Announcement

Collapse
No announcement yet.

Getting a vibration - help diagnose?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Getting a vibration - help diagnose?

    Over the summer, due to bad vibrations and shuddering, I replaced my driveshaft and CSB, which were both bad and had to go. Well, a new vibration has appeared. Not nearly as bad as the ones I was having before, but just as annoying, as far as problems go.

    The vibrations I was having before were near the top of 1st and 2nd, at around 2500-3500 rpm, but they were VERY harsh, like shaking the car. The new one that's started up lately starts in 3rd at just over 2500-3500, and continues into 4th around the same rev range. I haven't had the chance (or open road) to see if it goes away after that range, but I think that it might. It also goes away if I lift off the gas a little.

    My greatest fear is that it's still the driveshaft. The one I replaced my bad one with was a used one I got from Alex, with only 111k on it, as compared to my old one which had over 220k. But I was under the impression that driveshaft vabration only came in range of about 2-3k, in 1st and 2nd, which is where 99% of people complaing of DS vibration say they're getting it.

    The Bentley manual says that one cause of vibration could be the final drive going bad (which I assume means the diff), which in my case very well could be, as my diff is getting loud and is getting close to giving up the ghost. I have a replacement for it, just haven't gotten around to changing it out. Should I replace that first, and see if maybe it cures the problem before I go investigating the driveshaft yet again?

    #2
    It could be the diff. The driveshaft isn't very likely to vibrate at that high of a speed. You could have thrown a wheel weight though when it was all icy and bumpy. Check the wheels and see if you can see where one might have fallen off.

    Comment


      #3
      Is it at a certain speed or only while accelerating?

      If it occurs at certain speeds, its likely an out of balance or bent wheel/wheels.
      Usually driveline vibrations are most pronounced while you're accelerating, which is why they are felt more in the lower gears.
      '91 318is
      sigpic

      Comment


        #4
        It mostly comes when accelerating hard around 2500-3500 in 3rd and 4th, and like I said, it goes away a little when I lift off the gas. But it very well could be speed related, because when I'm at that rev range/speed, lifting off the gas does slow me down a noticeable amount.

        I'm starting to fear it might yet again be the driveshaft, because I thought I was starting to feel vibration in 2nd a little, but who knows, it could have been the road. If it does in fact turn out to be the driveshaft again, I'm just going to say fuck it, and buy a remanufactured one. I had hoped that getting a used one with much lower miles would be alright, but I guess I'll have to see. I'm actually wondering if maybe the shaft itself lost a balancing weight. This winter has been murder on my car, the roads were bumpy as hell and shook my car around like a rag doll, when I could actually drive it.

        Comment

        Working...
        X