Ok, so I have a problem and for the life of me I cant figure it out.

I have an 06 LR3, almost 200k on it and a few weeks ago it started to develop a bad shake during braking. A lot of wheel wobble is present and at the right break pressure full body shake. Then I began to get a squeal on the front left. So, I went and got rotors and pads, went home jacked it up and took the wheel off and pulled the caliper. I started looking at the brakes and they didn't look bad at all. At that point I noticed I had a REALLY stuck guide pin on the top. So, I got new guide pins, swapped them out and put it back together. Drove it around... Same thing. So I jacked it back up and this time noted the large amount of play in the wheel and then in the rotor and hub with it in the air. So, I ordered a new hub and swapped that out. Squeak is gone, so that is good, but the wobble and shake are still there.

I have checked all four wheels and none have any play that I can detect when jacked up. None of the rotors appear damaged, granted I have not pulled all 4 wheels off yet.

It's much worse and much more pronounced going down hill than it is on a flat surface or uphill.

What could be going on??? It's driving me nuts!!

 

How many miles are on the front ball joints and bushings? Tie rod ends? I had a severe steering wheel wobble when going 45-60 and also when braking. I also thought rotors or stuck caliper. Replaced the lower control arms and the tie rods and completely gone.

I was going to suggest caliper guide pins but since you replaced those, maybe someone can answer if the entire caliper piston could be shot/seized?

 

I think he'd know it if the piston was seized. When he put the new pads on, he would have had to push the pistons back into the calipers. If they were extremely difficult to move or seemed frozen at that point, then I'd be worried. Otherwise, they're probably okay.

When you replaced the guide pins, I'm assuming you greased them? An easy way to tell if anything is seized on your brakes is to just go drive for a few miles with light/gentle braking, then pull over and quickly touch your rotors. If one seems much hotter than the other, you may have a problem.

The fact that it is worse when braking downhill just confirms that it is likely a problem with your front end and tends to get worse when it is loaded. You might want to just go over what you've done again to make sure things like the caliper bolts are still torqued down correctly, rotors are wearing evenly, etc. After that, I might start to look at control arms... especially the front lower controls arms. Might be worthwhile to examine tie rod ends too, but I would think that is less likely than the control arms due to the nature of the shudder you're talking about.

One more thing you could try is rotating your tires. You never know, but it could all be caused by a wheel that is bent or out of balance as well. Seems likely that this would cause vibration all the time... not just while braking, but it's always nice to rule the simple things out first by just putting your rear tires up front.

 

Thanks for the reply guys.

My main problem with the amateur mechanicing is knowing what is broken...

So, i will check the caliper again and make sure its good... But how do i check the control arms and tie rod ends?
The tie rod ends are about 3 years old at most, but could be bad i suppose. The hub bearing was fried in a big way, just not sure how to identify issues on the other stuff.

 

You'll want Bodys's brake bible. Are the rotors warped? Here is a link to it..

http://disco3. co. uk/gallery/displayimage.php?album=4184&pos=5