Odd Thing Happening To My Truck

[Gunner]

Hey Guys

Got an interesting issue with my F250 (But not a big one). When I turn to the left and hit the breaks, I get a vibration from under my truck. It doesn't happen when I turn to the right, but it DOES happen when I'm pulling my trailer, and get on the breaks real hard.

Tomorrow I'm going to have new tires put on my truck, as well as have the breaks looked at, and possibly turned (I have four wheel discs on my truck). Does anybody else have any ideas as to what might cause this, and preventative measures?

Thanks In Advance

Gunner

 

[mrfixit]

Radius arm bushings? Tie rod? Wheel bearings would apply more when the brakes AREN'T applied, but maybe Loose nut behind the wheel?

 

[Gunner]

Radius arm bushings? Tie rod? Wheel bearings would apply more when the brakes AREN'T applied, but maybe Loose nut behind the wheel?

The thing is it drives like a champ, corners like a champ. It's just when I get on the breaks.

And no, the nut behind the wheel is just as tight as it ever was

Gunner

 

[andym]

It's not going to be the brakes, or it would happen all the time, although it's a good idea to have them checked out periodically.

Sounds like something is worn out under the front end. What year is your truck?

 

[6L PWR]

It's not going to be the brakes, or it would happen all the time

HUH? It wouldn't happen only when applying the brakes??

 

[bowtiehatr]

do you have a limited slip? maybe you need to add some additive to the gear oil. have had several doing this.

 

[Gunner]

It's not going to be the brakes, or it would happen all the time, although it's a good idea to have them checked out periodically.

Sounds like something is worn out under the front end. What year is your truck?

2006 F250 Diesel...............Here's the thing. If something was worn, wouldn't the symptons happen weither I was on the brakes or not?

The only way I can reproduce the symptoms without my trailer on the truck is to hit the brakes going around a left hand corner, and it doesn't even happen all the time then..........

Now, if I have my trailer on my truck, and I REALLY honk on the brakes, then I can get it to happen.

I don't think it's the ABS. If it was, I'd get that all the time, one would think.

I asked the mechnaic at the shop when I got my oil changes and my radiatior flushed, and he suspected a warped disk (which would make sense).

I was just wondering if anybody else had this happen, and what other possible causes this could be.

Gunner

 

[bowtiehatr]

now it is starting to sound like a rotor is warped.

 

[Gunner]

do you have a limited slip? maybe you need to add some additive to the gear oil. have had several doing this.

Yeah, but why would it do it when only when I'm on the brakes in a left hand turn?

But thats something I haven't thought of. Will look into it.

Thanks man

Gunner

 

[bowtiehatr]

the discs in the carrier are grabbing/binding because the oil is not slick enough and will actually try to "lock" the axles up on low speed manuvers.

 

[andym]

HUH? It wouldn't happen only when applying the brakes??

Sorry, I thought it was obvious what I meant from what the original post said about it only happening while braking to the left and not to the right.

The symptoms don't fit a warped rotor. I think there is a worn suspension bushing. Leaf springs, right? Maybe a track bar bushing?

 

[mrfixit]

That's why I was thinking radius arm bushing, til I saw it was an 'o6. Seems mighty new to be wearing out rubbers already. Then again, that's what they said about ME 30 plus years ago...

 

[Blue Goose]

That's why I was thinking radius arm bushing, til I saw it was an 'o6. Seems mighty new to be wearing out rubbers already. Then again, that's what they said about ME 30 plus years ago...

And he'll be here all week folks, with two shows on Saturday!!!

 

[blacksnapon]

Lots of things can be happening at the same time. Turning left, weight is on the inside of the left front, and the outside of the right front (any abnormal wear at these areas?). When braking, even more weight is on the front tires. When turning, any play in the bearings will make braking an adventure. The play will allow the rotors to "deflect", magnifying any minor imperfections in the rotor(s).

 

[Gunner]

Lots of things can be happening at the same time. Turning left, weight is on the inside of the left front, and the outside of the right front (any abnormal wear at these areas?). )

No, nothing abnormal, not even tire wear. I'm getting the tires REPLACED, but just for mileage, not due to abnoral wear, or anything like that. I could probably get another 5 to 10K out of the tires before I acutally had to change them..........

