Vibration, shaking and tires feel like going flat

[oldcarnut]

Was driving the 70 Chally when I felt a little vibration leading into a shimmying like a tire was going flat or tread separation.  Was about 55mph  Got worse very shortly and it was as if all the tires were going flat and a sensation of driving on a dried out dirt road with cracks.  Pulled over and found nothing.  Started off again and went back to normal.  Went about 5 more miles and almost at work and I could feel it starting again.  On the way home back to normal then out of the blue started back up.  Once again, came to a stop and problem went away for the rest of the trip home.  Was doing around 45-50 but once it starts it stays until after a complete stop. Putting the car in neutral while at speed made no difference with engine speed going to idle.  Just a weird sensation almost a shaking. Things I do know:  motor mount drv side is weak,  experience a clunk sometimes in tranny at shift,  u-joints seem ok,  axle plays are ok and bearings felt ok a while back when hand turning tire. Didn't really feel much unusual when both wheels turned by hand on jack stands.  Had the wife shift from park to D to R back and forth while I looked at the rear and the transition did not seem too smooth at all. Almost like the gear teeth were binding Reckon I need to pull the pumpkin and check but was wondering if any other ideas/experiences could be offered.

[Chryco Psycho]

Check the tires carefully , I have seen bulges & steps in the tread , BFJunks tires perhaps , they are bad .

[b5blue]

I had a front drum brake shoe de-laminate one time. A chunk let go first and I got a pull/drag briefly then the darn wheel locked up! Check your front wheel bearings also. 

[Ghoste]

When you describe a shimmy, are you meaning the car is shimmying or the steering wheel is doing it in your hand?

[oldcarnut]

When you describe a shimmy, are you meaning the car is shimmying or the steering wheel is doing it in your hand?

The car.  The steering wheel isn't doing it like you would get with a steering piece bad.  If you ever drove over those serrations that are put on the side of the highway to let you know you were going off the road and toned it down plus a little shaking, the feeling might be similar.  The first time the console lid was up and you could see it moving the lid.  I did drop the driveshaft today and the u-joints were ok.  With the axle up on stands and free from the driveshaft,  I turned the tires and it doesn't seem quite right so this weekend I'll pull the chunk out. Maybe its tranferring right up the drive train. The front discs and rear brakes were all looked at last couple weeks.  I'll also replace the tranny mount and left side engine mount.  It's just odd that after coming to a stop and then driving off again its gone until it decides at random to show up .  The longer it drives and faster the worse it will get making it neccessary to pull off the road then wallla--gone.

[Paul G]

I would pry and wiggle and take a good look at all the steering linkage, just because you say it comes and goes. Also, torque converter bolts, and the pulleys on the front of the engine, mainly the pulley on the damper.

[Chryco Psycho]

is it changing as it heats up ?

[oldcarnut]

I believe its already up to running temp 190-210 when it does it.  Maybe 10 or so miles out from start. Seemed to start it when I got going around 50ish give or take. Just started this issue last two times out in it going to work and not before.  Also I can run it at the same speed initially after I stop and not experience the problem.  Im following the brum brum brum thread too for possibilities.  The tires are GY Eagles

[matrout76]

sounds like a brake is dragging to me.

As you drive the car, the drum or rotor starts heating up.  You probably have un-even pad material deposited on the drum/rotor and that is causing the vibration.

Do you have one of the IR temperature guns like this:  http://www.harborfreight.com/non-contact-laser-thermometer-96451.html

the next time it does it, go around to each of the brakes and take their temperature.  if you have one that is hot, there is your problem.  you might be able to put your hand close to the drum/rotor and be able to tell a difference.

If thats not the problem, i'd look at front wheel bearings (first) and rear outer axle bearings (second).  One could be getting hot enough to start wanting to sieze and cause the vibrations. 

[Back N Black]

I had a problem that was similar to yours, it was a brake caliper not fully releasing and causing the rotor to heat up and warp which caused a vibration.

[oldcarnut]

Did a little more investigation and found a few things of which several had mentioned.  After pulling the driveshaft I could feel a very light catch in the rear ujoint but it didn't seem like much but I changed out both anyway--grease was plenty in them.  With the driveshaft off and both wheels and drums, the rear end and axles turned very easy with no noticeable issues so I haven't bothered to pull it--just added oil as it was low.  Drums barely had a catch to them pulling them of to check the brakes shoes--all looked ok.  Tranny mount was ok.  I found about a 2" long section of the inner front drivers tire edge that had the steel wires showing resulting from bad alignment.  The one thing that has changed this whole time was I installed was a new mstr cylinder and brake lines.  I'm going to pull it off to make sure I don't have the booster rod adjusted out too far in case it's not releasing all the fluid at once.  I checked the TC bolts and they were tight.   Today I looked for a tire replacement and I was taken back by how much tires have gone up lately and the unavailability of 235 - 255- 60/15 sizes.  Guess I better pick some up for the bird clone before I cant get them anymore.  Tire shop said the Obama admin. raised the import taxes/fees on imported tires thinking it would make American tires more competing but when the imports drove their prices up to compensate, the US tire mfgs. just raised theirs too.  Anyway I'm hoping one of these will have corrected the issue but have to get two tires first and go for a drive to see.

[randy73]

Check the obvious first, lugs are tight and look to see if you lost a wheel weight.  I lost a weight once and it drove me crazy trying to figure out what was wrong.