Weird clunk, while stopped, at stop light.

2008 taco Prerunner 57k miles. 4.0 Auto trans.

Sorry for the length of this post. Bare with me.

After a heavy braking situation, to a complete stop. Ex: coming up to a red light too fast and having to suddenly stop, not necessarily " slamming" the brakes but applying them more than a normal situation.

After I've come to a complete stop, about 30 seconds later it literally feels like some one rear ends my truck. The first time it happened I about had a heart attack.

After experiencing this about 8-10 times now since I bought the truck 2 months ago. I have been trying to narrow it down to figure out what makes it do this. I am not lifting off of the brake pedal at all, it's not like it's a brake shoe grabbing and jarring letting loose as I let pressure off. It's almost as if the transmission is taking a long time to drop into 1st and when it does finally get into first it surges the truck forward. It seems that it happens more when the A/C is on, but the a/c is on more often than not, so it may not have anything to do with it.

The only other thing I have noticed, is a few days ago, a buddy came up along side of me at about 30mph and gave the look, so we both hit the gas pedal (first time I've really put the pedal down in this truck) he took off quickly and pulled ahead of me, while my truck took a good 4-6 seconds to decide which gear it wanted to be in.

I guess what I'm asking is, first does the surge/clunk sound like a possible transmission problem? Second, are the auto transmissions normally crappy and slow like this, or does this relate to my other problem?

 

I think its the AC compressor kicking on. Mine dose that only when the AC is on.

 

^^^^^^^^^^
Sounds like this. Try driving with the heater/ac shut off. Bet your fine.
As far as the trans goes shifting wise the trans has adaptive memory and since this is the first time you have really put your foot into it, it might have to learn that part of your driving.

 

Makes sense. The idea of A/C compressor kicking on, had crossed my mind. It is a pretty intense jolt, so I wasn't sure of I could blame it on that. I will see how it goes with the a/c off. Thanks for the input!

 

Sounds like axle wrap... especially if it happens after coming to an abupt stop. Also, check the torque on your rear spring u-bolts... should be around 73 ft lbs.

 

Another thing to look at is greasing the slip yoke on the rear drive shaft. The slip yoke will bind up, then release after you stopped. Had this on my 4 Runner, a few seconds after being stopped it felt like I got rear ended. Actually got out one time, walked behind my vehicle to see if they did hit me. Posted my problem on a forum for 4-runners, said it was common and recommended greasing. They cautioned about over greasing. I greased my slip yoke, and put in about 3-4 squirts at oil changes. Over 2 years now and haven't had the problem since.
Ron W.

 

Let me add, the A/C kicking on does kick the vehicle but not as harsh as that slip yoke.
Ron W.

 

Ditto.

Axle wrap combined with the AX cycling on and off.
Lift/drop blocks will make the axle wrap worse.

 

Not sure of the terms used "36/36" As far as the axle wrap, how common would that be on a bone stock truck?

 

36 month/36k mile warranty.
TSBs are not recalls and are not free out of warranty.
Some, but not all, may be covered by extended warranties... extended has not been covering the TSB for burned front turn signal lenses.

 

The stock trucks come with weak leaf springs... search "axle wrap" here and in the 2nd gen area to see just how common it is.