When braking, even more weight is on the front tires. When turning, any play in the bearings will make braking an adventure. The play will allow the rotors to "deflect", magnifying any minor imperfections in the rotor(s).

Ok, but why just to the LEFT, and not to the RIGHT? I'm thinking warped rotors, but, because I haven't seen anything else odd, worn, or out of place, I just can't say that there is anything else wrong with the truck. It doesn't even do it ALL the time, just occasionally, like the brakes are pulsing or something..............It's just damned odd.

Gunner

 

[blacksnapon]

No, nothing abnormal, not even tire wear. I'm getting the tires REPLACED, but just for mileage, not due to abnoral wear, or anything like that. I could probably get another 5 to 10K out of the tires before I acutally had to change them..........



Ok, but why just to the LEFT, and not to the RIGHT? I'm thinking warped rotors, but, because I haven't seen anything else odd, worn, or out of place, I just can't say that there is anything else wrong with the truck. It doesn't even do it ALL the time, just occasionally, like the brakes are pulsing or something..............It's just damned odd.

Gunner

Say for instance one bad rotor (caused by a sticking caliper), or one loose bearing.

 

[mrfixit]

Some of that Arkansas stupidity contaminated his caliper/fluid?

 

[Gunner]

Some of that Arkansas stupidity contaminated his caliper/fluid?

Very possible

Gunner

 

[Gunner]

Say for instance one bad rotor (caused by a sticking caliper), or one loose bearing.

Thats what I was thinking too, but I went by the dealer today, and they said the brakes look good. Don't know what to think now...........

Gunner

 

[mrfixit]

Check out this tsb:
FORD:
2003-2006 Expedition
2004-2005 Excursion, Explorer Sport Trac
2004-2006 Escape, Explorer, F-150, F-Super Duty, RangerLINCOLN:
2003-2006 Navigator
2006 Mark LTMERCURY:
2004-2006 Mountaineer
2005-2006 Mariner

ISSUE:

Some vehicles may exhibit a tire/wheel vibration caused by excessive runout.
ACTION:

The following procedure should be used if normal diagnostics lead to a potential runout issue. The procedure is intended to assist with the diagnosis of tire/wheel assembly runout and/or force variation issues. To diagnose and correct the concern, refer to the following Service Procedure.

NOTE:FOLLOW THIS TSB PROCEDURE ONLY IF THERE ARE NO SPECIFIC TSBs/SSMs RELEASED FOR THE VEHICLE SYMPTOM BEING EXPERIENCED.
GENERAL INFORMATION



NOTE:MEASUREMENTS ARE TO BE COMPLETED ON THE BALANCER AND NOT ON VEHICLE.

NOTE:A DIAL INDICATOR IS TO BE USED IF A HUNTER GSP9700 BALANCER IS NOT AVAILABLE.
ROAD FORCE



Hunter Engineering has developed a service balancer line (GSP9700) that includes an assembly uniformity feature that they call "Road Force". This Hunter system measures the assemblies loaded runout, measures the tires radial spring rate and then converts the runout into pounds of Road Force. The value that the machine displays is a reasonably close equivalent of the R1H (see below) from a force machine. The term "Road Force measurement" has been trademarked and registered by Hunter Engineering. FORCE VARIATION



The industry standard for a tire's or an assembly's uniformity is expressed as "force variation". Force variation is the variation in the load at the footprint while the inflated tire is rolled at low speed against an instrumented drum at a fixed deflection and also at a predetermined load. Ford Motor Company has specifications for force variation that all tire suppliers must meet. The information that is output from a "Force" machine is usually Radial Force Variation (RFV), Radial First Harmonic (R1H), Radial Second Harmonic (R2H), etc. These are the total variation (RFV), the once per revolution (R1H), and the twice per revolution (R2H), variation, respectively, in the radial load at the footprint. SERVICE PROCEDURE

