Hello,

This is my first post so I hope I can explain this appropriately:

I have a 2007 FX4 Supercab with a 5.4 that I bought used in March 2012. It had no issues when I purchased it and did not develop issues for roughly a year after purchase. As the truck had street tires on the 20" stock rims, I purchased new Cooper Discoverer AT3s in the Fall of 2012. Roughly a year later, I started having a vibration at highway speeds (55-70 mph) coming from the brake pedal and the steering wheel. It started as a slight vibration that I attributed to a rough highway. It progressively got worse and then started to vibrate upon braking as well, quite excessively. At that time, I needed new brake equipment anyways and so I installed new rotors on the front and new pads all around. This alleviated some brake dust problems and squeaky brakes but did nothing to solve the vibration. I figured it might be a balancing issue and took it in a couple times to have the tires balanced and this did not solve the problem.

Fed up with it, I took it to my local mechanic about a month ago (March 2014) who is very reputable and has always been fair and reasonable. He inspected the suspension, bearings, u-joints, brakes, and was unable to find the problem. He found no warped discs or blatant issues that could cause this vibration. Now, I ask you all for advice. I have found issues to many unique problems on this site so thank you all in advance. I plan to take it to my ford dealer for an oil change soon and may as well have them look at this at the same time, but I want to have some knowledge and background on this issue first. I DO NOT want to pay them to re-inspect all of these things that I have had done recently and I want to be able to point them in a direction that might be the solution.

Background: I live in Iowa and the temperature range here does not significantly affect this problem. In the winter and spring, I often engage 4x4 when hunting/fishing, etc. but I can't pinpoint any off-road driving to the start of this issue. I do not beat my truck or drive it too hard, in my opinion. I have recently had the tires rotated and this did not change the symptoms.

Any advice would be most appreciated!

Thanks!
Adam

 

Quick question? Were the tires load balanced? Did you do an alignment as well? If the vibration is worse under braking, I'd start pinpoint there. If the vibration is felt through the steering wheel, then you are having issues up front. If rotating tires did not solve the problem, do you have the ability to swap tires/rims? Maybe a friend with an F150? I know others have had issues with bent axles, but I'm not sure this is the case here. Is the issue present in 2WD and 4WD?

 

Thanks for the response R1Jester. To my knowledge, the tires were not load balanced and I have not had an alignment done. The truck drives straight, so I'm not sure if an alignment would be necessary but you probably know better than I. I don't really have an opportunity to swap with anybody. The problem is present in both 2WD and 4WD. Thanks again.

 

I always have alignment checked when I buy new tires. The dealer should be able to check it for nothing. If one is required, then it is only about $60 right now. Good luck!

 

I have noticed that the braking vibration is much more prevelant at approx. 35 mph. When slowing down from 70mph to a stop, the vibration is much more violent slowing in the 40-30 mph range than any other speed. Would it make sense that something is vibrating and this speed meets the resonant frequency of my truck...likewise producing more voilent vibration in that range? If it was alignment or warped rotors, wouldn't it vibrate throughout the entire braking application without a dependency on speed? This would make me lean toward a drive shaft problem...any thoughts anybody?

 

If you are confident there are not warped rotors, and can attribute to the fact that it happens during braking and during driving (just more pronounced during breaking) then I would focus on the rotational aspect of the front of the vehicle. Not having tires load balanced is a ? for me, as it is possible to have a bad set of tires. I've never used Coopers, but maybe search to see if there is an issue with them. The odd part to me is that it didn't happen right away as it seemed to start a year after installing tires. Did you do anything at this time to or with the truck? Offroading? Did you check to make sure all the wheel weights were on the rims, I've heard of those coming off, although Im not sure how big of a vibration effect this would impart.