Shaking / Vibration when accelerating?

Hello Saab World!

This is my first post. I searched the forum for "shaking" and "vibration", but only found this post, which seems the opposite of my issue and the wrong forum.


Details:
I bought a 1985 Saab Turbo Sedan with a 5 Speed manual tranny. I bought this as gift in August of this year for my partner. She has always loved these cars, and after struggling with cancer I thought I would get her one and figure out what I could. I have limited resources and mechanic know-how, but I am steadfast learner and patient.

The good: the car runs, looks good and she is in love with it.

The bad: it has a ton of problems, but all of which I hope can be addressed over time with some planning.

The Issue
When you really give it some gas (like to pass a car, go up a steep hill quickly or get on the freeway (or have fun)) the front-end shakes or vibrates really bad. Basically, it doesn't feel safe. If I get up to speed and let off the gas, the shaking stops. The shaking only happens when accelerating quickly. I could coast at 70 down hill and there is no shaking. I can accelerate at low speed, no shaking.

I recently replaced:

• front passenger wheel bearing, gas shock, lower and upper ball joints and tie-end
• front driver side wheel bearing, gas shock, lower and upper ball joints and tie-end
• replaced front brake pads, and took apart, cleaned and greased the front calipers as per Sam Carlson's suggestions here: http://saabworld.net/showthread.php?t=2721 The parking brake works! (Wow that was like a two week adventure of frustration / discovery)
• got new Michelin X-Ice tires and had the car aligned

I double-checked my work and made sure all nuts were torqued to spec (using Bentley) for anything that I replaced.

My Concerns

• I'm afraid the that somehow the wheel bearings were not done right. It was my first time doing this job. (Though they feel good. The passenger side took THREE attempts. I screwed up three wheel bearings, but the third time it went on good and tight and I didn't blow out the bearing. Using the an old inner race really helps!) Although, it would seem that if this were true, it would shake all the time, not only when accelerating quickly.
• Or maybe I damaged the CV axle. I don't know how I would of done this. The axle boots look good and I know the previous owner had them replaced in the last 60k. Yet, they drive the car, so maybe that the issue.
• it's the transmission. The transmission is currently not shifting into 5th gear, pops out of reverse and is difficult to shift into 3rd and 4th. You have to be real ginger about it. (This was next on my list.)

What I do know is that when I test drove the car, it didn't shake when accelerating. This started AFTER I did the work and got new tires.

Any advice is much appreciated. I look forward to being an active member on this forum.

Thanks again!

Huh. Well no response.

I finally took my issue to a SAAB mechanic and the vibration issue during acceleration was from worn CV cups. I also found this article which isn't Saab specific, but it's pretty informative on the subject. I hope it helps others. https://axleaddict.com/auto-repair/C...n-Accelerating

I also had the transmission rebuilt which was more than I wanted to spend, but having all gears working seemed pretty essential and I didn't have the time or experience to take that on. Moving on to some electrical issues and an newly discovered leak that is allowing water into the backseat and trunk. Fun times.

I am sorry nobody replied to your original post but then Classic 900s are not terribly common any more. It is over 30 years since I last owned one and it was far too young to have suffered any of the problems you have encountered, which is why I didn't respond. Electrical issues on the 900 are relatively easy to rectify as it doesn't have the computers that frustrate troubleshooting in later cars.

For the water leak, if you have a sun roof, look at the drains, they emerge behind the rear wheels, and there is a possibility that a pipe has split.

Quote:

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Originally Posted by GeoffR

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For the water leak, if you have a sun roof, look at the drains, they emerge behind the rear wheels, and there is a possibility that a pipe has split.

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Thanks Geoff! I understand these cars are old, yet they are so fun to drive! Thanks for the tip on the sun roof drain pipes. I will look into that and let you know if it was the issue.

Thanks again!