New 4x4 Tacoma Has Vibration When Braking

Had my truck at the dealer for the 5000 service yesterday. Took my new wheels to have them installed while there. I mentioned the vibration coming from the rear and even took one of the techs for a drive. I couldnt get the truck to do much of anythjng. Very little vibration felt on test drive. Realized after I left that the weight of the 4 wheels in the bed ( less than 200lbs.) was keeping the truck from vibrating for the most part. I stopped at lowes on the way home and picked up 12 40lb bags of topsoil. I had roughly 600lbs in the bed and that eliminated the vibration. I ask some of you to try this. Take a drive after putting a couple hundred lbs in the bed and see what happens.

 

Seriously this is the truth. Weight in the back of mine and vibration was gone. It kinda makes me wonder if the brake proportioning valve is bad.

 

Load sensitivity valve???

 

Pinion angle/ axle wrap?

 

I actually put some baggage on the back and two passengers from the airport, was picking up some relatives, and the vibration was almost gone.

 

I know this won't help anyone but just sharing my experience. I have 19 TRD Pro and experienced rumble strip feeling since I had it. As I rack up the miles, now 5500, the vibration got less and less.

I have actually put it in neutral just so I can better "feel" the brake. It now brakes pretty like a normal car.

The stabilization seems to started around 4000ish. By the time I had my 5k service, I didn't even bother have dealer to look at it.

I know some of you have driven the truck much higher mileages and still have the issue, I may be the anomaly. Good luck to all.

 

Update on my case guys.

 

Which option are you choosing?

 

Thanks for the update, I know nothing is perfect but this is my 5th Toyota and the only one that's had weird qualities.
Every time I drive my wife's 2016 Prius, it handles tightly and runs so perfect, just like a Toyota really should.. and it reminds me, what the heck is going on with my new truck..

 

I will go with repurchased

 

This is all according to Toyota Rep and master mechanic:

The vibration was initially thought to have been caused by some axle flange clearance between the rear axle and the drum brake. However, I was told that later on they realized that they drum brakes were over tightened from factory. It was a simple mistake, but happened to a decent handful of Tacoma's. This caused the drum housing to overheat and warp eventually. Long story short, the hope is that the affected trucks get new drum brakes and I guess if the axle shafts need to be replaced, then so be it. But I'm not 100% the reason and issue behind the shafts themselves.

On the other hand axle wrap is caused by a slightly different problem. I'm not saying that there are no Tacoma's out there with potential for axle wrap, but the entire issue is different. Axle wrap literally feels like someone is pushing you from behind over and over again. As the rear axle twists from rotary motion, it forces the whole rear end to move up/down/front/back which creates a pushing sensation. This happens when braking AND accelerating.

The TSB mentioned in this thread is mostly affecting the truck when the driver brakes.

 

Mine has the vibration when going below 30 mph breaking or not, even if I drive on bumper to bumper traffic at that speed the vibration is constant. An engineer from toyota test drove it and he said that the axle replacement or drum wont fix it. Need to wait for a better fix.

 

Too tight meaning the shoes are rubbing on the drum causing overheating? I tried new drums and it didn't help my situation. I would.der what it is.

 

Toyota replaced your drums completely? I ask because they often attempt to only resurface them, or just change the drum shoes/pads.

 

I wonder if your vibration could be coming from the drive shaft? Either way, I'm sorry you're experiencing this.. It's the worst when they don't know the reason/fix.

 

I have no idea, mine has a bulletin to replace the axles but they said that is not going to get that problem fixed. They told me to wait for a fix for now. On the other hand if I put a lot of weight on it, the vibration goes almost away completely.

 

They replaced mine completely about a week ago, still feels weird though..

 

You know, I find it funny that the dealership just shrugs you off and tells you to wait for a fix. I mean, on one hand they're being honest by saying that the current TSB isn't effective. On the other hand, they're allowing you to continue to drive a vehicle like acts abnormal under braking.

I personally told my service rep that I don't want to drive my truck until it is safe again. After making it CLEAR to them that I don't feel safe (Honestly, i was over exaggerating) they happily gave me a loaner and worked on my truck.

So far so good. I think that Toyota should do the TSB work on your truck regardless of what they think. If it doesn't work, then fine, they're right. But what if it does alleviate the vibration?

 

My update

 

Sucks it had to go that far, 4-Runner now?