The Ford F53 Death Wobble

The Ford F53 death wobble is associated with the Ford motorhome chassis that is commonly used on American RV Motorhomes.

Using the term “wobble” is trying to describe a violent oscillation of the vehicle, see video below.

E450 Death wobble

I know the link is showing the wobble on the E450, the F53 acts in the same way. This wobble should only apply to the earlier models without the additional Panhard rod. Due to the chassis having this problem, it seems that you can still find a lot of reports on the internet making you think that the newer vehicles still have a tendency to wobble.

About six years ago I was road testing a Ford F53 based motorhome, when I went over a hole in the road this sudden impact to the front axle started off as I can only describe as an oscillation, feeling like an empty supermarket trolley at speed. I applied the brakes and it stopped. This oscillation was a bit of a shock, but as they say “There’s no substitute for experience” this is very true!

I have experienced this before when road testing rear engine buses, hit a bump at 45 mph (that was flat out), hit a pothole and the front wheels would oscillate, hit the brakes and it stopped surprisingly.

A lot of things can make a vehicle such as the Ford F53 start to behave like this, some are more susceptible than others. The F53 problem stems from the long front parabolic suspension springs. What happens is they start to oscillate which then starts the steering wheel oscillatory which then transfers to the body.

Tyres

When the vehicle has been left for long periods of time without being moved flats will start to appear on the tyres. These flats will stay with the tyre for the rest of its usable life. If you jack the axles up so as the tyre is clear from the ground, then spin the wheel, you notice the gap between the tyre and the ground does not stay constant. The tyre is no longer around.
When leaving the vehicle for an extended period of time the tyres should be overinflated or the vehicle should be jacked up with the wheels clear of the ground. If the tyres are no longer around then in the right scenario this can be a contributing factor.

Tracking

Tracking can have a big effect on the oscillation problem. If the tracking toeing in, this would then have a dramatic negative effect on the oscillations. With a tracking fault and none round tyres, the oscillation process would be easier to start. Having the tracking toeing out by say ten minutes can give a positive effect.
Worn Spring Eye Bushes
Worn bushes would not help the situation but hopefully, this problem would be noted on an MOT or service.

Vehicle Weight

As I previously mentioned I had an oscillating problem on a bus. This was most certainly due to a light front axle, there were no passengers on board and the engine was situated at the rear. This can also be a contributing factor with an American RV motorhome especially if you have a motorbike fixed to a rack on the back of the motorhome. If this is the case then you need to place some of the heavier items nearer to the front.

Wheel Balance

I haven’t had any problems with motorhome wheel balancing, if the tyres are not round then this starts to give you the same effect. In the UK I have not had any of my customers complain about this problem which I find amazing, considering the state of our roads.

If you have a similar problem contact us at LAS on 01604 861999 and we will be able to help.