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whitecoat · 11-09-2013, 06:58 PM

Has anyone experienced a DEATH WOBBLE? I have a 30 ft 2011 Coachmen Mirada F53 chassis motorhome purchased in August 2012 as a new RV having 2000 dealer miles on it. I've had a few Death Wobbles over the last year in which I've traveled about 8000 miles. Normally the RV drives smoothly, although it shuttters some when going over rough surfaces. Now that we've had this death defying experience, I find myself constantly steering around possible road bumps, kinda like slalom skiing, but not all can be avoided.

When it occurs, the wobble is extremely violent. It starts when traveling 55-65 mph and you go over a bump like a bridge expansion joint. The wobble quickly builds and within 1-2 seconds it is so violent you can hardly hold on to the steering wheel. Try Googling "Death Wobble" to see a video someone took in a Ford pickup; it's much worse with a box on the chassis. Steering control is lost other than traveling straight. The only thing to do is apply the brakes and come to a stop. The wobble is like a natural frequency harmonic that remains at peak intensity until speed < 5 mph. It is a harrowing experience.

The RV dealer points to Ford. The local Ford truck dealer initially replaced front shocks and front tires under warranty, but now with more wobbles they have thrown their hands up and resisted any further warranty claim. I would think that other RVs, especially longer ones, would have had this problem as well. This is a safety issue that needs to be addressed, plus I'd like to drive in peace and with confidence. My wife and I will no long drive this RV until the problem is solved. Does anyone have any suggestions?

vsheetz · 11-09-2013, 07:23 PM

Jeeps can have issues with death wobble so I am familiar. It's something loose or worn in the front suspension. Take it to a good front end guy.

TeJay · 11-09-2013, 07:36 PM

I have experienced this on a much older vehicle. It has been discussed here before and I'm sure others will chime in before long.

I have 35 years experience teaching mechanics at the HS school level. I also worked on alignments, steering and suspension so I do come with some background. However I don't have all the answers and don't pretend to. There are others who have worked on HD vehicles which I didn't. This much I do know. There are reasons why your vehicle is doing this and it can be controlled or completely stopped. We drove a 1999 F-53 chassis for 10 years and never had this problem. Our latest coach is a 2014 on the same chassis with no problems.

Some will suggest that a steering dampener of some sorts can control this. That is basically a shock absorber that can control this movement. Steer-Safe uses springs to also do the same as well as controlling steering in the event of a front tire blow-out. These items will help to control the steering but I wouldn't go there until everything else is checked. They would be kind of like a band-aid fix. I drove my coaches many miles before adding any of these things and it never did the DW so I'm thinking there's something else to correct.

I don't know who you used to check this but if they threw their hands up I wouldn't go back. I would find a good alignment shop that works on larger rigs even semi's. They will likely be better able to check every steering component for wear. You may have one or more worn tie-rods that would lead to this type of issue.

Once all steering components are checked and worn ones replaced then an alignment would be needed. You can not perform an alignment until all worn steering components are replaced. Not having sufficient positive caster can lead to this. Positive caster means that the top pivot point of the front wheels (king pins) are leaning towards the rear. This places more of the vehicles weight down forcing the wheels to track straight ahead. The extra weight would reduce the ability of the DW to begin. If they know what they are doing they should be able to help with this.

Good luck with this and keep us informed
TeJay

whitecoat · 11-09-2013, 10:15 PM

To TeJay,
Thanx for your suggestions. I've seen other postings on the Death Wobble, but those are all on older vehicles. My RV is nearly brand new w/o wear and so I consider this to be a warranty issue. Note also that I keep tire pressure at the recommended 100 psi. The first wobble (in fact 3 on the trip) occurred with about 2500 total miles on the vehicle, and then 6 instances at 8000 mi milage. A little more detail on my actions to remedy:

After the first repair (new shocks and tires, altho not aligned) I actually drove for 5500 mi before I again got the wobble. However, 5 weeks ago it happened at the beginning of a trip, so we returned home (actually, on that short round trip it reoccurred 6 times in 100 miles).

My RV dealer, who has been sympathetic, had me go to a truck tire shop who did an inspection. They said the front end was tight but the new front tires had "cupping" wear, which was more than they'd expect after the limited miles driven since the new tires were put on. The alignment was significantly off (L & R front toe was +5/16 on each side vs +1/32 spec; L & R caster was left as-is for better stability at +6 deg vs +2 spec). After re-alignment, since all rear tires had good even wear, two of them were rotated to the front.

Last week I've returned from an 1800 mile trip. While the RV drove well most of the way, I had 3 other instances when the wobble started but I terminated it by quickly applying brakes. It seems that the recent tire rotation and re-alignment helped enough to temper the early wobble enough until I could apply brakes, which would have shifted weight to the front end, serving to attenuate the onslaught of the violent wobble. But, overall, the vehicle is still on the edge. I now have an appt next week at another Ford truck dealer who will do another inspection.

Thanx again for your advise. I'll post the results from my upcoming inspection. Needless to say, that first Ford shop that I went to is history for both me and the RV dealer whose had enough of him as well.

Bay37QSB · 11-09-2013, 10:16 PM

We have a 2009 37 foot Tiffin on a Ford F53 chassis and when new it would like to wag it's tail in side winds and when trucks would pass. I had a rear trak bar installed and it made all the difference in the world. The coach is actually a joy to drive now with the trak bar and a 5 Star tuner installed for extra power.

