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Discussion Starter #1 (Edited)
OK - Just found I problem I didn't want. At about 60/65 MPH I hit the brakes and it starts slowing down then goes into a wild shake on the left front. Did it 3 times today coming home. 50 mph and below there is no shake and it stops straight. It feels like it is only the 1 wheel.


FYI In the past I had an issue where the RF wheel/tire went into a shake while slowing down and going around a right corner. I searched Death wobble and found shock problems, track bar problems, etc. I checked the track bar it didn't seem loose but I tightened up the track bar bolt tight enough to break it - surprise. I replaced it with a little bit larger true grade 5 bolt and got it good and tight. I also replaced the shocks with new Bilsteens that were standard to 1 1/2 longer gas charged - they seem to be a bit too long and hold the body up on the springs - gives a little wiggle until there is some weight to sack it down some. I also found at that time that the air gauge I was using - dial type- was reading at least 10 psi higher then what was in the tire. I have E rated stiff side wall tires 265/75-16 on it- they came with it. I was airing them down to 20-22 per the gauge that was actually 10-12 psi - on the road. I figured that was too low and caused the right turn wobble. I had them checked for balance - they had been run for a few thousand miles with no issue at higher pressures. Every tire was out of balance but were able to be Rebalanced OK. So I thought everything was OK.
Jeep has been parked for a couple of years while I did things to it - new Ujoints and greasible CV joint on Front Driveline, water pump, idlers, belt , etc.


Finally got it up and running again then this. The only other thing that may be an issue is that I had it up on jack stands with wheels off for that couple of years while life got in the way and the rotors rusted up some. I was going to sand them off/clean them up before running it again but I forgot and went ahead and stuck the wheels on (at night) and dropped it down. I know I probably affected the pads while they rubbed off the rust. I ran it while holding down hard on the brakes to clean them off - ran it around using the brakes hard , etc and ordered a set of new pads front & rear. Haven't installed them yet. Seemed to be stopping better and better no pull, hard pedal - push harder and stop better.



Finally getting to the questions. Would a bad unit bearing allow the wheel/disc to start shaking badly under braking only the way I described it. No shake or wobble while running up to 70mph - just when I hit the brakes at that time. Is there any way a brake pad would be slick enough to not clamp ( not wore out - still plenty of pad) and start a wobble - the other 3 wheels not reacting badly - clamping and slowing down.


Any Ideas appreciated!


LBM
 

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Sitting for periods of time is the worst thing for a vehicle.

Since it happens when you apply brakes I would start there.

The brake grabbing as you apply would cause those symptoms. a rust spot on the rotor would allow the brakes to apply unevenly. Change out the front rotors and pads. Check the calipers for freedom of movement. Bleed the brakes get some fresh fluid.
 
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Discussion Starter #3
Rotors

Sure would of been better to clean look at the rotor like I planned to - got in a hurry.



Thanks - Do the front rotors come off easily?? Any screws/bolts or ??? holding them on the hub??
LBM:frown2:



Sitting for periods of time is the worst thing for a vehicle.

Since it happens when you apply brakes I would start there.

The brake grabbing as you apply would cause those symptoms. a rust spot on the rotor would allow the brakes to apply unevenly. Change out the front rotors and pads. Check the calipers for freedom of movement. Bleed the brakes get some fresh fluid.
 

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If the suspension & steering were in A1 condition a rusted rotor would not induce death wobble because there would be no excess movement among those components. A unit bearing absolutely can cause DW, but you can test it for excess movement rather than just replacing parts. Still a good idea to start with the rotors, but have someone turn the steering wheel left/right while you watch the track bar and every steering component. Be sure to check the ball joints as well.
 

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Discussion Starter #6
183300 - I think most of it is on road miles - probably towed. One reason I bought it was because it was so clean underneath. I've put maybe 3000 miles on it most of that on the road. Until I figured out what the bad squeal was - the front drive shaft cv joint. Fixed that but then it was up on stands and things keep getting in the way and it stayed there for way too long. Found a bolt on the bottom of the front cover that had backed out and was rubbing on the lower pulley - thought that was the squeal - nope but it did tell me that someone had it apart at some time. So you just never know with used anything.:surprise:



This! How many miles on the clock?
 

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Discussion Starter #7
Definately do not have an issue running at speed on the highway until I hit the brakes then the LF starts a bad scary shimmy/wobble - that only seemed to be that wheel. I slowed down to 50-55 mph and then pushed the brakes hard to stop and there was no wobble. Probably the brakes and possibly the tire.


I have the pads for all 4 wheels and I just ordered the 4 rotors from Rock Auto. Just going to do them all while I'm there and I'll look to see what ever I can see on the rest of the components. I just checked the mileage 183300. I think most is on the highway miles - bottom of jeep does not look at all like it has been off road much. Probably with that mileage the ball joints and tie rod ends are loose????? Except for the way underinflated tires on the asphalt wobbling which was the bad gauge I haven't had any drive-able issues until now - well except for that squeeling front driveshaft CV joint that drove me nuts until I figured out it was the problem.


I paid a premium for this Rubicon because it was so clean top to bottom. Been learning Jeep Lessons I never wanted to learn ever since.






If the suspension & steering were in A1 condition a rusted rotor would not induce death wobble because there would be no excess movement among those components. A unit bearing absolutely can cause DW, but you can test it for excess movement rather than just replacing parts. Still a good idea to start with the rotors, but have someone turn the steering wheel left/right while you watch the track bar and every steering component. Be sure to check the ball joints as well.
 

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