<e28> driveline shudder

[Pearson-Franks Family <pearsonf@xxxxxxxxxxx>]

Tom asked:

>Date: Thu, 07 Jan 1999 11:07:57 -0600
>From: Tom Jarlock <dlions@domain.elided>
>Subject: <e28 driveline shudder
>
>Upon takeoff the driveline shudders when reaching about 28 mph.  This is
>an automatic so there is no guibo.  The shudder goes away at about 33
>mph and doesn't reappear again until the next takeoff.  Any thoughts,
>suggestions?
>
>thanks
>
>Tom Jarlock
>88 535ia, 170,000
>CCA#127308

Larry babbles:

Tom (and Digest, cuz this comes up a lot), here are my experiences,
in more or less the order of likelihood in general.  I haven't had
an E28 auto, so I can't swear to it not having a guibo, so I would
encourage taking a look.  Anywho:

1)  Good, ol' u-joints.  The middle or rear u-joints can be easily
    be tested with the old twist of the wrist.  The middle one is
    obnoxious to get to, in that you have to remove the heat shield,
    so do this with the exhaust cold.  The shield can be manuvered
    out without having to drop the exhaust.
2)  Bad center bearing, or the rubber surround.  Still have to
    remove the heat shield.  You can check that the bearing is pre-
    loaded, by shifting it forward a couple of mm before tightening,
    but bad pre-loading is a pretty unlikely culprit.
3)  Unbalanced shaft itself.  Pretty likely, all and all, but try the
    easier/cheaper thoughts first!  You have to pull the two
    part shaft, taking care to center punch the two halves before you
    separate them (unless you suspect they were misaligned, already!).
    Driveline Service in Portland, OR does a good job; so do others.
    Be ready for $450ish, as I recall.
4)  Check for a guibo anyway.  If you have one, they crack.  When and
    if you get this far, replace the rear tranny seal, and on the
    5-speed, the shifter shaft seal - frequent leakers.
5)  Check rear tranny mounts - they tend to be soggy by now, and engine
    mounts - the right one in particular under the exhaust manifold
    tends to crack and seperate.
6)  Here's a good'n:  I repaired the rear subframe mounts, and cured
    the very last of the driveline shudder I had already done all the
    above to.  Go figure!

Have fun!  Larry F.

Larry Franks
Issaquah, Washington
'86 535i x 2
'83 245 GLT (Swedish iron)

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