Fitting a Z3 diff

Need technical Q/A then you're in the right place

Moderator: martauto

Post Reply
User avatar
Y_Cymro
E30 Zone Newbie
E30 Zone Newbie
Posts: 98
Joined: Sat Oct 08, 2005 11:00 pm
Location: South Wales

Tue Dec 29, 2009 10:13 pm

To go with my M50 conversion I have a Z3 lsd to replace the standard diff in my 316i Touring. Is the new diff a straight swap?
Image
User avatar
Kos
E30 Zone Team Member
E30 Zone Team Member
Posts: 15546
Joined: Tue Jul 12, 2005 11:00 pm
Location: London / Cyprus
Contact:

Tue Dec 29, 2009 10:15 pm

pretty much yes

if its of a ZM , you'll need to swop the put put flanges for some e30 ones to mate up with your drive shafts
PUKAR DESIGNS - Reproduction BMW Decals Labels Sticker & Number Plates
www.pukardesigns.com
www.facebook.com/pukar.designs/
IG Pukar.Designs
User avatar
Y_Cymro
E30 Zone Newbie
E30 Zone Newbie
Posts: 98
Joined: Sat Oct 08, 2005 11:00 pm
Location: South Wales

Wed Dec 30, 2009 12:20 pm

Kos wrote:pretty much yes

if its of a ZM , you'll need to swop the put put flanges for some e30 ones to mate up with your drive shafts
Sorry, I should have said it's from a Z3 2.8 with torsen diff.
So it should bolt straight on without changing flanges?
Image
Jonsku
E30 Zone Regular
E30 Zone Regular
Posts: 848
Joined: Sun Jul 24, 2005 11:00 pm
Location: Global

Wed Dec 30, 2009 12:46 pm

Yes it should be direct bolt-on, if flanges are different (prop- / driveshaft) you can swap them from your e30 diff.
E30 Cabrio M-Tech, powered by V8
E34 M5 3.8 x 2
Alpina D10 Touring #33/93

E46 318i Touring
Toyota Hiace 4wd
User avatar
N00b
E30 Zone Addict
E30 Zone Addict
Posts: 3954
Joined: Wed Oct 22, 2008 11:00 pm
Location: Purgatory

Wed Dec 30, 2009 12:50 pm

Is the Z3 diff a straight swap, or do you put the Z3 internals into an e30 case?
bss325i
E30 Zone Team Member
E30 Zone Team Member
Posts: 24536
Joined: Sat Jan 20, 2007 11:00 pm
Location: London/Surrey

Wed Dec 30, 2009 1:08 pm

N00b wrote:Is the Z3 diff a straight swap, or do you put the Z3 internals into an e30 case?
Straight swap. Z3 uses an 30 type rear beam.
http://www.bmrperformance.co.uk

BMW and MINI specialist - Gatwick
User avatar
N00b
E30 Zone Addict
E30 Zone Addict
Posts: 3954
Joined: Wed Oct 22, 2008 11:00 pm
Location: Purgatory

Wed Dec 30, 2009 1:20 pm

bss325i wrote:
N00b wrote:Is the Z3 diff a straight swap, or do you put the Z3 internals into an e30 case?
Straight swap. Z3 uses an 30 type rear beam.
Good to know.
Does this mean the CWP are interchangeable between Z3 and e30, as if it does then it looks like a Z3 diff would be a good choice as it should be in better condition than an e30 item.
User avatar
Y_Cymro
E30 Zone Newbie
E30 Zone Newbie
Posts: 98
Joined: Sat Oct 08, 2005 11:00 pm
Location: South Wales

Wed Dec 30, 2009 1:33 pm

N00b wrote:
bss325i wrote:
N00b wrote:Is the Z3 diff a straight swap, or do you put the Z3 internals into an e30 case?
Straight swap. Z3 uses an 30 type rear beam.
Good to know.
Does this mean the CWP are interchangeable between Z3 and e30, as if it does then it looks like a Z3 diff would be a good choice as it should be in better condition than an e30 item.
I believe that the Z3 uses a medium case - hence my question whether the complete diff is a straight swap. A problem you might have is that the Z3 has a direct top gear so the diff ratios tend to be too high if you are using an E30 overdrive top gearbox.
Image
User avatar
Y_Cymro
E30 Zone Newbie
E30 Zone Newbie
Posts: 98
Joined: Sat Oct 08, 2005 11:00 pm
Location: South Wales

Wed Dec 30, 2009 1:35 pm

Thank you all for your help.
Image
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49358
Joined: Mon Jan 10, 2005 11:00 pm

Wed Dec 30, 2009 1:37 pm

Z3 diff fits straight on, but with the E30 gearbox and 1.6 M40 engine you'll need a calendar for 0 - 60 times!
User avatar
N00b
E30 Zone Addict
E30 Zone Addict
Posts: 3954
Joined: Wed Oct 22, 2008 11:00 pm
Location: Purgatory

Wed Dec 30, 2009 1:46 pm

Surely you could change the CWP for a more suitable e30 part to give a more desireable ratio?
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49358
Joined: Mon Jan 10, 2005 11:00 pm

Wed Dec 30, 2009 6:51 pm

N00b wrote:Surely you could change the CWP for a more suitable e30 part to give a more desireable ratio?
Then you have to set up the shims and crush tube. Generally reckoned to be a specialist (=expensive) job
User avatar
N00b
E30 Zone Addict
E30 Zone Addict
Posts: 3954
Joined: Wed Oct 22, 2008 11:00 pm
Location: Purgatory