YZF571 · 11-09-2013, 10:47 PM

Although my unit is older I too had it, I mean to the point it scared the heck out of me. My RV only had 12400 miles on it the first time I experienced it. I took it in and had the front end aligned, they shimmed it, put these big bronze shims in between the axle and the frame it looks like. Anyway, I had that done and tires put on at the same time, hasn't done it since (8K). I would take it to a truck front end shop, at least that's what I did. Best of luck to you, I know first hand how terrifying it can be.

whitecoat · 11-10-2013, 10:59 AM

In reply to Bay37QSB, thanx for relaying your experience. However, my wobble is strictly in the front end. The rear is fine. This is my first motorhome. Generally when driving, its a real pleasure; we love the view out the front "picture window" and height above the road. Sometimes mild surface discontinuities at hiway speeds there can be a slight shutter of the vehicle. The M/H seems to have been more susceptible to going into the Death Wobble after the front tires have worn unevenly (due to mal-alignment), initiated by a rougher surface (e.g. bridge XJ; but nothing too far out of the norm) or a couple of quick sequential bumps. Like my note last nite to TeJay, the recent re-alignment and rotating the evenly worn rear tires to the front seems to have helped, but the M/H still is susceptible.

vsheetz · 11-10-2013, 11:30 AM

Agree that your newer coach should not be experiencing death wobble. Have you contacted Ford regional/national office? Sounds like time to escalate.

Mekanic · 11-10-2013, 11:55 AM

Quote:

Originally Posted by whitecoat

Has anyone experienced a DEATH WOBBLE? I have a 30 ft 2011 Coachmen Mirada F53 chassis motorhome purchased in August 2012 as a new RV having 2000 dealer miles on it. I've had a few Death Wobbles over the last year in which I've traveled about 8000 miles. Normally the RV drives smoothly, although it shuttters some when going over rough surfaces. Now that we've had this death defying experience, I find myself constantly steering around possible road bumps, kinda like slalom skiing, but not all can be avoided.
.......
The RV dealer points to Ford. The local Ford truck dealer initially replaced front shocks and front tires under warranty, but now with more wobbles they have thrown their hands up and resisted any further warranty claim. I would think that other RVs, especially longer ones, would have had this problem as well. This is a safety issue that needs to be addressed, plus I'd like to drive in peace and with confidence. My wife and I will no long drive this RV until the problem is solved. Does anyone have any suggestions?

something MUST be loose in the front end for it to do this.
Its not just a Ford problem. Many other makes had the death wobble.
Now since you bought it new , is it still under Warranty??
Does your state have a lemon law that might light a fire under the dealer to fix it right? Resisted further warranty claim? , are claiming they fixed it??
Do not take no for a answer. Document all calls when you talk or visit the dealer. Take notes if you must. THAT really get the their attention!!.
I hope there is one place in the road local to you where you can make it have the death wobble so you can show it is NOT fixed.

whitecoat · 11-10-2013, 12:45 PM

Thanx Mekanic for your reply. Yes, it is under warranty until 30K miles or 3 years, so at this rate we still have 2 yrs to go. The lead mechanic at the first shop did drive it and the wobble luckily went right away. THe said it scared the s__t out of him. After their first service attemp (front tires & shocks) they said they did what they could do, but obviously that's not sufficient. The lemon law in CT requires 4 times to the dealer. Next week will be my 3rd time so I'm getting there, but I'd be happy if they found something and fixed it. Thanx again.

Brockx · 11-10-2013, 01:16 PM

I had a 1970 Ford LTD which I bought new. It had disc brakes on the front, which was new to Ford (1969 I think on the LTD). The car would occasionally do exactly as you describe, start shaking so violently you had to pull over and stop on the interstate. Finally found a front caliber was not releasing properly and would heat up the rotor to the point it was trying to seize.

If you ever have this happen again get out and check for a hot hub as quick as you can get it stopped.

87Rockwood · 11-10-2013, 01:26 PM

Could be loose wheel bearings or even a loose mount on the steering box.

TeJay · 11-11-2013, 07:03 AM

whitecoat,
I know this has been said before. There has to be a reason for this to happen. New or old it is usually caused by something not being within specifications. It might be tires, wheel bearing adjustment, worn or defective parts, alignment, etc, etc, etc. Yes it COULD be any one of these but you won't know until you find a shop that has a technician who knows how to diagnose. ANY part or system on any vehicle can be checked for correctness and replaced if it is not within specifications. I am always concerned when a mechanic (that's a person who does not diagnose but simply replaces parts until the problem is corrected) A technician will listen to the owner evaluate the direction of that he/she will go then start evaluating parts until something is found. When you said that the toe setting was 5/16" that's WAY OFF. It should be as you stated 1/32" for each tire or 1/16" of total toe in. And the caster was set to the higher limit and that's OK. If it is still doing the DW then something is still not right.

I'd call Ford customer service up the chain and see if they can recommend a shop that has a technician who knows what they are doing. It might help if you went to a few local truck (18-wheeler) shops and talk to the service writer or their lead alignment technician. You might find a tech that has enough experience that either he knows what to look for or can recommend a shop that has a tech (he should have some gray hair) that can give you an idea or recommend somebody or someplace. When you talk to Ford you could suggest the place and maybe they know of the shop or at least can authorize you to take it there. Talk to the tech when you find a place. Relate exactly what has been done. Ask him if he has an idea of what could cause this on a new vehicle??? Relate the answers you get to the people on these forums and maybe we can advise or suggest something.

It is very difficult locating a good diagnostic technician. Most techs today still don't diagnose but there are some out there.

Best of luck with this and please let us know how it's going. We all want to find out what the fix is going to be.

TeJay

whitecoat · 11-11-2013, 07:23 AM

Thankyou TeJay and evryone else who have replied. This is the first time I've used a website like this and I am impressed that there are so many concerned people who want to help. I do appreciate it and will let you all know what comes of my dilema.