Rear Hubs / Bearings

[kimbo]

Posted this in technical help a few days ago, with no response, so thought I'd try on here.
Hi all,
Having a few 'issues' with our 325 at the moment, and need some clarification if possible.
Just to explain what the confusion is, we're rebuilding a 325 racer, which has Porsche calipers on the back (new brackets welded to hub). Dan wanted to 'off' the handbrake mechanism, which we dont need, so we stripped the hubs down, which is when we noticed that each side had a different bearing, the right hand one being 'correct' for anything from a 318 to a 325 (according to euro car parts website, anyway) and the left hand one having the smaller bearing as fitted to 316 and, it seems, the later 3 series compact. The drive flange on this side is also thinner, but still has the same 4 stud spacing as the thicker one on the right hand side. Obviously we want to make the left hand one the same as the right hand one!! simples.

So the question is - will any 4 stud disc brake hub be 'right', or are there a gazillion different combinations?

Thanks for looking

Kim

p.s. Just to clarify, the above 'mods' were carried out before we owned the car, and are just the latest in a very long list of bodges which we are having to undo before the thing is fit to race.

[nickso]

I had this very problem a few years back, buggered if I can remember what I found out about it though. Hub, bearing and driveshaft are all different though.

In the end I went 5 stud. Still have the trailing arms etc in the shed though.

Took a pic of the hubs as no one on here believed me at the time.

[kimbo]

Thats the exact problem that we've got. Going 5 stud for us isn't really an option, as everything else is set up for 4 stud, including the uber expensive and lightweight split rim wheels. We need to get hold of a complete left hand rear corner with the correct (larger) bearing and 4 stud drive flange - but which model is the right one?? Thans the 64000 dollar question.

[Demlotcrew]

There are two different bearing sizes.

Non disk and disk.

Non Disk is 39x72x37mm
Disk is 42x75x37mm

I would say that the non disk bearing is actually larger, but the flange will be weaker.

You need a flange and bearing from a rear disk car with or without ABS.

HTH

Andrew

[kimbo]

Thanks for the replys.
Sorry to be dim, but I've got no real experience with E30's other than our own. Which models
are fitted with rear discs and 4 stud drive flanges?

We'll then need to get an entire lefthand rear corner off of one of these, as the hub carrier is different on each side of our car. Then get it modded to fit the Porsche caliper - oh good, more faffing and expense!! This car had better be good once it (finally) gets built.

Kim

[nickso]

Thats exactly what no one would believe. Both hubs are disc but different sizes. I couldn't be arsed sussing out the difference between the two. I did suspect it was ABS or non ABS though.

[kimbo]

Thats exactly what no one would believe. Both hubs are disc but different sizes. I couldn't be arsed sussing out the difference between the two. I did suspect it was ABS or non ABS though.

Thats what we seem to have, although cant be sure due to previous modification / butchery - might mean a trip down to a breakers with a measuring stick to clarify.
Kim

[nickso]

Well I think I still have both arms in the shed, If you need any measurements off them let me know.

[kimbo]

Well I think I still have both arms in the shed, If you need any measurements off them let me know.

Cheers, I'll get back to you if I do.

Kim