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    Suspension Problem... PLEASE HELP!

    Here is the problem:
    Whenever the car is going strait or making a right turn, even if it is a slight one, the whole bottom of the car vibrates. And i' mnot talking about an annoying little vibration... i'm talking about my car sounding like an prop. airplane. Now like i said the vibration is always there, and is always bad, but it only gets worse as i turn to the right. Dont get me wrong though, the car doesnt not shake, it jsut vibrates. However, when i turn to the left, jsut slightly, most of the vibrating goes away. Depending on how much to the left i turn, sometimes all of the vibrating goes away. Also... the vibration begins at about 20 or 30mph, and when i am at low speeds, applying the brake also makes most of the vibrating go away.

    Like i said, i knwo nothing about suspension. If you guys could possibley gimme a clue on whats goin on that would be great. Also, i was planning on upgrading my suspension later down the line, but now that i'm here i might as well do it all now. I dont know if my problem is jsut bushings or hub bearings or whatnot. I know that my front shocks are bad, but i dont think that would cause vibrating. Also, the right side of the car seems to be slightly lower BUT its so slight that it honstly may just be all in my mind. If anyone was wondering the car has a very very sligth pull to the right. But that only happens if i let go of the steering wheel for longer then 20 sec. OK this is long... so please let me know what you think. Thanks, Dave
    E30 Dinan Turbo


    #2
    Some suggestions:

    When was the last time you checked your wheel bolt torque ?
    One time when I was on track, my front left wheel botls worked loose and whenever I took a left turn the car would vibrate and make a violent propeler like thumping noise. Right turns made this go away for most part.

    Wheelbearings can also cause vibration and symptoms can also mostly go away when turning in the opposite direction.

    Front control arm bushings could be worn out.

    I dont think its shock or brake related.

    Let us know when you track down the problem.

    Comment


      #3
      Haha... stupid question.
      What is a wheel bolt torque? I jsut bought my e30 about a month ago and i'm still trying to resolve some of its issues. And also, where would it be a good place to order the bushings and wheel bearings and such... what about the wheel bolt torque? Like a said man... i know nothin about suspensions.
      E30 Dinan Turbo

      Comment


        #4
        I am not sure but I think he is reffering to you lug nuts. Are those tight?
        2008 Audi S4 Avant

        Comment


          #5
          Originally posted by bimma360
          Haha... stupid question.
          What is a wheel bolt torque? I jsut bought my e30 about a month ago and i'm still trying to resolve some of its issues. And also, where would it be a good place to order the bushings and wheel bearings and such... what about the wheel bolt torque? Like a said man... i know nothin about suspensions.
          Wheel bolts = lug nuts.

          Most BMW dont use lug nuts. In a wheelbolt, the lug nut and wheel stud are combined.

          Wheelbolt torque - the level of tightness of the wheelbolt against the wheel. Usually measured in foot / pounds. I torque my wheelbolts to 80ft/lbs.

          A good place for spre parts would be BMP Design - www.bmpd.com

          Well you have come to the right place to learn about E30s. Congrats on the new car.

          Comment


            #6
            Ok... got it... wheel bolts. Yeah they're tight. Thanks fro the help guys.... if anyone else thinks of other stuff while this post is up... let me know. And as far as bmp goes.... are they really the best place to go.... when a friend of mine ordered a body kit from them it took him 3 months to get the full kit.
            E30 Dinan Turbo

            Comment


              #7
              Originally posted by bimma360
              Haha... stupid question.
              No such thing my friend. You should know that by the time you by a car. Especially when buying a car! :D

              Comment


                #8
                The recommended torque for the wheels is 82 pounds. This would be true for either bolts or nuts.

                One recommendation that I can make is to change over to studs and nuts. BMP sells both the studs and either steel or alloy nuts. It really makes changing wheels, etc so much easier. Also, the seem to be less likely to work loose, which is why most racers running E30's seem to be doing the swap out.

                Just my 2 cents.


                Jeff B.
                Roanoke, VA
                '89 325i 4 door track car (SpecE30 prepared)
                -00 328Ci daily driver
                Jeff B.
                Roanoke, VA
                1989 325i Track/Race prepared
                2000 328Ci Daily Driver
                1989 325i being restored
                1987 325is being stripped for parts

                Comment


                  #9
                  Originally posted by JeffBij
                  The recommended torque for the wheels is 82 pounds. This would be true for either bolts or nuts.

                  One recommendation that I can make is to change over to studs and nuts. BMP sells both the studs and either steel or alloy nuts. It really makes changing wheels, etc so much easier. Also, the seem to be less likely to work loose, which is why most racers running E30's seem to be doing the swap out.

                  Just my 2 cents.


                  Jeff B.
                  Roanoke, VA
                  '89 325i 4 door track car (SpecE30 prepared)
                  -00 328Ci daily driver
                  Recommended torque is 100Nm +/- 10Nm, or 74+/- 7 ft.lb. Most torque wrenches are +/- 3% accurate though. I use 80 ft-lb.

