2017 AT clunk/jerk downshifting

My money is on the slipjoint jumping, do to either improper lube or hydraulic- lock-up(no relief hole, slipjoint becomes pressurized).

 

Open a case guys. These jerk offs need to see this a wide spread problem and hopefully decide to do something about it. I'm in the process of working with an attorney too, to review my documented complaints to see if I have any other options or recourse.

 

I'm no "geargead" but a friend of mine suggested that this could be associated with the problem. It's called "spring wrap"

 

I believe that's part of it.

 

So, what can be done to fix this? New leafs? Especially if it doesn't occur all the time? Curious minds want to know......if I can do a simple fix, I will do it.

 

I have a 17 DCSB OR 4x4 AT and have the same issue. I notice it inconsistently, only upon braking at my first or second stop on a cold engine. It seems to be only once and on a cold engine, not every time. My 08 accord did something similar and I was told its a characteristic of the vehicle. Drove it for 60k miles without issue fwiw.

 

I had the same exact issue. Once they filled it up at cold temp mine was fixed. I know the guy that filled mine though so he didn't rush it. It was about a qt low. If they don't wait till its cold it will still be messed up.

 

yup, same here - doesn't happen all the time but when it does it's always when slowing fairly rapidly and always happens as the needle hits 20km/h.

saturday i noticed the same thing but less extreme just after coming to a complete stop - was moving slowly through heavy stop and go traffic, foot on the break, foot off the break to move a few feet (kms didn't even register on the needle), foot back on the break and 'thunk' a 1/2 second after stopping.

friend said it sounds like it's coming from the diff... no idea myself

 

Been happening in Tacomas for years. Search "axle wrap" in the forums, you'll get lots of hits. Happens on mine, usually when cold coming to a stop on a slight incline.

You'll be told it's normal.

 

Ditto here. No pattern yet and it doesn't happen often.

 

Mine has the same problem. After tranny fluid topped off I heard it a few time and never again. Keeping my fingers cross. I'm still resolving the buzz issue with Toyota.

 

It actually is a pretty common problem and has been posted about many times here in the forum. If you search "clunk in rear" or "harsh downshift" and "axle wrap" you will find the discussion in many areas here. Just click on the box under the search function that says "search this forum only" and you'll narrow it down to all of the turd gen complaints about this issue. Try searching a variety of search terms each time, just like I typed above.

 

I know I'm going to look into it

 

My 2017 does it when in "D" slowing down for a stop sign of red-light usually within 5 mins of starting up. It seems like it's the engagement of the transmission during downshifts. I'm guessing downshift from 5th to 2nd or 1st. I have since started driving around in "S4" around town and whenever I get in the truck as a matter of course. This has all but eliminated the clunk during braking. Happend maybe once last month. If I need to go above 40mph, I'll run around in "S5"

I don't think it is solely related to axle wrap but may be inducing axle wrap as a function of the harsh engagement of the powertrain during downshifts. If you throw it in "N" and do the same thing, it won't happen. It's so predictable for me when I leave work, I know the Stop sign it will occur at.

If you stop quickly, it doesn't happen as I think the downshifting of the transmission is possibly disabled. It happens when you stop at a reasonable deceleration rate, very little body dip to the front. If you roll up to a stop trying to use the brakes as little as possible, it is less frequent.

Which brings me to something that always bothered me. The truck is always downshifting (engine braking) like you would in a manual if you wanted to not use the brakes. Essentially in what other manufacturers would call "Tow-Haul Mode" as opposed to the tranny disengaging during braking. It seems like this constant downshift during braking (RPMs rise for each downshift) would work counter to the overall goal of fuel economy. Tacos seem to be in half of "Tow-Haul mode" and need the ECT to be activated to be full "Tow-Haul"


J

 

Can you video it happening?

 

My transmission was a full quart low on transmission fluid. I did the manual check and refilled it to the proper level. The dash rattle is coming from the tweeter grill rubbing against the pillar. This can be fixed by removing the grill and trimming or you can use some velcro tape/foam insulation and wedge it in there. Both work just fine. I found that the rattle used to appear when it was cold out and as the truck warmed up it went away. With the fix it doesn't make any noise under any conditions now.

I will admit I expect a lot from a vehicle and the little things annoy me.

Things fixed so far include:
- Rattle from the roof/headliner where the crawl control/sunglass holder is. I fixed it by tearing it apart and insulating all the wires and points where metal could possibly touch something and make a noise
- Filled rear diff to proper level it was 1.6 quarts low.
- Filled front diff to proper level it was 1 quart low.
- Flushed out transfer case and swapped in a LF synthetic... it was filled properly
- Did a drain and fill on the transmission. Found it 1 quart low after manually checking. Filled to proper level with a synthetic fluid
- Fixed the howling noise from the LCA arms with plugs from Lowes. I capped all the holes and drilled 1/4" holes in the caps at the lowest point so they could drain if there was any fluid in there.
- Greased the 2 zerks on the driveline that I have they; they needed 3 pumps before they started purging.
- Tightened U-Bolts as they were loose.
- Drained the oil, changed to a magnetic gold plug and used the Lexus/Toyota aluminum oil housing to replace the cheap plastic one.

 

My truck does the same thing....

 

Got the same issue, when cold. 31k miles transmission was checked twice.

 

ill see if i can

 

It's axle wrap. Common on many trucks. My progressive rear leaf springs fixed it.