4kq Shudder

[Zain Horning]

Hello all,
    I have an 85 4kq that has progressively been developing a mystery
"shudder".  Each morning when I begin my 60mi commute to school, the car
will ride down the road nicely.  After about 15-20mi though, I'll start
to feel a slight shake...  usually between 60 and 80MPH.  Sometimes, it
appears to be coming from the front end (in the steering wheel) and
other times it feels like it's coming from the rear of the car (in the
seat).  Occasionally, the shake will go away and then come back again a
few miles down the road.
    I originally suspected that some hard grease in one of the CV-joints
might be causing this, so I cleaned and re-greased every joint in the
the car (including the driveshaft ends).  This seemed to help, but it
did not cure the problem.  During the last 25k mi I have also replaced
the following suspension parts:

4 new Boge struts
All subframe bushings
All control arm bushings
1 rear driveshaft cv joint
1 front and 1 rear inner cvjoint
Both engine mounts
2 transmission/differential mounts
All ball joints
Front outer tie-rod ends and both rear tie-rods
All wheel bearings
I personally balanced all 4 wheels at a friend's shop (new pirelli
p4000's)

I don't think that there are too may things left that commonly wear out
:-)!  While balancing the wheels, I noticed that 1-2 of the wheels had a
slight wobble, but I think that it's negligible.    There is also a
noticeable amount of play in the transmission and differential flanges,
but from past experience, I'd guess that it's probably not a cause for
concern.  If anyone has any ideas on what could be causing this, I'd
appreciate the input.

Thanks in advance, Zain Horning
<horninza at alfred.edu>