleration ) built into the computer programming to declerate the engine without breaking force on your wheels. But thats just a guess. When you do let off your gas right when you do it look down at your shifter you will see it move forward a bit. It almost seems like the trani isent mounted properly. But i'm no expert or mechanic.

 

I've just started to notice this with my 99 tacoma, did either of you guys ever figure out what is causing this?

 

have someone else drive your truck/ runner and you follow them in another vehicle and watch your rear axle. if the axle rolls backwards when the truck jerks then that's your problem. mine is doing that and i realized it last week when i was following my dad. my truck does it every time i change gears. im in the process of finding a fix for this, but ill let you know when i find out.

 

one cause is that the propeller shafts needs greasing