Another 70 mph steering issue

[stuartb]

Bought a 96 Bongo Friendee SGL5 camper conversion in June, and we just returned from a journey from Yorkshire to Burgundy and the Loire in France.

Before we went, Boris (nick for our Bongo) had a pair of tires replaced and balanced and steering aligned (supposedly) and all levels checked.

We found that as you go over 65 mph and gradually getting more noticeable, the steering gets lighter and lighter in the straight ahead position, as you steer left or right, it firms slightly so isn't so intimidating. At lower speeds, there was some bump steer which I solved by rotating the tires front to back. Add bump steer to the lighter steering at speed and it was quite uncomfortable. Thank goodness French motorways are comparatively smooth!

I have looked at varios threads here and it's not the commonly reported vibration. In Canada where I live most of the year, we are asked when buying replacement wheels whether the hub is "hub centric" or "lug centric". I.e. does the hole and hub protrusion or do the lug nuts centre the wheels respectively. Most Japanese cars I have dealt with seem to be lug centric, which eliminates the hub hole size problem. Anyway, this isn't Boris problem, he just goes vague.

The most likely causes that I can think of are incorrect toe in/out setting or insufficient castor.

Looking for thoughts before taking it in for another alignment.

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What a magnificent catastrophe you've got there. Is it yours? - Boris Badenov

[Bob]

Hi, welcome to BF.

Is Boris on original steels, and do you have the same size tyres all round?

Original spec is slightly narrower on the front and they shouldn't be put on the blunt end, but many use 4 the same, no prolem with that.

[stuartb]

Yup, Boris has same all around and original steels. Not right, but we cant afford new tires just yet. Although I suspect that would make for normal straight ahead steering and vagueness when turning. Kind of like driving with summer tyres on snow. (I change between wider profile summer tires and narrower winter tires every year on my Scooby Forester in Canada)

[Bonneville]

The most likely causes that I can think of are incorrect toe in/out setting or insufficient castor.

It sounds like toe-out but not likely to be castor unless something is worn. I wonder if the alignment people lacked settings and set it as a FWD vehicle rather than RWD?
Are your tyres wearing evenly? What make are they and what pressure? I recall changing a front left on a car for the spare once; the original was a concrete remould and the spare was a Yokohama. The result was a car that turned left on it's own. Tyre quality can have a significant effect on how it tracks.

[teenmal]

Do you know what the setting were used to check/adjust the alignment?, its always worthwhile checking the tightness of the rack, ball joints steering rod Universal Joints etc. Are you using second hand tyres on the vehicle?.

Take care.

[stuartb]

TIRES 2 new Arrowspeed (now on front) 2 existing Nexan (now on rear)

Don't know about the specs used to check alignment. I will get the correct toe info and ask them what they used.

Rotating the tires reduced bump steer.

I shall know more tomorrow!