Standard E30 to M3 rear axle upgrade

[irishsteve]

First post!

I have recently acquired a 1500 mile (!) E30 318 which is about to receive an S54 (when I finally source one with less than a billion miles) and an M3 body conversion.

I've been told I need to get hold of a Z3M rear axle for the increased width, 5 stud conversion, bigger bearings, bigger brakes and general increase in strength. However, it appears that used ones are now purely based in mythology and new ones are, frankly, overpriced.

Does anyone know what my alternatives are? I believe E30 M3 DTM trailing arms are worth investigating but I've no idea where to source them.

Note: I'm a total novice at any sort or car building. I hadn't used the phrase "trailing arms" until about 4 days ago. Someone is doing the work for me but sadly he won't do my shopping as well.

[martinpallot]

Z3m axles go for about 4K last time I saw one for sale and dtm axles are a double that if you can find one/havekne built

[ajay]

A Z3M rear axle is not necessary for an S54 conversion, there are plenty of E30 S54 conversions that don't use one. There are pro's & con's of using that rear axle, don't get hung up if you can't get one, a decent suitably upgraded standard rear end would be ok for a NA S54 conversion IMO.
As for the 4K price tag, i would happily accept 4K for my E30 modified Z3M rear end if anyone's willing to pay that much ( i very much doubt) a˜†.

[ross_jsy]

£4k, pull the other one Martin.

http://vi.raptor.ebaydesc.com/ws/eBayIS ... 3573834415

http://m.ebay.co.uk/itm/371818152386

http://m.ebay.co.uk/itm/98-BMW-Z3-M-Roa ... iid%253A14

Just need a left one now, should be manageable with your remaining £3,200 or so

[martinpallot]

find me the other one, two shafts and the diff to go with it and you wont be far off.

As stated, that's the price for the last complete one I saw for sale. I don't talk shite just for the sake of it.....

[irishsteve]

£4k, pull the other one Martin.

http://vi.raptor.ebaydesc.com/ws/eBayIS ... 3573834415

http://m.ebay.co.uk/itm/371818152386

http://m.ebay.co.uk/itm/98-BMW-Z3-M-Roa ... iid%253A14

Just need a left one now, should be manageable with your remaining £3,200 or so

You have some amazing Google skills. I've been at this for a week and not found a thing. So do I buy one of these and cross fingers that a matching one shows up?

[ross_jsy]

Ebay.de is your friend.

If you really must go for a z3m rear end, then yes. They come up quite frequently on either eBay.de or eBay.com. You could also buy an e30 m3 rear end for around the same amount, which will be plenty strong enough:

http://www.ebay.de/itm/Original-BMW-E30 ... Sw44BYIbMy

Translates as

Hello,

They offer here an original BMW E30 /// M3 rear axle

With brake system

Originates from a BMW E30 M3 2.3L

The rubber pads should be replaced
 

The rear axle is in a used condition as seen in the picture.

Used

Traces of use / rust are available

Or

http://www.ebay.de/itm/BMW-M3-E30-Schwi ... IJeQLXVGtw

This is original BMW M3 E30 rear axle swing.
The rear axle fits in every E30!

The rear axle swingarms are supplied with brake discs, brake calipers, brake linings, brake dust guards and handbrake cables.

There are a couple available:

http://www.ebay.de/sch/i.html?_odkw=e30 ... e&_sacat=0

Hope that helps

Ross

[jmc330i]

At those prices maybe it's time I sold my Grp N M3 stuff

[ajay]

Remember although Z3M trailing arms are technically a direct fit to any E30 they do not have brake lines run along them as all E30 trailing arms do therefore have no studs for the brake line clips or brackets on the rears of the backing plates where the hard lines (on an E30 meet the flexible hose to the calliper, all these along with custom hard lines & custom flexible calliper lines (E30 ones no good) must be added. Also the offside trailing arm strengthening bar will clash with the fuel filler (rubber filler pipe to the fuel tank) when the vehicle suspension is compressed, all require addressing before the trailing arms "work" on an E30.

[martinpallot]

Theres no point going for e30 m3 stuff unless you want 5 stud, in which case you can simply fit the drive flanges to (available new from bmw) to a standard e30 disc braked arm- the trailing arms are the same

reason for going z3m is bigger bearings in the trailing arms and slightly stronger shafts together with the vented discs. not worth the expense though as the next week link is the diff output flange in the 188mm diff.

either keep it standard or go the whole hog