Strong spike/jerk in acceleration

Did a quick google search and found this http://m.carsdirect.com/car-repair/how-to-install-a-transmission-valve sounds about right

 

It bumps/clunks while you are braking or just after the vehicle has stopped?

 

I get a bump/loud clunk downshifting when it goes into 2nd gear, pretend you have a bowling ball in your truck bed and when slowing down coming to a red light it slams into the front of the bed

 

When you say bump, it's something you can feel; liked stored energy being released?
Maybe your slip joint is binding a little. Mine would bind and clunk every now and then the first 1,000 miles or so. I'm now at about 7,000
How many miles?

 

It is likely a valve body pressure issue or a failed torque converter. Is you tranny fluid level correct?

 

Im almsot at 20k ! I wouldnt call it stored energy being released. If it was the slip joint binding, I think ill feel it durning the day? but this issue is only when the truck is cold especially in the mornings or when left parked for a while in the afternoon

 

It was just filled about 1qt two days ago im about to hit 20k miles

 

So, your transmission is now at the right level, right??? I am curious, are you still having the bump symptoms when cold?

 

Oh wow...ok.
I've said it before; I think a lot of the stink surrounding this transmission is the flex(intermediate) lockup strategy implemented by AI. Google it; it's a thing with Tundras, RAVs, Camry...
In your case, it might be componded by running a quart low for 20K miles.
Your fluid viscosity could have sheared down, not allowing the TC clutch to operate properly.
Has it just started happening recently?
Have you tried duplicating using S mode?

 

Taking it a step further, try a cold run in "S" mode, as splitbolt suggests. We are curious what you will find.

 

I think you're idea about valve bodies has merit, in the fact that Camrys have a T-SB for pan magnets.
A reflash was attempted earlier on...
Whether it's software, hardware, a combination of the two...who knows?
Lot's of fried torque converters and extended warranties issued as a result.
I mention the Camry, because a lot of it's symptoms mirror what's been reported with the Tacoma.

 

According to the dealer yes it's at the right level and I hoped the clunk was gone but next morning it did it again.

Nope has been happening ever since i owned the truck at first i thought it was "breaking in" but now im sure it's broke ha!

Thanks for the input guys! Will try it tomorrow morning, will start it let it warm up as usual and take off in S mode.

 

@splitbolt @bradwhitenikki found the same symtom on a jeep http://www.jeepsunlimited.com/forum...40-Slowing-down-abrupt-transmission-downshift
but no solution

 

Did some looking around over there...
http://www.jeepsunlimited.com/forum...rd-Downshift&p=4478351&viewfull=1#post4478351

About what I've been saying about AI/flex lock up.

Similar to Toyota, the program and/or hardware, seems to have a problem with inconsistent throttle. Our low torque engine, 6-speed transmission, and anemic rear gear don't help staying consistent with throttle input.

S-mode cancels AI/flex lockup.

 

Agreed. My service manager, and his master tech think so as well. My service manager was a transmission repair guy before the step into management.

 

@splitbolt @bradwhitenikki

Tried it this morning in S mode same deal, it kind of felt less noticable but maybe it was just in my head, ill give it another try tomorrow. Thanks guys!

 

Work with Toyota corporate on that one. It sounds like you have something serious going on.

 

That's the plan! Already have a case open, the thing is the dealer cant duplicate the problem, im going to ask for a loaner and have them keep it for a week, i wouldnt mind going every morning to the dealership and test driving it untill we duplicate the problem.

 

You might have to leave it overnight.
If I was in your shoes I'd do a ATF analysis regardless of what the dealer says.
Most who have an analysis done on Toyota ATF WS, change every 30K; 60K tops.
I plan on changing mine out and analyzing at 10K and every 30K thereafter.