So I've been fighting a brake vibration for months now. I've replaced the front rotors and rear drums at least 2 times already. I just bought drilled and slotted rotors for the front and brand new drums for the rear. Now when I brake the shaking is coming from the rear. I just can't seem to figure it out. Any help would be appreciated!

 

I'll bet your rear drums aren't adjusted right and causing your front rotors to warp prematurely. Gotta adjust and do it all over again :-)

 

When hitting the brakes you can feel the shaking in the seat instead of the steering wheel. I'm thinking it's something in the rear or I got bad drums cause it feels just like warped drums. Any other possibilities?

 

What is the exact sequence of events?
Your brakes were working fine, then the shaking started, out of the blue?
Then you replaced the rotors and drums, and it had no effect?

Did you replace the pads and shoes at the same time?

 

Here's a trick I learned from Click and Clack years ago and has saved me thousands of bucks and a bunch of troubleshooting time. Move your front tires to the back and put your back tires on the front. See if it feels any different. A bad tire can look like brand new, or even be brand new, and still cause vibrations that you would swear were brakes or front end components. I know it only happens when you hit the brakes but I have personally had two bad tires that only acted up when I hit the brakes. I'm not going to bet money that it's a tire but it will cost you nothing to rule it out.

" Now when I brake the shaking is coming from the rear " Quote
Was it originally coming from the front? Any chance your wheels / tires changed position on your truck while you were doing the work?

You would have noticed this but I'll ask anyway. There wasn't a little axle oil on your drums when you took them off last was there? I assume the trucks are like the 3rd gen 4Runners and have the same axle seal leak issue. I just had to do the seals on my most recently acquired 4Runner. I could deal with a little oil leak but when 80W-90 gets on your brakes it will cause them to lock up at very low speed and stick-release-stick-release at higher speeds.

 

Could the rear axle bearings be a culprit??

 

And yes I replaced both pad and rotors/drums at the same time. It started happening after hauling my rzr to the mtn.

 

Have you swapped tires back to front yet?

Jack it up and shake the wheel. Put it in gear and see how much play you have in the gears. Take it for a drive to heat up the rear end parts and then immediately shoot it with an infrared thermometer and look for hot spots. Pull your rear end fill plug and check the oil. Don't tighten it back up yet. Pull your drain plug and stick something in there to hold the oil in while you examine it for excess wear metal. Those are a few ways to look for bearing problems without removing parts. Pulling your back axles to examine the bearings isn't that hard but at minimum, you'll want to have some new outer oil seals and the O-ring that goes between the axle tube end and the outer plate. You'll often damage the oil seal when you pull the axle and we're talking about maybe $15 bucks per side and easy to do. Depending on your mileage you may want to do the bearings too if you go in that deep. There is a little more to that project though.

I really think if it were the bearings you'd be hearing them all the time and not just when braking. I'm really leaning toward a bad or out of balance tire if you feel real sure you have your brakes up to snuff. Swapping back to front should rule out the possibility.