Re: <E34><E28> Thrust Arm Bushings

["Pete Read" <pete.read@xxxxxxxxxx>]

Dave Nelson asks about thrust arm bushings for his E34 M5:

>I can't seem to pin down the digest that may have had info on
>the replaceability of an E34 M5 thrust bushing, with that of a
>750IL?  Is it a perfect fit, if not is there a heavier duty one
>that is?  I've seen some chat about "cutting" down the 750IL for
>fit, but is this necessary for my car (E34)?

Dave,

I wrote a couple of notes last year about thrust arm bushings for
the E28 and E34 five series.  The first was a warning about
correctly modifying 750i bushings for E28s.  Dinan 650.962-9401
and Steve D'Gerolamo 201.262-0412 both do it correctly (see references
below to the first note which includes the correct dimensions).  I've
also included the second note with all the part numbers (see below).

The bottom line is that any E34 can use the 750i bushing (31 12 1 136
607)
without modification  -- E28s need to have the width machined down.
I also guessed that the 750i bushing would be a suitable, and much
less expensive, replacement for the E34 M5.  Since that time, I've
talked
with James Leong at Dinan and he confirmed that they have successfully
used 750i bushings with E34 M5s (James is always extremely helpful as is
everyone I've talked with at Dinan).


...old post on thrust arm bushings....

Subject: <E24><E28><E31><E32><E34> Thrust Arm Bushings, Additional Info

Several people have contacted me about my "<E28><E24> 750i Bushing
Warning (Dinan Bushings are fine)" post in bmw-digest v07.n1375
and Mformation #194, so let me add a little more detail.

Bill Shook (owner of Kraftwagen here in Northern Virginia) has
told me more than once that he appreciates BMW's effort to keep
improving parts when they find a problem area.  A good example is
the, twice updated, shift detent cover plate Bill told me about
when I was looking for oil leaks at the back of my transmission.
The old part was a pain to keep sealed properly, but the new improved
part has a built in seal that doesn't leak (cover plate 23 31 1 228 470
for E28 M5/535i, E24 M6/635i, E34 M5 and many others).

Looking at the updates to thrust arm bushings, it seems that BMW has
gone through a similar improvement process.  However, the process
has created quite a few superceded part numbers which adds to the
confusion.  I've tried to sort out the latest part numbers and
update history (see below -- all prices from 1/97 book).


1.) E31, E32, E34 Thrust Arm Bushings (56 mm wide)
- --------------------------------------------------
E32 750i, 740i   E31 850i, 840i
  31 12 1 136 607  $ 45.75

E34 M5
  31 12 2 226 528  $104.75

E34 535i, 540i, 530i
  31 12 1 139 456  $ 46.50
  31 12 1 136 606  expired 03/91
  31 12 1 133 488  expired 12/90
  31 12 1 130 587  expired 03/89

E34 525i
  31 12 1 136 605  $ 49.83


2.) E24, E28 Thrust Arm Bushings (50 mm wide)
- ----------------------------------------------
E28 M5, 535i (after 9/85), E24 M6, 633i, 635i
  31 12 9 058 819  $ 36.43
  31 12 1 126 394  expired 11/90

E28 533i, 535i (til 9/85)
  31 12 9 058 818  $ 30.98
  31 12 1 125 428  expired 01/89
  31 12 1 126 302  expired 09/86

E28 528e, 524 TD
  31 12 9 058 817  $ 47.28
  31 10 1 129 078  expired 11/88


If you look closely, you can usually find the last seven digits of the
part number on the part itself.  For example, the 750i/850i bushings
will have "1 136 607" stamped in the green plastic insert which
surrounds the center aluminum piece.

Each of the bushings above should be physically interchangeable
within their group.   That is, any of the group #1 bushings will fit
on the E31, E32, and E34 cars, while any group #2 bushing will fit
the E24 and E28 cars without modification.

The bigger engine, heavier cars have the stiffer bushings.  So the
stiffest E31, E32, E34 bushing is the 31 12 1 136 607 used on the
750i/850i, while the stiffest standard E28 bushing is the
31 12 9 058 819 used on the M5/M6/535i/635i.

As I described in my earlier post, the 31 12 1 136 607 for the
750i/850i is the high performance bushing of choice for E24/E28 cars,
but it must be properly machined to prevent interference.  You won't
find the part number on modified 750i/850i bushings because the
plastic insert with the part number is also machined.

One last note -- if I had an E34 M5 I'd be very tempted to try the
750i/850i parts when it came time to replace my bushings (less than
half the price of the M-parts).

  Pete Read
  '88 M5
  Arlington, VA

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