Deceleration issue - 06 V6 Automatic

My 06 Auto is showing its age with 197km on it. Let me explain this issue.

When I apply the brakes there is an obvious rumble, there is also pulsation. What I do know is I need to replace the brakes, I will most likely be doing all four corners since the rear shoes are about 20%.

But there's more to it, If I apply the brakes and let off while coasting theres a rumble in the steering wheel and floor boards, it will rumble until continue accelerating again, its mostly noticeable at lower speeds with the shifter in "Drive". It is the same in 4wd, no difference other than feeling like the truck is in 4wd. If I come to a hard stop and take off again theres a noticeable "clunk" in the driveline, im guessing theres some decent axle wrap going on

I climbed around underneath the truck, the u-joints don't seem to show any play, the differential backlash is good and the pinion isn't loose or anything.

I'm thinking its possibly a wheel bearing. I will start by doing the brakes. But if anyones had similar symptoms I would love to hear from you.

 

warped rotors?

 

this^^ is wat i say do first.

 

It is "warped" rotors, I know that much. Im wondering about the other vibrations/rumbling etc that are present when the brakes are not applied. Im going to pull the rear drive shaft tommoro and check the u-joints.

 

It is likely that a caliper is dragging/not releasing. You're looking at new rotors, pads, and new calipers. Replace them as a pair, so you have even braking.

 

I was going to say hanging caliper

 

I'd say this OR you have more than one issue. Start with the simple fix (brake pads, rotor turn or replace) as you've already looked at the drive shaft and affected components.

 

A hanging caliper will have unevenly worn pads. Inspect before you buy parts.

 

And that brake will got hot on a longer trip.

Also, check the rear leaf springs, bushings, and u-bolts. A broken leaf or loose u-bolts could give the symptoms you describe if it allows abnormal movement of the axle.

 

Sounds like front control arm bushings or ball joints. These are pretty much 80K mile wear items now-a-days.

Unlikely other options are uneven brake pad transfer (which most people think is warped rotor) or actual uneven brake rotor surface (warped rotor). This would be caused by crappy pad and rotor combination or crappy bedding.

This is a symptom seen on many vehicles, Chevy truck / Tahoe, BMW (all), Porsche, Corvette, Audi (very often) more.

Bad suspension components can allow disc (front) brakes to wear unevenly. Changing the brakes may produce a temporary remedy.

Bad wheel bearing will also create a humming noise that will change as you turn corners / bends at 30+ mph.

 

If he had suspension related complaints in addition to the symptoms he listed, yea. Still a good thing to check. I still say brakes, although I have yet to test drive it. A test drive and inspection will be the determining factors.

 

Still getting good normal fuel economy? If you have an O2 sensor out and your engine is on duty cycle, you can get that feeling when you let off.

It's a strange thought but I've had it happen in another vehicle.

 

We'll find out today, pulling it all apart. Lets hope my differential is not the culprit as ive had them fail on all Toyota vehicles I have owned, 4runner, 2 pickups and a Supra. I know for sure that the brakes are in need, which is odd because they were replaced with OEM rotors, pads and calipers 20,000km ago, so I will start with the rears.


Im going to pull the driveshaft and check for bound u-joints, there's nothing obviously wrong with them though, worth a shot. Being an automatic its hard to get it to duplicate problems.

 

Looks like the front rotors will need replacement first of all. I can't find anything decent locally, im weary of OEM now so I will have to buy online. This time slotted. Heres a question though, I noticed a decent ridge on the outer edge of the front rotors, normal, but it looks like the pads are scraping along the ridge, theres shiny spots on them.. quite possibly the "rough" sound im getting while braking.

My u-joints feel great. No binding. The slip joint has some play though, I wonder if all the years of neglect and axle wrap have caused it to wear out?


So on the topic of axle wrap, wow are these springs ever wussy, Its hard to believe how much the pinion angle changes when I switch from Drive to Reverse. They are the TSB springs, but im thinking my worn out shocks would be a major part of the problem seeing as how they are setup to work against the wrap, which if they are blown, they wont be doing. This could be what is causing the rumbling after I apply the brakes and coast, that dissapears when I accelerate. The differential itself has no issues, no play in the rear wheel bearings, everything is nice and tight that way.