So I recently had some front end work done (tie rods, ball joints, new hub, new rotors, steering damper, adjustable track bar) and added a bilstein leveling kit (coil springs and shocks) and some 295/75/20 ATII tires. Since I've had the work done I've noticed a few things that I need some help identifying. When I'm on the highway and hit traffic to the point where I have to slow down (10-15 mph) or stop and go, there is a noticeable wobble to the truck. I thought it might just be the stretch of highway I was on but it happens too frequently. I feel myself wobbling back and forth in the driver seat even, but as soon as I get back up to ~50 mph its back to a smooth ride.

Also, I did new front pads in the spring because they were grinding but the rotors looked to be in decent shape. When they did the front end a few months later they put new rotors on. Since then the breaks have squealed like an sob. I did o'reilly semi ceramic pads and they put on napa rotors. they still perform fine but its extremely annoying. its been a couple months and a couple thousand miles and still a bad squeal. if the truck sits for a couple hours its real bad but once they warm up they don't squeal as much.

It's a 2005 f350, any input or suggestions would be greatly appreciated.

Thanks in advance.

 

Wobble - I would lift front tires, rotate tires, and see if there is any variation in the thread surface, or if you can rotate tires front to back and see if there is a difference. I once had a belt separation and it did exactly as you describe.

As far as the brake squeal, it's the brake pads, or more precisely, the friction material.

The term ceramic is called out when potassium titanate fiber is used as a reinforcement fiber, developed as a replacement for asbestos fiber in an organic based formulation. In reality it has no place in a friction material for vehicles over 6,500 lbs, but in this case it's a marketing trick by throwing a little of PT with the standard steel wool reinforcement (aka semi-metallic) so you can call it Ceramic. Fiber reinforcement is typically 15% of the friction material component. There are a lot of "Ceramic" pads out there in the aftermarket that use a pinch of PT for the marketing when in fact it's a semi-met. PT only reinforced pads are really expensive.

 

Thanks Jack, I will look into that and see if I can find anything. I can noticeably see my truck wobbling down the road and its a strange feeling and I'm sure it looks a bit goofy too.

oreilly said there's a lifetime warranty on the pads so if i take them off and bring them in they will swap them out for new ones. They didn't squeal or make any noise on the original rotors, only after they put the new ones on. I figured the pads might take a while to mate with the new rotors but its been a few thousand miles and it hasn't changed. would it be worth it to bring them in and swap them out with a brand new pair? or see if I can get the warranty money put toward a different material pad?

Thanks again

 

It took me awhile to figure out it was a tire. Being a brake guy all problems start out as a brake problem.

As I would decelerate down from 45+ and getting around 30 I would start to feel the vehicle move to the right, then correct left, at a slowing oscillation. Since I was brake on, I started to think it was rotor thickness variation. And it would repeat over and over during all deceleration events. The rotors measured out fine, looking for 0.0005" differential every 5 degrees. Then I tried decelerating with tow-haul without braking and it returned, as did slowing without braking uphill. That's when I checked the tread, found a bump, and confirmed that was the issue by flipping tires.

I'm glad you brought up the changing rotors situation as that changes things and I didn't pick up on that reading the first post, my fault. Is it possible the rotors are not from the same manufacturer?

Here is the reason I ask. Brake noise has a huge number of contributors. The friction material is the exciter, then everything else depends on the individual parts natural frequency. You always have a certain amount of vibration, it's intensity and frequency (Hz) depends on the friction coefficient, and since friction material friction coefficient changes with temperature, you can have noise when the brakes are cold and not warm, or any temp range.

All of the vehicles parts can become the excited loudspeaker. Over the years we found pad assemblies, calipers, caliper brackets, knuckles, and even fenders that became the loudspeaker, but it's most often the rotor.

When the industry develops a brake pad assembly for a new vehicle launch, we will change the formulation, under layer, geometric shape (chamfer), noise insulator on the back of the pad, density of the friction material to eleminate brake noise. It's easier then all the other options. But when that doesn't work so well, we take a look at hard parts - brackets, calipers, rotors.

Rotors are the second most thing changed after the brake pad assembly. It's natural frequency is altered by the thickness of the two rubbing discs, the hat section stiffness, and most often the cooling vane configuration. Sometimes it's the style of the vanes, straight vane, curved vane, post vane, or the number of the vanes and their width. All will change the natural frequency of the rotor, where it has its singing sweet spot.

Rotor design is one of the most under respected or misunderstood aspects of the brake world, and in the aftermarket the companies spend no time on this aspect. Often the rotor is reversed engineered but the vanes are laid out to whatever the casting pattern they have in house.

So this is a long winded explanation of why you can have brake noise when it's been the rotors changed. The solution then becomes the tough decision. Changing to another brake pad, either by manufacturer or level within the same manufacturer is often the easiest way, and easier to convince the counter guy of the need. Or you can try a few geometric changes.

Some swear by the spray-on sticky goop on the backs but I hate those. I prefer using the opposite approached used in the OE Asian designed vehicles, using a moly reinforced silicon grease, aka Honda, Toyota, etc. Both methods try to reduce vibration transmission.

We can keep going.

A reference:

http://www.sae.org/events/bce/honeywell-liu.pdf

 

I agree with Jack about the wiggling problem. Tires will delaminate and sometimes, just enough that you can't see the defect.
Try having someone stand in front of the truck, 25' or so as you drive towards them. Same with the rear. Sometimes you'll see the tire "blip" as it rotates.
Last summer on the road, it happened to me. Originally we couldn't tell which tire it was, but a few miles later, it became very apparent.

 

I guess I should have left it as "Yep, probably the rotors".

 

Make sure the spindle nut is snug then back it off 1 notch for the cotter pin, if the rotors are warped then take them down to a machine shop or take them back ( return) also double check the rims if one is bent it would play hell on a smooth ride, tires was a great advise aswell

 

I brought it in where I had the work done and they took it for a drive, he said the tires seemed to be fine and it didn't show any symptoms of ply separation. But it happened again yesterday while I was driving to work, a better way to describe it is it feel like one of my front tires is oval, if that makes sense.


As for the brakes I'm hoping I can pull the pads off this weekend and swap them out to see if that makes a difference. If not looks like I will do rotors next week.

 

Did they put the tires and rims on the spin balance machine ? That would eliminate tires and wheels.

 

How old are the Shocks?

 

Check the track bar

 

The shocks and coil springs were done when the new tires were put on, so cant be more then 3-4 months old now. And they did not pull them off, I do have lifetime alignment through this shop and am due for an oil change in a couple weeks. I was thinking I will have them check the tires and do an alignment when I bring it in.

 

I have an adjustable track bar for the leveling kit I had them put in, would that cause an issue like that? Would could it have loosened up?

 

I'll bet it was under torqued, I've seen it happen more than once. also the track bar might not be adjusted to the proper length for the lift.