                  Try BMA autoparts, BMPD is a pain to deal with IMHO.
                  Check out my website for mail order links, info, etc.

                  Comment


                    #10
                    Franz,

                    Supposedly, a couple of years ago, BMW began recommending 82 pounds, especially for track use. At least that was what I was told by some very knowledgeable pros, all of who are well respected BMWSCCA racers.

                    As for BMPD, I've never had a problem with them. Over the last year, I probably have had 15 or 20 orders through them with the only issue of a VDO gauge sensor on backorder.

                    Again, just my two cents worth.

                    Jeff B.
                    Roanoke, VA
                    '89 325i 4 door track car (SpecE30 prepared)
                    -00 328Ci daily driver
                    Jeff B.
                    Roanoke, VA
                    1989 325i Track/Race prepared
                    2000 328Ci Daily Driver
                    1989 325i being restored
                    1987 325is being stripped for parts

                    Comment


                      #11
                      thanks!

                      Comment


                        #12
                        ok you guys are startin to worry me with all this wheel bolt talk.... I see how that may be the problem, but if i had all four wheels off last weekend and put them back on and made sure they're tight, i'm fine. Right? I mean i didnt' actually measure the torque on each bolt, bot i know its tight. Is that fine? Knowing that, I don't think my problem is with the wheel bolts. But what do you guys think..... ohhh, also when i intially took the wheels off the bolts where so tight on there i had the hardest time getting them off.... and the problem was there even before that.
                        E30 Dinan Turbo

                        Comment


                          #13
                          1st thing: If your bolts are tight and your getting the vibration at lower speeds, i.e. 20 to 30 mph, then the problem is probably not there.

                          Have you tried jacking up the car and just rotating the wheel by hand. It is possible that one rotor is badly warped. You should be able to tell by hand rotating the wheel and see if it begins binding.

                          Also, have the wheel bearings checked. While I agree with TAITO that this is probably not the problem.

                          Does the vibration seem to be coming from the front or rear? If coming from the rear, check the shock tower mounts in the rear. Are the tight and in good shape? Also take a good look at the half shafts and the differential mount. Make sure there doesn't seem to be any play or damage to the half shafts where they attach to the diff. Also is the diff still bolted firmly to the chassis?

                          If it seems to be coming from the center of the car, have the drive shaft mounting points checked. If the bearings are worn out, the vibration could be from the shaft bouncing around. Also check the transmission mount and the guibo (the rubber donut a the front of the transmission). The guibo will wear out easily.

                          If it is in the front, it could be the struts/springs or the control arms, although worn control arm bushings would probably not vibrate the car badly. Also look at the engine mounts. On the E30's, especially '87 and earlier, the right side mount is prone to failure and the engine could be bouncing a little.

                          Last, are the wheels and tires good. A bent wheel or flat spot in the tire could easily cause the vibration. In fact, I would check them first. If you have a friend with another E30 that would let you swap tires briefly it could prove worth the effort.

                          As for bolts or studs and nuts, just make sure they are tight. You can pick up a torque wrench at some discount tool places for about $20 to $30 on sale. Be careful not to over tighten, especially the bolts. With alloy wheels, you can cause damage easily. If you need to replace the bolts, I would consider switching to studs at that time.

                          One word of caution with the bolts. Some aftermarket wheels, such as Kosei K1's, have proven notorious for having the bolts (and stud/nuts) work loose under hard driving, such as on the track. I general concensus is that the paint which ends up under the shoulder of the bolt or nut, doesn't allow enough friction to keep it tight. So check the torque often.

                          Well, that's my rant for the evening. Good Luck and let us know what you find out.

                          Jeff B.
                          Roanoke, VA
                          '89 325i 4 door track car (SpecE30 prepared)
                          '00 328Ci daily driver
                          Jeff B.
                          Roanoke, VA
                          1989 325i Track/Race prepared
                          2000 328Ci Daily Driver
                          1989 325i being restored
                          1987 325is being stripped for parts

                          Comment


                            #14
                            Can't rotors warp from overtorqueing wheel bolts?

                            Comment


                              #15
                              Don't hold me to it, but I don't think overtorquing would cause the rotors to warp since any uneven pressure would be in the hub area of the rotor, not toward the outside where most warping would occur. It is possible, I suppose, that you could bend/damage the hub itself.

                              Over torquing is more likely to bend the wheel or damage the bolt holes in the wheel itself. Both of which would cause some interesting rolling characteristics.

                              Jeff B.
                              Roanoke, VA
                              '89 325i 4 door track car (SpecE30 prepared)
                              '00 328Ci daily driver
                              Jeff B.
                              Roanoke, VA
                              1989 325i Track/Race prepared
                              2000 328Ci Daily Driver
                              1989 325i being restored
                              1987 325is being stripped for parts

                              Comment

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