Welcome to saabscene Jonathan.

It may be worth looking at the front discs, checking them for wear and runout with a dial guage.

I find I need to balance my wheels on a fine setting to get the best results.

 

I had wheel wobble on my old '99 saloon when the discs were replaced with cheaper versions. Got replaced immediately with drilled / grooved zimmermans which I got from German and Swedish.

Another way of telling if its the discs is to slam the anchors on a bit harder at higher speed for a prolonged period or a few times and you should get brake judder / shake....

If you're not sure take it to somewhere lik Kwik fit for a free check...

 

Thankyou for your previous reply and advice.

I again took the car for wheel balancing and was very studious in that I watched the chaps spin up the wheels for any sign of buckling, to which there was none.

And also I looked on to make sure that the weights used were correct and positioned on the rims appropriately and in accordance to the equipments directions, etc.

All wheels were balanced and respun and confirmed "0 grams" required.

Changed back wheels (rear tyres are virtually new) to front and visa-versa.

In respect of brakes, have done what you suggested and hit the brakes on a number of occassions really quite hard - there is no running on that produces any kind of shake / judder etc.

Still there is this judder on the front end when accelerating....between the speeds noted in my earlier post.

I drove it quite hard last night, and this morning got on the M4 a straight and flat surface and the symptom was quite violent and more pronounced, seems the chassis shakes as does the steering.

This seems to be an odd problem, theres no banging, graunching and or crashing noises from the suspension at all and the tracking is fine also.

To confirm the suspension (which in the last year or so new struts and springs all round had been fitted) I had the car MOT'd and this was confirmed.

Do you have any thoughts etc.

I look forward to hearing from you.

Regards,

Jonathan

 

Two things, both of which have affected my vehicle.

First, stepping on the rear tyres. This is when you have uneven wear on the tread blocks, so it's like driving on a fifty pence piece. You can check it by jacking the car up, spinning the wheel and checking for fluctuations in the radius. If you've got a problem, replace the tyres.

Second, you mentioned checking the balance - was it a machine that placed weights to both sides of the wheel? Some machines don't seem to indicate whether weight should be on the inside or outside of the wheel. When it's done to both, it makes it much smoother.

 

If it only happens under load could it be an iffy driveshaft going out of line and balance?

 

Wheel bearings Had similar on one of my other motors. Wobble at particular speed. Went down the same avenues of troublshooting. In the end new bearings cured it.

 

I have had similar problems in my 130K miles 98 2.0 on and off for the last 18 months. Firstly it was 90% cured by balancing the wheels. Then it got worse again so I replaced all of the suspension with the SAAB road holding kit. The front shocks at 120K miles where totally shot, rears probably replaced before but fairly worn, front bushes shot, rear bushes seemed ok. This time the car was dramatically improved but I was still not very happy with the ride quality (or the mediocre handling even on the supposedly sport suspension). The car just never seems to feel settled, and bizarelly on smooth roads the ride quality in my track/fast road modified Porsche 944 S2 is better (50% stiffer then stock). Recently it got worse again and then failed the MoT because one of the rear transverse link bushes was worn to excess. The garage replaced it and now the car fails to track properly (always pulls to the right which is the side the bush was on), and this is despite going on a 4 wheel alignment twice. The ride quality is slightly improved but still not that fantastic. I believe I probably need to replace the other 3 bushes since they are certainly worn almost as bad as the one I needed for the MoT.
Basically as you can see on a high mileage 9-5 don't be surprised to have to change pretty much everything in the suspension to get a decent ride and eradicate shaky chassis phenomena at motorway speeds on smooth roads. Tyres are also an issue but probably only in terms of NVH. I have kuhmo on at the moment and whilst very grippy the NVH from them is awful. The car always sounds like it has a duff wheel bearing despite all 4 corners being fine.

 

I have a very slight wobble at about 75mph under constant speed, but it's always been there since I've had the car (just under 5 years). Sonce I got the car it's had the wheels replaced, several sets of tyres, new discs, and new suspension but none of them have made any difference. As it hasn't changed I've left it, but I guess it could be the bearings as they are the only thing left unchanged.

 

I too have posted regarding similar symptoms. It has driven me mad! I've had new front hub, maticulous tracking/ alignment checks, new boots all round, new disks and pads all round and played with tyre pressures. Nothing has worked.
Given that most fast traffic travels at exactly the same speed as this occurs it is all the more frustrating. It was on a run at speed that I thought this thing would come into its own, instead I have no confidence in it.
The only thing left to try is different tyre options with heavier side walls. Also perhaps the overall geometry may be out. I have wanted a saab for years and now I have one its been nothing but expense. I want to upgrade parts but am holding back because of this issue. I'll watch with interest to see if anything comes to light.
Good luck with yours

 

Just noticed that this is from 2006!!! Duh. Anyone still out there?

 

Recently had all 4 of my wheels rebalanced 1000miles after kwik-fit fitted new boots. Went to an indy tyre place, and it's totally transformed the car, no vibrations at all. All the weights were still on (ie none had fallen off), jsut all in the wrong place according to the fitter. So either kwik-fit fitter was untrained, lazy (ie just randomly stuck weights on) or their machine was not calibrated correctly. But getting the blances checked by may be a cheap starting point if you've not allready done it.

 

Just noticed that this is from 2006!!! Duh. Anyone still out there?[/b]

Yep, I'm still around! I have to admit I don't even remember my post from 2006! Anyway, since that post I've gone from 16" to 17" wheels which has transformed the car. I haven't noticed the wobble recently so I guess it's gone!