2012 F250 XL 4WD developed death wobble in 2016 had it to a couple of shops, eventually after researching online, I bought gas shocks and steering stabilizer, and had new tires installed on the same day, 14 months ago. That stopped the death wobble, but ever since leaving the shop that day, there is a vibration at 49-52 MPH. It started out to be sometimes then progressed to be always at that speed. I took it in after 5000 miles on the new tires, had them rebalanced and rotated. The vibration persisted. I took it to the dealer this week. He says he put it on the lift and ran it without the wheels, checked the engine mounts, checked all the u-joints, could not get it to vibrate without the wheels on. He claimed that the non-name-brand tires were cupped, and that he was sure it was causing the vibration. I said ok, put new tires on it, and throw the old ones in the back. He put on goodyear wrangler at trailrunners. I drove it home and the vibration is still there. I took the tires out, and rolled them on the garage floor, they appear to track straight and smooth. So back to the beginning. Is there any chance the gas shocks (Rancho RS5000) have a resonance to them that causes the vibration at a certain speed? What else might it be. Remember it did not vibrate like this until I put gas shocks and new tires on 14 months ago. Is it possible that it was the tires and they have damaged something else like making the brake rotors unbalanced?
Since a few shops looked at your truck, they checked the rest of the suspension?
Did they check the rims when they installed your new tires? A slightly bent rim on the inside is hard to see even for a trained eye.
Vibration at only that narrow speed range, if is not a bent wheel, just screams imbalance. Since the wheels and tires have been balanced 3 times and it is still present has me thinking brake rotors. Some are balanced by machining weight off but I have seen weights clipped on the cooling vanes. One falls off and you now have what feels like tire balance.
As a former shock absorber engineer, I have never experienced that type vibration caused by a shock absorber.
You didn’t work for Ford. I had an early 1970s Capri GT. Between 45 and 50 the front end would shake, and it got worse over time. After new tires and alignment, it got better, but didn’t go away. I was at a fraternity party after I graduated, and was complaining. One of my brothers also drove a Capri, and he had the same problem. Another worked at Ford and raced them. Both said Ford cheaped out on the struts, and that led to the front end shake. The solution was to get decent struts. I wasn’t sure about the first guy, but when a Ford engineer told me the same thing, I figured it had to be true.
Is it possible to be engine or transmission related? I am not sure of the advisability of shifting it into neutral at that speed, but it could help move it from a suspension problem.
I was not employed by Ford but I have worked ON Ford projects FOR Ford. Cars and trucks. Rancho shocks are not the best, but as I posted, I have never experienced that condition on any of the various vehicles. Not saying it doesn’t happen though.
There is balancing, and there is… balancing.
If the balancing wasn’t done on a Hunter GSP9700 machine, I would suggest that the OP go to a shop that has one of these superior devices. I–like everyone else who bought Outbacks in 2010 and 2011 had a similar problem because of the crappy OEM Continental tires–and balancing didn’t seem to help. Finally, the dealership installed a Hunter GSP9700 balancing machine, and the problem went away.
Here is a link for locating shops that use this particular Hunter equipment:
Shocks are non-structural parts and different from struts, which in addition to a shock absorbing role have a structural function. It would be unusual for a bad shock to cause a vibration, but a bad strut might. Vibrations most noticed at higher speeds are often caused by one of these
- bad tire
- wheel(s) out of balance
- wheel/tire has side to side wobble
- wheel/tire is out of round
- faulty wheel bearings
- out of balance drive shaft
- faulty u-joint
- something loose in the suspension parts (ball joints, tie rod ends, etc)
- bent axle shaft
You just have to go through each of those one by one. What I’d do w/that problem and nothing was visually obvious by poking and prodding, listening for bearing problems, etc, I’d test the tires/wheels for side to side wobble and out of round first. Next I’d put the wheels on a simple bubble balancing machine. If a shop claims a wheel is properly balanced but it is way off as measured by a simple bubble balance, something’s wrong. If nothing found yet, next I’ve move the wheels/tires to different corners, see if that made any difference. Well, you get the idea … For a vibration to occur something has to be either loose or non-symmetrical, and that’s what you are looking for.
I’m going to suggest that this vibration is due to the same phenomenon as the death rattle - an oscillation due to the suspension geometry - and that worn parts aggravate the situation and added steering dampers are more of a band-aid, than a fix.
So I don’t think it is tires. I think there is one or more worn parts that is allowing the oscillation to amplify.
Death rattles are common on solid axles with a lot of camber. Yes, 1970’s Capri’s had it, too, and it was due to the way the suspension was designed. There is a rubber bushing that wasn’t stiff enough and replacing it with nylon fixed it.
But the common thread is worn parts.