RPM needle jumps when braking

I had the dealer replace the timing cover gaskets, valve cover gaskets, water pump, drive belt, and the trans rear tail shaft seal. This was done yesterday. As I drove to work this morning, I noticed something odd. When I'm at say 50mph and apply the brakes, the MPH needle decreases as usual, and so does the RPM needle. The RMP needle decreases, but once I let off the brake (without quickly pressing on the gas pedal) the RMP needle jumps a tad, but continues to decrease. Any thoughts? This is on an 07 Tacoma Prerunner, V6 Access Cab with the TRD off road package. It has 230,000 miles, and had a major service done about a month ago.

 

Update: It seems like the only time the RPM needle jumps is when decelerating and when the RPM needle is approaching 1000RPM from a higher RPM. Can anyone test this out on your 06-12 Tacoma to see if this is normal? Ideally, you would be at a speed in the 2000 RPM range, and then you would decelerate. I am curious if the RPM needle jumps a bit once it is near 1000RPM. Mine jumps a tad, but then continues to decrease. Thanks.

 

i bet its the torque converter unlocking

 

Is this normal?

 

If you have the tow package, some tacomas will downshift when braking/decelerating to help with the push/added weight of a trailer behind you. My 2012 sport dos this.

 

Thanks. I do have the tow package, but have never towed anything with it. I have also never really noticed this change in rpm as I slow down. I thought maybe it had something to do with the new serpentine belt, but I guess your explanation sounds correct.

 

I'm thinking you may have not noticed it before (?). My 07 Taco V6, 5spd auto has done this since the day I got it (not all that long ago, I will admit). It only has 80k miles on it. Same set-up; TRD Sport 4x4, tow, etc. I haven't paid much attention to it as I assumed it was the down shifting or torque converter thingy letting go.

I HAVE noticed what Polar Bear refers to when I am going down a hill on the highway at speeds above 35 or so. It seems to know that it needs to do more than just reduce RPMs to idle (like my wife's "down hill racer", the Buick Lacrosse). It shifts the tranny to a lower gear or higher torque value (I guess) such that it "holds back" a bit. Really nice feature when you live in areas with speed traps.

 

Gotcha. I never noticed it before, but I guess you all are right. I dropped it off at the dealer on Monday, and after several hours, they reported the same thing - downshifting.

It really only happens when I'm slowing down after having built up speed. If I'm just traveling at 20mph and slowly come to a stop, the RPM surge doesn't occur. So in retro, it makes sense.

 

Though, I wonder if TSB-0393-09 applies to this issue?