Violent front end shake at 50-65 mph

I'm a "car doofus", so forgive me.

I have a 94 900S with 137,000 miles. The front end shakes violently when I'm in the 50-65 mph range. At lower speeds, all seems okay (more on that later). Above 65 or so, seems okay too.

At lower speeds, it does make a "whop" sound from the front. Bad tire?

I've been told the rims are slightly bent, and that over time the problem will worsen. NOTE: It HAS been getting worse.

Could it be the rims, and now also the tires? Could it be struts?

My son checked the CV joints by driving in circles, all seems okay there.

Any ideas? I would, ideally, have something to check before I take it to a mechanic ($$$$$). The last thing I want to do is purchase new wheels and tires and then find out that the problem is, say, the struts.

Thanks,

-- Don Schenck

Reply to
Don Schenck
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"whop" meaning?

Who told you that the rims are bent, how did they arrive at that conclusion, and how did the rims get that way?

If it's true, then there is no point whatsoever in investigating further before replacing the rims. If they've been bent for a while, it's quite conceivable that driving with them like this has resulted in other damage (worn balljoints, worn strut mounts, worn steering etc).

Reply to
Grunff

in article snipped-for-privacy@lotis.uk.clara.net, Grunff at snipped-for-privacy@ixxa.com wrote on 26/11/2003 17:10:

I had a very similar violent shake throughout the entire car between 50 and

60 MPH. After successive parts replacement on the front-end (drive shafts, CV joints, boots, ball joints, brake discs, etc), it went away. I'm certain my problem was a bent drive-shaft.

I have not had to change my wheels though. If you know of a bent wheel, then that's the first place to start. If you've got a bent rim, that would indicate some abuse which may well have transmitted to the suspension and steering setup.

Paul

Reply to
Paul Halliday

Hi

I'd say it probably isn't the tires... Just put rear tires forward, and vice versa. If problem persists, it isnt. And, if it was the case, You should have had the shakes in more than a narrow speed range... Previous experience whith "the other swedish car brand" (Volvo) suggests more to

1: Tyres not balanced properly - check rims for traces balancing weights that have fallen off. (remember that balancing weights also are on the inside of the wheel) If evident that this is the case, get a new balancing act done at a tyre company.

2: Wrong front end suspension setup. - If point 1 doesn't work, its no other way: Go to the workshop and pay up. If not dealt with, You might be the one to find out just HOW safe a saab really is...

Anders Bodoe, Norway.

"Paul Halliday" skrev i melding news:BBEAA98E.B54F% snipped-for-privacy@blueyonder.co.uk...

snipped-for-privacy@ixxa.com

Reply to
AU

IME wheel imbalance more often than not does result in a speed dependant vibration. It's worst when you hit a resonant froquency of the suspension/steering.

But you just said you didn't think it was the tyres?

Reply to
Grunff

Thank you, gentlemen.

My mechanic (NOT a "SAAB" mechanic, but a great mechanic nonetheless) informed me of the bent rim about six months ago while rotating the tires.

At this point, I'll assume rims and tires as the root cause, and anything else being a result of that.

Thanks.

-- Don Schenck

Reply to
Don Schenck

If you have a 5 speed manual----you might want to check the bearing inside the transmission where the left half shaft go into the case. They wear out and need replaced. I replaced mine at about 120,000 and the vibration went away. I did the tire, half shaft, wheel bearing, tie rod end thing, and the vibration remained between 50 and 70. After 70 MPH the vibration would go away. Bent rims will vibrate at all speeds not just betwewen 50 and 65.

Reply to
Norm

Sorry Norm, but that just isn't true. In the same way as an out of balance wheel will cause vibrations at certain resonant frequencies, so will a bent rim.

Reply to
Grunff

Reply to
Norm

Reply to
WASYL ZADOROZNY

Bent rims are out of round out of true, out of balance etc.

Listen to Grunff. He knows where of...

Merry Christmas and may the New Year bring you all lots of great Saab miles

Malcolm Mason

Reply to
Malcolm Mason

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