168mm vs 188mm (Small vs Medium) case differentials?
 

What is the advantage of going with medium case over small case?

Take a look at metricmechanic.com, lots of info on diffs. Just checked out their new site, dig a little, there is ton of good info across the board and there are alot of very helpful forum members.

Different ratios, better fuel economy OR better acceleration. Medium cases are built a little beefier, handle more power good if you plan on doing an engine swap or going FI.

Ahhh I see. So all I would need for one of those is the new differential and some E30 CV axles?

And shim the rear ABS sensors.

Does the '95 have ABS sensors?

Yes.

So what do you guys mean by shim? Just grind down?

The reason they need to be shimmed is because the e30 halfshafts have larger diameter ABS tone rings. The teeth on the tone rings pass by the ABS sensors which are magnetic and generate a pulse. It works exactly the same way the speed and cam sensors work. If you don't shim the ABS sensors, the ABS tone rings will rub and destroy the sensors. All you need is a washer with a 5/8" hole to raise the sensors about 1/8th of an inch.

http://www.318ti.org/forum/showpost....9&postcount=75

btw, you probably don't have to cut them like I did, just drill a hole where the bolts go through.

And they still work?

Not sure I understand what you mean, but yeah they still work.

http://i198.photobucket.com/albums/a...z318ti/abs.jpg
http://i198.photobucket.com/albums/a...ti/absshim.jpg
See the "toothed" ring on the axle? That's the ABS tone ring. It's larger than the one on the 318ti axle. Therefore, if you force it into the trailing arm, it will destroy the ABS sensors if they're not shimmed. The sensors mount in a hole on the trailing arms and the magnets ride about 1/32nd of an inch above the tone rings.

Just to clarify, you DO NOT grind the sensors. You want to do the exact opposite and raise them. That's what shim means.

AHH! So I just need a spacer of sorts? I can do that. Just a decent sized washer?

This may sound stupid, but I don't need a left and a right cv axle do I? You just buy 2 and flip the other one around?

Same part number for both halfshafts. Just make sure they are from an ABS equipped e30. Early models didn't come with ABS, therefore they're missing ABS tone rings. Also, scroll back up to my previous post. I switched the picture with a drawing I made a while back. Should be easier to understand.

I highly recommend rebuilding the halfshafts with new boots and fresh grease. I bought my rebuild kits from pelicanparts and they were fairly inexpensive. Figure these halfshafts are coming off of a really old car and they probably have dry/cracked cv boots and nasty old grease. Whatever you do, DO NOT BUY AFTERMARKET HALFSHAFTS from your local auto parts store or anywhere else for that matter. They're garbage. Only use Genuine BMW halfshafts. The boot kits come with crimp clamps which require a special set of crimp clamp pliers. Do not use hose clamps or zip ties.

Here's how I rebuilt mine:
http://www.318ti.org/forum/showpost....&postcount=433

Note that I reassembled them incorectly the first time, so I had to take them apart and reasseble them again:
http://i198.photobucket.com/albums/a...ti/correct.jpg
http://i198.photobucket.com/albums/a.../incorrect.jpg

Jess as always, the Ti wikipedia and willing to help.