Somewhere in the foggy corners of my memory there was something about reinforcing/replacement of the rear shock towers. One of mine would make Mickey Mouse look like Edison. If anyone can point me in the right direction, I would be grateful.
Are you talking about shock mount bushings? Short-lived rear shock upper mounts has been an issue for any number of BMW's, but I wouldn't know specifics if E31's have had issues with mounts, weak shocktowers, (those being the part of the body housing/surrounding the shocks and where they mount), or some-such other issue(s). Replacing the shock towers typically would be major body work, cutting out the old, welding in new, and precise placement kinda critical so the rear shocks could fit back in their proper placement. The deterioration & rusting-out of rear shock towers might be more typical on a rust-belt bimmer 30-40 yrs. old, generally.
Like garrison said normally a issue with the towers is from weak shocks bashing and damaging the towers. The other is rust that eats the towers away. I have not heard of any E31 having a issue with the towers so far.
It seems to be pretty common on e31's. The driver's side has already been boogered up. I don't know if the metal is thin or what, but where the top of the shock bolts to the top shock mount it seems to break... A lot... From what I remember, it does require body work on the inner wheelhouse which is where the shock bolts up. Seems like there are special replacements because BMW knows there is an issue. I remember seeing pictures of the mounts, I just can't remember where. On another note, is there somewhere a cheat sheet that translates wire colors in schematics to english i.e. SW is a black wire. I've been guessing at several, but there are still a bunch I can't find. Any ideas would be helpful.
No index in the manuals you have? Eek - see if there's an index in the 8'er etm's here: http://wedophones.com/BMWManualsLead.htm
Also - http://www.ecstuning.com/BMW-E31-850i-/ES69772/ and:http://blog.fcpeuro.com/2014/06/17/bmw-rear-shock-mounts/ Forgot to add, if black is SW, thats probably short for schwarz, which is German for black - of course you still need a legend, even if you were German it would be too much to guess which colors go with multi-colored wires.
Here is a link to a good write up on BMW wiring colors. http://www.bimmerforums.com/forum/showthread.php?1890991-Color-coding-for-schematics
The one on the driver's side apparently broke out the original bolt holes so they rotated 90 degrees and drilled two new holes. Bottom line, I have to take the car to a body shop, weld in a new shock mount to make it right. Both shocks have destroyed top boots. Whatever happened, the shock mounts must have taken a beating. The reinforcements may help the passenger's side. The ecs tuning parts are what I've seen before, I just couldn't remember where. Thanks gentlemen. Finally, a wire color code rosetta stone. Thank you both again.