Brake vibration 36-20 MPH or so in rear

So i know i posted about this issue months ago, like more than 6 months ago. but there seem to be multiple threads... so i decided on a new one...


my 2019 trd OR 4x4 has had the brake shudder in the rear while slowing from 36mph or so down to about 20mph. dealer said no issues. some say it's the rear diff with some sort of out of roundness in regards to the brake drums.

well, i have an update and mine seems to be fixed, after about 400 miles of driving this weekend i can say that.

what did i do?

rotate the tires.


i kid you not.

i had the pulsating like many others have experienced right before the rotation. it was very obvious. almost every time. sometimes it wouldn't be there.

ever since, none. it's gone.

now with that said, i also changed the following at the same xact time as the rotation:

rear diff fluid
front diff fluid
transfer case
engine oil and filter

engine oil/filter has nothing to do with the issue and i can't see any of the other things causing what i was experiencing.

so it's got to be the tires. maybe there is a wear issue where after so much time the rear tires wear funny? maybe it's an alignment issue in the rear if these have an adjustable alignment and that causes something weird after so many miles? i didn't touch the air pressure btw as it was 30/31 all around before and after the rotation. and i rotated front to back staying on the same side as indicated in owners manual.

so far, zero vibes... will update if it comes back.

 

Thanks for the update. How many miles were on your truck before the rotation/fluid change?

 

i had 10,460 miles when i did all of this work:

the oil for 3rd time-
1st at 1200 miles, 2nd at 5500 miles

diffs/xfer is first time.

this is the 2nd tire rotation, first being around 5000 miles.

i complained about the vibes at 5171 miles, so right after the 1st rotation BUT i am pretty sure i had it before i did the rotation- my posts on here should show or not show that.... I need to find them.

 

https://www.tacomaworld.com/threads/2019-trdor-shaking-from-rear-when-braking.641432/page-2

is the other thread and i state back in december:

"Been doing if for at least 1000 miles maybe more and I am at 5000 miles."

so at that point, the tires had not been rotated yet. after i rotated them, it still vibrated. So i don't know. time will tell.

the rear diff was low on fluid as was the front but i can't see that causing any of this.

when i say low, it was hard to get any on finger when i checked it before i changed it. And there are/was no leaks anywhere. Now it's full.

 

I took mine in to the dealer at 500 miles because of the vibration. They told me it was 'normal' and to prove it, they let me drive another 2020 that was on the lot and it, too had the vibration. These are brand-new trucks. I can't believe this is a fluid issue.

 

me as well. but i had to mention it as i had changed it all.

 

My 2019 SR5 has had decel vibes like you are describing from about 400 miles on. They're mild, but annoying none the less. I wish that rotating the tires solved the vibrations on my truck. It didn't solve them at 5K with a rotation, and it didn't change anything after replacing the tires at 10K.

In my case I'm pretty sure that it's a driveline issue. Hopefully your vibes don't come back...

 

well in my case it's always vibrated at least half the time. sometimes it would not on one stop. but another it would. every trip, be it short or long, it would always vibrate some of the time. since the rotation i have driven it local as always and no vibes. one long trip, and no vibes. maybe low fluid in rear diff was the culprit, somehow. I can't see how unless as you are slowing the fluid moves toward front and if low, the rear is exposed but i can't see that causing a vibe but who knows. i am leaning more to funny tire wear. but she tracks straight and has 10k miles on her.

 

Appreciating all the feedback. Wasn't able to try the 4WD idea but plan to tomorrow.

 

Whatever it was that you did, I'm glad that it seems to have worked for you. I'm pretty skeptical, as you also seem to be, that the diff fluid sloshing around would cause these vibrations, especially with these vibes seemingly so consistent between different trucks, but who knows. This shouldn't be such a mystery with as many trucks as there seem to be with these issues.

The reason I'm pretty sure that my vibration is driveline related is that my vibes go away completely if I load the bed down with a 300-400 hundred pounds. This points to something being off with the drive line. I measured, and my angles are actually pretty close between the rear diff flange and the transfer case flange- they're about a half a degree off. The first and second shafts are off too. I was going to shim between the leaf springs and the axle, but it hardly seems worth it to open up that can of worms and go through all the trial and error bs people have reported. The two peice drive shaft seems to be pretty fussy to get right, and the carrier bearing would also probably need attention too, and it seems to be a pretty wimpy party to begin with. Maybe all that is easy, but I'm tempted to get a one piece drive shaft from Tom Woods. Seems like pretty expensive spaghetti to be throwing at the wall, but they have a 30 day return policy... If it doesn't fix my vibrations I can just send it back.

 

I agree that this feels driveline related. I just drove it this morning and put it in 4WD and the vibration is still there. The frustrating thing is that it vibrates even if I don't brake... I can just let it slow down to a crawl and the vibrations start. Then they disappear when I accelerate. I'd be interested to know if the Woods shaft works for you. Keep us posted if you do decide to go that route.