2006 Double Cab 2WD - Clunk (Need Help)

For starters, I’ve searched all over and am having a hard time nailing down where to start. I’ve read about the transmission mount, crossbar bolts/bracket, but I checked and all 4 of my bolts are still there.

The Issue: when I let go of the brake from a stop or even from a rolling stop I feel/hear a slight clunk from behind before accelerating. It’s not every time, I’d say 40% of the time. Transmission shifts perfect, really smooth. It feels like maybe the brakes are stuck and they’re letting go or, honestly, I was hoping that the 4 bolts under the cross member were gone because it feels like two objects clunking together upon restarting movement.

I’ve read tons of posts across all Toyota Tundra forums but can’t seem to land on a good place to start.

Suggestions? Thank you in advance.

 

Slip yoke. But I heard 2WD's don't have greasable drive shafts. Can you look and see?

 

I’ve seen a drain and fill of the transmission fix this on some trucks trucks.

 

Bad u-joint?

Sounds like it. Get under and put your hands on the shaft. Test for looseness at the spider joints on the shaft.

Have you been lubing/greasing the zerks?

 

Normalish for a 2006 with the 4.7 and the a750 tranny. My 2006 2wd drive does this too. Sometimes it feels like somebody hit you in back. There’s not really a fix for it that I’ve seen.

 

I’ll take a look, but from what I understand the 2WD’s are sealed? Is that true? Should there be zero movement?

I don’t know a whole ton about the drive lines, beyond fluids, spark plugs and belts, I haven’t done much wrenching so this is new (and intimidating) territory for me.

 

As long as I can determine that I’m not driving a ticking time bomb I’m fine with the little clunk, it’s annoying, but I can get past it.

Just want somewhere to start so I can make sure the transmission isn’t about to blow or the driveline isn’t going to fall off going down the highway.

 

It’s due for an oil change so I’m planning on draining the trans fluid and refilling at the same time, maybe that will help. Kind of hope not cause that makes me worry this transmission is on its way out?

 

It’s sealed from what I can see, I looked for the zerks I’ve found pictures of online but don’t see any?

 

Look inside the two yokes where they meet, they aren’t on the outside like normies your used to seeing

 

Your truck is probably fine. My dad use to own my 06 and he would floor the damn thing every chance he got. I hated that, because I knew someday I would own it it’s got 143,000 on it and stood up proud to his stomp sessions. How many miles are on your tundra? The factory u joints don’t have zerks, but in most cases last around 100k. Depending on your mileage I would think twice about changing the tranny fluid.

 

Ive seen trucks that are slightly low on fluid do all sorts of weird things (especially in the third gen tacoma). Doing a drain and fill gets it some fresh fluid and the proper full level. This fixed this same problem in my dads Tacoma and has been flawless since. He said it’s the best it’s ever ran

 

I suppose doing a drain and fill couldn’t hurt. But if the op truck has over 100k I personally wouldn’t flush the entire system. If your comfortable doing work on your truck and or have the time. Look online at how to service the a750. ie, checking fluid level and doing a drain and fill. Otherwise try and find a good independent Toyota tech near by.

 

I’ve lived with the clunk for almost 8 years now. I’ve read that it has something to do with the “axle wrap” when coming to a stop.

The axle wants to rotate forward when the shoes grab the drums and it rotates the pinion angle down which pulls the yoke out slightly. When you let off the brake the springs rotate the pinion angle back and you get the thunk.

The only time I really notice it is when I have to make a spirited stop on this blind exit ramp by my house. So I kinda buy that theory.

Now that I think about it, since I’ve done the add a leaf, I haven’t noticed it being as violent as it used to be.

 

Awesome explanation.

 

I had the same problem with actually what seemed liked a couple of different clunks. I changed my u joints and center bearing and added a additional u bolt on the forward part of the leaf springs.
I am now clunk free for the last year or so.

 

I don't think this is a transmission issue and I don't understand Toyota's logic in not putting zerks on the driveshaft just because it's 2WD.

 

Does your truck have the mechanical LSD? My old 2005 did something similar when leaving from a stop and turning one way or the other or going straight in low traction situations...it just needed some friction modifier added to the rest differential and it went away.

 

Will do, I’ll check tomorrow. Thank you.

That’s the plan, just drain and fill, no flushing. Previous owner did all the scheduled maintenance through Toyota, records show he kept the fluid fresh.

 

Ah, so a lift, you say? Might just have to try this route first

 

About what did it run to put in new U-joints? I'm 99.9% sure it's not the transmission, it's definitely coming from the rear of the vehicle (u-joints, leafsprings, combination thereof...).

 

Not really a lift per-se. I did the

$163 Hellwig 991 Hellwig EZ-990 Helper Spring Kit - 991

Hellwig 991 which have an adjustable shackle to tighten or loosen the spring. If I have them fully tightened, I think I get about 3/4” lift in the rear. I usually keep them backed off just a bit.

Check out the build thread here. https://www.tundras.com/threads/06-dc-daily-driver.48447/

 

The u joints were changed in my 06 and didn’t help the driveline bump.

Kind of a shot in the dark but maybe something like this would help.

 

Try putting a U bolt about on the leaf springs about 8' or so in front of the axle. Saw this posted some where, forget which forum.
Changing the center bearing helped with another clunk on my 06, no more clunks for me.