[Prev][Next][Index][Thread]

<E28><E24> Suspension Installation, 1a of 2

(part 1 must have been too big -- now it's 1a and 1b)

Enclosed is my E28 M5 suspension installation procedure.
It was originally posted to John R. Allen's M5/M6 M-digest 
([email protected], ftp://ftp.halcyon.com/pub/users/jrallen/BMW).

This procedure is applicable to any E28 '82-'88 five series
or '83-on E24 six series.

All E28s and '83-on E24s have the same basic suspension.  
Only the spring rates, shocks, sway bar sizes, and front 
sway bar frame mounts change.  Earlier, before '83, six series 
share suspensions with the older E12 five series.

The exception to E28s being all the same is the '82 528e.  It
has the old-style (E12) rear suspension, with the 20 degree angle
semi-trailing arms versus the newer Trac-Link 13 degree arms.
Basically five and six series are identical cars with different 
bodywork and interior trim.

So yes, you can make your 525e/533i/535i handle like an M5 by 
upgrading the springs, shocks, sway bars, and wheels.  The front
sway bar frame mounts need strengthening.  Larger M5 225/50-16 
wheels bolt right on, but the rear fender lips need to be rolled 
under for clearance.  M5s have bigger front brakes which also bolt 
on (at least TRX size 15.3 inch diameter or larger wheels are needed 
for brake clearance).  But remember, there is no substitute for the 
wonderful double overhead cam 24v motorsport engine (256 hp stock, 
294 hp with Dinan chip).

M5s have load-leveling rear shocks with larger diameter springs
than other E28s.  The load-level elimination parts listed below
are only needed by M5/M6 owners when removing load-leveling shocks.  
The parts are just normal E28 rear shock pieces needed to fit the 
standard size replacement spring and shock.

When looking at the suspension, check and consider the following 
parts for replacement.  All parts are the same with the exception 
of the sway bar rubber bushings (different diameter sway bars).

Front
- -----
Shocks, also called strut inserts
Strut bearings
Bump stops, absorbers (not needed for Bilstein front) 
Sway bar links
Sway bar rubber bushings

Rear
- ----
Shocks
Top shock mounts, guide supports
Paper gasket at top shock mounts
Bump stops, absorbers
Sway bar links, dogbones
Sway bar rubber bushings


***********************************************************
Start of M-digest post about E28 M5 Suspension Installation 
***********************************************************

My "M5 Suspension -- Part 1, Overview" post covered the 
basics of the Dinan Stage 3 suspension changes (shocks, 
springs, camber plates, and sway bars).  In "Part 2, Details" 
(real soon now), my plan is to include more details like 
calculations for springs and sway bars, natural frequency, 
alignment specs, and some additional shock absorber information.   
 
However, while removing my front sway bar the other day 
(to finally fix the inner hole problem), I realized that 
the basic installation process is also of interest.   So
I rechecked some bolt sizes and tried to write down the 
important details.  It has been a while, but I did the job 
twice.  First, installing springs and camber plates only, 
then changing shocks the second time.  Some details may be 
forgotten, but this procedure combined with the Bentley Five 
Series Manual should give a good feel for the job. 
 
 
Replacing Shocks, Springs, and Sway Bars  
- ---------------------------------------- 
Changing E28 M5 suspension pieces is a straight forward, 
time consuming, process.  There are no ball joints to pop 
or brake lines to remove.  The only special tool needed is
a spring compressor.  An electric or air powered ratchet is 
also nice for the many turns of the spring compressor and 
other bolts. 
 
Shock and spring changes are usually done together because 
the springs are mounted over the shock absorbers, both front 
and rear.  Springs have to be removed to change the shocks, 
and if the spring is changed, it's only a little more effort 
to change the shock.  If purchased, negative camber plates 
are installed along with the front spring and strut insert 
(shock).   
 
Sway bar installation is a separate task from shocks and 
springs.  It takes much less time and effort.   
 
Dinan estimates eight hours labor for the complete (Stage 3) 
job of shocks, springs, negative camber plates, and sway 
bars.  If you're not experienced, plan on more time.   
 
I usually work on one wheel at a time.  That way  there is 
an example to work from if something doesn't look right upon
reassembly.  Note that all sizes are wrench sizes, not the 
actual fastener size.  For example, a 6mm shaft diameter
bolt usually needs a 10mm wrench.  I'll just call it a 
10mm bolt. 
 
...End of part 1a of 2.  To be continued...... 


  Regards,

  Pete Read 
  '88 M5