Good write up, altough I must add some info as a professional BMW LSD builder
In my opinion the E21 lsd unit is stronger than the late E36 ("280").
Mind you that the sidebearings are sitting closer to each other on the E21. that´s an advantage.
E21 diff housing is better because it has a bigger pinion bearing, just like 2002 turbo had. Don´t forget they used this diff on the euro 323i E21.
I agree the E36 planetarys are better as they have the 23 teeth design for the friciton plates. You can put those inside the e21 lsd casing along with the proper E36 compression rings (and there are 2 versions!).
That´s what I use on big torque aplication such as modified 323i´s or so, sometimes I have to go 4 discs(75%) otherwise it will desintegrate the discs tooth, specially using the recomended/modified ramp angle.
I don´t understand why don´t you use a drift to hammer the sidebearings races out. It´s a piece of cake if you have a good quality drift punch.
The same thing for the star plate, 2 whacks and it´s out...
To put the new races in I use my big bench vice, piece of cake.
Don´t try that with a crappy or small vice, you could damage it.
Better of using a press or heat cold/heat then.
Every bolt should locked with threadlocker Loctite, specially ringear bolts, ask me how I know this
I recommend keeping everything spotless clean when reassembling.
Be very carefull with crowngear teeth, becuase a minor dent, almost invisible, will cause MAJOR rumming and you willl be crazy trying to find out what´s causing it.
Spacing shims should be cleaned with wirebrush, measure the thickness with a micrometer, specially if using the 6 bolt version(4 bolt version is a PITA to shim correctly even for me)
Every particular ratio/housing assembly has a correct pinion shim to it.
If you take a pinion/gear and install it on another housing you will be in big trouble if you don´t shim the pinion correctly.
You will be very lucky if it turns out ok.
Backlash should be checked with a dialgauge everytime!
This is most important and if too much it can break pinion teeth and make an awful mess inside your diff, account on a complete rebuild if that happens.
It´s not rocket science but you must be precise and pay attention to detail.
And now my hijack:
If you need modified ramp angles you can reach me at [email protected]
or you can find me on ebay under "carbsandparts".