1. Measure the assembly runout, or R1H Road Force, and mark the magnitude (Road Force reading if using the Hunter GSP9700; amount of runout if using a dial indicator) and location on the tire. As the assembly is reworked, the value and location on the tire are important.
   1. If using a Hunter GSP9700 balancer, the following road force values are effective guidelines for acceptable assembly runout:
      • F-150/Expedition/Navigator/Mark LT - Road Force of 25 lbs (11 kg) or less (check with tire pressure at normal level on P metric tires; check with tire pressure at normal level or 50 psi (345 kPa), whichever is lower, on LT type tires)
      • F-Super Duty/Excursion - Road Force of 35 lbs (16 kg) or less (check with tire at 50 psi (345 kPa))
      • Escape/Mariner - Road Force of 18 lbs (8 kg) or less (check with tire at 30 psi (207 kPa))
      • Explorer/Mountaineer/Sport Trac/Ranger - Road Force of 25 lbs (11 kg)or less (check with tire at 35 psi (241 kPa)
      NOTE:AFTER TESTING ROAD FORCE AT THE TIRE PRESSURES RECOMMENDED ABOVE, ENSURE TIRE PRESSURE IS RESET TO PRESSURE INDICATED ON VEHICLE LABEL. IF THE TIRE PRESSURE IS NOT RESET, IT MAY LEAD TO ROUGH RIDE, STEERING WHEEL OSCILLATION, OR OTHER ISSUES.
2. If assembly runout (or Road Force) is high, evaluate effect of re-indexing the tire and wheel.
   1. Mark the tire at the valve stem. This is to reference the original indexing location.
   2. Deflate the tire and break down both beads from the wheel. Rotate the tire 180 degrees on the rim, rather than following the Hunter GSP9700 balancer's routine for indexing (see note).
      NOTE:THE HUNTER GSP9700 TIRE WHEEL MATCHING ROUTINE WORKS WELL WHEN THE "TIRE ON" WHEEL RUNOUT MEASUREMENTS ARE GOOD. ON MANY MODERN WHEEL DESIGNS THIS "TIRE ON" WHEEL MEASUREMENT MAY NOT BE A GOOD APPROXIMATION OF THE "TIRE OFF" WHEEL MEASUREMENTS. THIS IS ESPECIALLY TRUE FOR THE STEEL WHEELS WITH CHROME CLADDING, AND ALSO FOR THE "FULL FACE" STEEL WHEELS. THEREFORE IT IS MORE RELIABLE TO USE 180 DEGREE ROTATION IN THE FIRST STEP, AND THEN FOLLOW THESE GUIDELINES.
   3. Re-inflate the tire to the measurement pressure and measure the assembly runout again.
   4. Mark this second high spot of runout on the tire.
      NOTE:IF THE RUNOUT GOES DOWN SIGNIFICANTLY, THEN THE ORIGINAL TIRE WHEEL ASSEMBLY INDEXING WAS NOT OPTIMIZED.
3. Review the following guidelines, based on the outcome of the second assembly runout (or Road Force) measurement.
   1. If the second measurement is still over the guidelines and it is also close to the first one, (that is the two measurements are within about four inches on the tire) then the root cause is probably the tire (Figure 1). To be SURE that it is the tire causing the high runout, you must have the two runout measurements over the guideline, and they must be in about the same location on the tire's sidewall. In other words, the high spot followed the tire when you turned it on the rim.
      
      
      
      
      Figure 1 - Article 05-26-24
   2. If the second high spot is still high and it is within four inches of being opposite the first high spot (Figure 2), then you may have a high runout wheel. In other words, the high spot followed the wheel. Dismount the tire and put the bare wheel back on the balancer. Measure the wheel runout on the bead seat surfaces with the tire off. Check the service manual for wheel runout guidelines.
      
      
      
      
      Figure 2 - Article 05-26-24
   3. If the second high spot did not follow either the tire or the wheel (Figure 3), AND the runout is still over the guideline, then you can probably improve the assembly by another one quarter turn. Draw an arrow on the tire sidewall from the second high spot toward the first high spot, and turn the tire 90 degrees in that direction. It is very likely that the assembly runout will drop to a lower number.
      
      
      
      
      Figure 3 - Article 05-26-24

OTHER APPLICABLE ARTICLES:

703300
WARRANTY STATUS:

Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
DEALER CODING

BASIC PART NO.CONDITION CODEALBALd9