steering vibration at 55

[jaky cakes]

any steering/suspension guru's around??
just bought a 1998 saab 93 soft top for the wife. the car is in very good overall condition and came with 4 new tyres (budget brand). when driving the car and accelerating upto motorway speeds - all seems well but a slight vibration around 70 - 80.
But when coasting along around 55mph the steering gets very light and wobbles violenty. I've stripped and lubed the brake calipers and replaced the warped discs (0.45mm RO) and new pads. I had the wheels rebalanced (around 5 grams out each side) at a good tyre fitters with a recently calibrated balancer.
from what i can tell all the steering/suspension bushes seem in good condition, and there seems very little, if any wear in the steering box.
the wheel bearings have minimal play.
whats next to check? it's doing my head in and spoiling an otherwise very good car - for a non toyota!!!

[darkdezigns]

seen this kind of thing before may very well be the cheapo tyres

[Predictable Bob]

I had a similar problem years ago with a Cortina - the cure was to have the wheels balanced ON the car ......

[jaky cakes]

I had a similar problem years ago with a Cortina - the cure was to have the wheels balanced ON the car ......

how does that work then??
or do i feel my leg being pulled?

[Scorpion]

Had the same(ish) problem with the Surf, had the wheels balanced etc but still had the wobble. Evidently one of the front wheels must have been slightly warped/ bent/ buckled or whatever, because when I swopped the front and back wheels over the wobble disappeared!

(By the way, someone on here told me to swop them over, I'm just passing on old advice.)

[jaky cakes]

Had the same(ish) problem with the Surf, had the wheels balanced etc but still had the wobble. Evidently one of the front wheels must have been slightly warped/ bent/ buckled or whatever, because when I swopped the front and back wheels over the wobble disappeared!

(By the way, someone on here told me to swop them over, I'm just passing on old advice.)

Thanks for that - I'll give it a go in the morning - tis too dark and i'm too drunk to be trusted with a wheel brace at the moment!!

[Predictable Bob]

how does that work then??
or do i feel my leg being pulled?

Nah - dead straight (this time)

From what I recall it was something to do with their being a significant imbalance in some of the other components (Late '70's Ford quality control ???) and by balancing the wheels on the car they were able to get round it.

But it'd be cheaper and quicker to try swapping the wheels around first

[jaky cakes]

Had the same(ish) problem with the Surf, had the wheels balanced etc but still had the wobble. Evidently one of the front wheels must have been slightly warped/ bent/ buckled or whatever, because when I swopped the front and back wheels over the wobble disappeared!

(By the way, someone on here told me to swop them over, I'm just passing on old advice.)

Thanks to all for advice and words of wisdom.

now sorted out. swapped wheels back to fronts on one side at a time, which vastly improved the situation. when mounting the wheels i took the time to wire brush and dress the hub/wheel mounting faces. found the centre mounting spigot on the alloys was a sloppy fit on the drive hub boss, by about 1mm. I wrapped a few turns of sparky tape around the boss to ensure the alloy was held centrally prior to nipping up wheel bolts. hey presto wobble gone!! happy bunny again and the wife's dead impressed with my magical mechanical prowess!!