Wed Dec 30, 2009 9:57 pm

Brianmoooore wrote:
N00b wrote:Surely you could change the CWP for a more suitable e30 part to give a more desireable ratio?
Then you have to set up the shims and crush tube. Generally reckoned to be a specialist (=expensive) job
Ah, my bad. I was under the impression that the actual workings of the LSD remained intact and all that was needed was to remove and change the final drive cog. Out of curiosity, what kind of money are we talking to have this done? Ballpark figure will be enough.
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49358
Joined: Mon Jan 10, 2005 11:00 pm

Wed Dec 30, 2009 10:16 pm

You'd be better off selling the Z3M diff to someone who's doing a m5x conversion, for which it's ideal, and sourcing a diff with a more suitable ratio, or better still, binning the 1.6 M40 yourself!
User avatar
WeBuyAnyCar
**BANNED**
Posts: 192
Joined: Wed Dec 16, 2009 11:00 pm

Wed Dec 30, 2009 10:30 pm

On this topic I hear e36 compacts have the same rear setup as an E30 so you can use the rear arms in 5 stud conversion and the diff on the e30.
Do the 318ti use a 4.11LSD?
User avatar
N00b
E30 Zone Addict
E30 Zone Addict
Posts: 3954
Joined: Wed Oct 22, 2008 11:00 pm
Location: Purgatory

Thu Dec 31, 2009 12:23 am

WeBuyAnyCar wrote:On this topic I hear e36 compacts have the same rear setup as an E30 so you can use the rear arms in 5 stud conversion and the diff on the e30.
Do the 318ti use a 4.11LSD?
Yeah I've heard that the compact uses the same rear suspension setup as the e30. Is the front end also e30?
User avatar
Kos
E30 Zone Team Member
E30 Zone Team Member
Posts: 15546
Joined: Tue Jul 12, 2005 11:00 pm
Location: London / Cyprus
Contact:

Thu Dec 31, 2009 2:11 am

no
PUKAR DESIGNS - Reproduction BMW Decals Labels Sticker & Number Plates
www.pukardesigns.com
www.facebook.com/pukar.designs/
IG Pukar.Designs
User avatar
WeBuyAnyCar
**BANNED**
Posts: 192
Joined: Wed Dec 16, 2009 11:00 pm

Thu Dec 31, 2009 4:19 am

So kos the rear end is the same yer.
But do they make a 4.11 LSD for them
User avatar
Kos
E30 Zone Team Member
E30 Zone Team Member
Posts: 15546
Joined: Tue Jul 12, 2005 11:00 pm
Location: London / Cyprus
Contact:

Thu Dec 31, 2009 4:36 am

same is 99% e30

LSD's are available but it depends what size diff case you want

use the search function, you'll find out all that you need to
PUKAR DESIGNS - Reproduction BMW Decals Labels Sticker & Number Plates
www.pukardesigns.com
www.facebook.com/pukar.designs/
IG Pukar.Designs
Rusty_McRusty
E30 Zone Newbie
E30 Zone Newbie
Posts: 143
Joined: Mon May 23, 2005 11:00 pm

Thu Dec 31, 2009 11:27 am

The 4.1 LSD on mine was sourced from the US by the previous owner, I believe it's a small case off an E30. Original owner of the diff was on here, tom_stickland. The diff works well with the M44, gives useable performance in the lower gears and is (obviously) livlier than the 3.9 that came with the car. Certainly wouldn't want to go any lower than 3.9 on mine, on a 1.6 the problem will be magnified somewhat!
bss325i
E30 Zone Team Member
E30 Zone Team Member
Posts: 24536
Joined: Sat Jan 20, 2007 11:00 pm
Location: London/Surrey

Thu Dec 31, 2009 12:39 pm

WeBuyAnyCar wrote:On this topic I hear e36 compacts have the same rear setup as an E30 so you can use the rear arms in 5 stud conversion and the diff on the e30.
Do the 318ti use a 4.11LSD?
At a guess i would say an LSD was an option (but im still doubtfull) on 318ti compacts but i have never seen or heard of on fitted.

They normally come with ASC.
http://www.bmrperformance.co.uk

BMW and MINI specialist - Gatwick
penton08
E30 Zone Camper
E30 Zone Camper
Posts: 1206
Joined: Sat May 10, 2008 11:00 pm

Thu Dec 31, 2009 1:50 pm

as above... and normally 318ti's will have a 3.38.1 diff.
User avatar
WeBuyAnyCar
**BANNED**
Posts: 192
Joined: Wed Dec 16, 2009 11:00 pm

Thu Dec 31, 2009 4:12 pm

bss325i wrote:
WeBuyAnyCar wrote:On this topic I hear e36 compacts have the same rear setup as an E30 so you can use the rear arms in 5 stud conversion and the diff on the e30.
Do the 318ti use a 4.11LSD?
At a guess i would say an LSD was an option (but im still doubtfull) on 318ti compacts but i have never seen or heard of on fitted.

They normally come with ASC.
Whats ASC
User avatar
Kos
E30 Zone Team Member
E30 Zone Team Member
Posts: 15546
Joined: Tue Jul 12, 2005 11:00 pm
Location: London / Cyprus
Contact:

Thu Dec 31, 2009 5:57 pm

penton08 wrote:as above... and normally 318ti's will have a 3.38.1 diff.
it depends if they are M42 or M44 powered


ASC = traction control
PUKAR DESIGNS - Reproduction BMW Decals Labels Sticker & Number Plates
www.pukardesigns.com
www.facebook.com/pukar.designs/
IG Pukar.Designs
Post Reply