17 hours ago in Articles
The Harvey brothers dominated autocross in an obsolete Datsun a couple decades ago.
I've got a frustrating issue with my daily and I need some advise. About 3 weeks ago I was on the highway at about 60mph and the car started to vibrate pretty bad. I thought a wheel was falling off.
I pulled over and checked everything and as it looked ok, carefully started off again. No vibration.
This past weekend, I changed the front brakes and put on the winter tires. Vibration came back, I pulled over and again nothing seemed wrong so I drove away and no issues. I just had a mechanic check the car and he couldn't find anything. An hour after I left the same thing happened.
I can't reproduce the issue but I can stop it by pulling over.
Anyone have an idea? CV? Engine mount? Clutch out of balance?
Dry inner CV joint will vibrate on acceleration, settle down on coast...
No such luck. I just took it out again and have more info. It is pretty smooth right up until it starts shaking and keeps shaking right up until I almost have stopped the car. I tried pushing the clutch in and that had no effect.
And again it doesn't do it all the time, maybe about 25%.
In reply to Streetwiseguy:
Does it seem to be coming from one particular side? When it happens can you make some tight turns to the right and left and see if the frequency of the vibration changes?
Sounds like the Dodge truck or Jeep 'death wobble' . Not sure what would cause this in an FWD car, though. Maybe a combination of an out of balance or out of round wheel with some rotted out bushings? (I'd imagine the wheel would be obvious more than 25% of the time, though)
Edit - just realized that it's happening with two different sets of tires.
Start at the wheels and work inward from there. Hubs/wheel bearings, ball joints, strut tower bearings, tie rod ends, etc.
Jack the front up and get the wheels spinning. Just put it in gear and get it to 25 mph or so. My guess is you'll see a tire wobble. Intermittent wobble sounds like maybe a separating belt that gets its harmonics groove on under certain conditions.
Otherwise, any one of multiple joints (including steering rack mounts, ball joints, tie rods, etc) can make it happen as well. Our Prevost motor coaches with tag axle steering would wobble intermittently when the joints started wearing out.
Thanks for all the advice. I'll try these suggestions and update when I have more info.
Here's something that I failed to mention because I didn't connect the issues. The ABS light has been on and off for the past few weeks, my mechanic cleaned the sensor and cable and the light was off for a few days.
The ABS light came back on last night and there has been no vibrations since. The vibrations were bad yesterday before the light came on. I've put on 200 miles since last night and it's been perfect. I really hated the idea of driving it but as I got to speed, there was absolutely no vibration. These shouldn't be connected or can it be?
Yes, they can be. ABS trying to activate when it shouldn't can cause strange vibrations. Think about driving down the road with one front brake trying to engage in a rapid pulsing manner.
Are you sure you don't have a failing wheel bearing?
Yeah a loose wheel bearing can cause ABS weirdness, best checked with an indicator, they're technically junk before they get much perceptible play in them.
Further update, another 100 miles today with no shaking what so ever. Up to 65mph and it feels good again. ABS seems to be the issue. I never would have guessed this one at all.
I wouldn't have guessed it either, especially because ABS usually makes an earthquake worth of noise that I would think you could notice.
But it would explain the problem. Make sure the sensor isn't being caked up with junk because of a bad bearing (which could also cause the issue)
Just an update, I replaced both wheel bearings with built in ABS sensors and so far the issue has been resolved.
Thanks to everyone who helped on this.
Also get your instant access to the digital edition of Grassroots Motorsports Magazine!Learn More