Thunk after stopping

Does your Tacoma thunk after making a complete stop?

 

There was a TSB to fix that it has something to do with the computer and the tranny if i remember correctly. I was told when they do the gas pedal TSB they reflash the computer to fix it. My 06 PreRunner does it but im to lazy to take it in to the dealer. Just gotta make sure you are on the brake when you pull up behind someone at a red light.

 

It doesn't lurch forward. It makes a sound and you can also feel it. I don't want to pay a diagnostic fee just for them to tell me its normal.

 

axle wrap the stock leafs suck.

 

Is this really what it is? I'm not sure what axle wrap is and will replacing the stock leafs fix the issue?

 

Also it thunks with brake depressed not let off.

 

In simple terms, axle wrap occurs when the springs flex during breaking. In effect, the twisting motion of the axle causes the individual leafs to separate slightly, with the thumping sound afterwards caused by the removal of the tension on those springs accompanied by the leafs thumping back together. This usually causes no serious harm other than the noise, which can be eliminated by the replacement of the rubber pads between the leafs.

While this occurs most often when the brakes are released, it can also occur just when the brake pedal pressure is reduced just enough to release the tension on the rear axle.

 

Thanks makes a lot of sense now.

 

I think I know what you are talking about OP. We have had a few vehicles that have done that, including my dads 99 tacoma right now that we need to take to our local mechanic. My second gen didn't do it but the ones that did it was either the transmission (tacoma) or the motor mount (jeep). Interesting to see if its the leafs like ^ said. That would be three issues that lead to a similar outcome. They both did the clunk you can feel all through the car at stops and sometimes take offs.

 

Please notice I didn't say that was specifically his problem. I simply explained what axle wrap is and the common results. An internet diagnosis obviously isn't sufficient to determine the actual problem. The vehicle will have to be checked over in person to discover that.

 

found a thread on ubolts under torqued gonna try this tommorrow.

 

Debatable. If the springs flex enough during use, pinion angle and driveline angle and be adversely affected, possibly causing differential issues by leveraging bearings and affecting preload.

Driveline breakage (u-joints, for example) is also a risk.

Both of these tend to only be a concern when offroad, as the suspension will sometimes be heavily articulated and bound when wrapping occurs. Street driving is likely no worry.

Beyond that, it's annoying as fuck. Stiffer leaf springs help. Spring clamps help and are cheap. A traction bar is the 100% fix.

 

I didnt say mine or yours was eiether. I would say hope for the best case scenario but plan for the worst. Hopefully its not the tranny

 

I found something else that causes a slight bump in these trucks - fuel sloshing around in the plastic tank. As the fuel sloshes, it deforms the tank (bends it out). As the fuel reverses, the tank "pops" back in to shape. It transmits some of the energy from that "pop" into the frame. I didn't record it, but I took my old iSight cam and my MacBook Pro and rigged a temporary underbody cam to watch things. Sure enough, I could see the fuel tank flex and pop in sync with the noise.

Oh, don't get me wrong, I've got friggin' axle wrap too - it's just this is another source of fun for "name that random noise in a brand new $31k truck".

 

lol add to this list a throwout bearing noise that when the ac compressor is running and you push on the clutch the noise goes away but, when you let off of it it sounds like a diesel. oh and the climate control fan that squeaked for almost two years

my truck now makes a new noise sounds like a light grinding noise when i'm at speed on the highway and i lift my foot off of the gas or if i'm barely on it. for example if i'm going down a hill and i lift off of the throttle i hear some strange grinding noise :/ wtf happened to toyota.

not to mention that every service dept. i have been to has been loaded with ***** who act as if they don't give a flying fuck about you or your truck end rant

 

LOL. Man, after reading all the possibilities for noise, I really darn happy to say my truck doesn't make any such sound. The greatest noise is junk (change, flashlight, etc) rattling around in the various storage trays (occasionally taking vacations to other areas of the vehicle during off-road adventures).

Years ago, I had a similar problem (springs loudly thumping) in an older Ford van (previously used to haul cargo), with the openness of that van only magnifying the noise. Needless to say, I got the problem fixed as soon as I could possibly afford to do so. The solution was new rubber pads between the springs, with the van almost distractingly quiet afterwards.

 

Torque your leaf spring to axle u-bolts to 73 pounds. That is all

 

Take the basketball out of the bed

 

OH! And I forgot to add the weatherstripping "squeak" right in my GODDAMN EAR. Nnnnnngggggg. Just the right frequency to make me stabby.

New idea: For each flaw we find, Toyota can keep the warranty service. Instead, they give us back $1000 from the purchase price. Bet THAT would get their shit in gear pronto.

 

Torqued my leaf springs ubolt to 73ft lbs and the thunk is still there. I'm starting to think it's either something with the brake system or the tranny. Damn stealership wants $150 to diagnose.