Auto transmission?

I've got a 2007 DCSB with V6 and auto. Occasionally when I come to a stop the truck will sit quietly for a few seconds and then try to lurch forward. It doesn't move but it feels like someone just bumped into me going about a half mile an hour. Is this possibly a torque converter issue, valve body, or simply low on fluid?
I bought the truck from a dealer last Aug and I assume they checked it before the sale. There is no leaking fluid visible underneath.

 

Low on ATF WS Fluid !

 

It sounds like axle wrap or something with the leaf springs, very common issue in pick up trucks it would seem. I don't think it's anything wrong with the tranny but I could be wrong.

 

You are, axle wrap happens on acceleration not when at a complete stop. It's the transmission and it could be low on fluid. I did a full flush on mine and I was 3/4qt low, I don't notice the bump anymore at a stop.

 

Well I'll be damned. I had a similar issue in my old truck and just thought it was something with the axle

I was going off of this thread here

 

But in this case the OP said he is stopped for a bit before it does it. I guess it could be axle wrap if it unloaded as you stop. This thud he described sounds identical to what I was feeling and it went away after the trans fluid was corrected.

 

Thanks for the help, I'll have it checked out Monday.

 

Not hard to check yourself, just follow the diy on this link. https://www.tacomaworld.com/threads/how-to-drain-refill-automatic-transmission.63851/

 

I see, I get this sometimes in my 2014 I just purchased, only once in awhile, usually while on a grade now that I think about it. Sounds like I might need to check mine as well. Thanks for sharing

 

Is your defroster on? This happens when the AC clutch engages.

 

I think we may have a winner! I drove it all around the last 2 days without the defroster on and it hasn't happened once. I'll update in a few more days just to be sure.

 

yep, ive noticed this with the defrost or A/C on as well. the clutch kicks in and the engine speed increases slightly to compensate.

 

Yeah. My truck does this when the ac or defroster is on.

 

Yeah I asked the same question... AC or Defroster. Turn off your AC or put it on Air only and see if the problem persists. Mine did not.

 

My 2013 does it with the defrost or AC on. I just press the brake pedal a little harder than I use to all the time and really don't feel it anymore.