Open diff to LSD

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

Moderator: martauto

Quaser
E30 Zone Addict
E30 Zone Addict
Posts: 2622
Joined: Sun Jan 09, 2005 11:00 pm
Location: West London

Post Tue Sep 13, 2005 6:36 pm

Hi Guys

Is it possible to convert an open diff to an LSD?

I know this was discussed breifly a few months ago, but there was no conclusion to this so i am posting again!!!


Q
Demlotcrew
E30 Zone Team Member
E30 Zone Team Member
Posts: 13329
Joined: Mon Dec 20, 2004 11:00 pm
Location: East Anglia

Post Tue Sep 13, 2005 8:27 pm

IF you have the clutch pack then yes!

A
Quaser
E30 Zone Addict
E30 Zone Addict
Posts: 2622
Joined: Sun Jan 09, 2005 11:00 pm
Location: West London

Post Tue Sep 13, 2005 11:41 pm

where can i get a clutch pack from please?

Q
Chaos
E30 Zone Addict
E30 Zone Addict
Posts: 2460
Joined: Tue Jan 11, 2005 11:00 pm
Location: Cardiff, South Wales

Post Wed Sep 14, 2005 12:58 am

surely cheaper and easier to just buy an lsd diff
Chaos
causing havoc and mayhem wherever i go

Image
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49360
Joined: Mon Jan 10, 2005 11:00 pm

Post Wed Sep 14, 2005 9:34 am

Demlotcrew wrote:IF you have the clutch pack then yes!

A
If it's that easy, why are people always so concerned as to what the ratio is when they buy an LSD?
M3Compact
E30 Zone Regular
E30 Zone Regular
Posts: 506
Joined: Mon Jan 10, 2005 11:00 pm

Post Wed Sep 14, 2005 10:11 am

Brianmoooore wrote:
Demlotcrew wrote:IF you have the clutch pack then yes!

A
If it's that easy, why are people always so concerned as to what the ratio is when they buy an LSD?
You need the whole cluster, (housing, end plate, clutches etc)

It's not as difficult as some think, to transfer the LSD unit in to an open diff'.
Omi
Witty custom rank.
Posts: 1478
Joined: Sun Jan 09, 2005 11:00 pm
Location: Darlington, North East

Post Thu Sep 15, 2005 5:19 pm

Ok...

I've got a 3.91 LSD Large case...

And a 4.10 Open small case...

Will I be able to make a 4.10 LSD? Is the Pinion height the same on a small and large case diff, and will it just be a case of moving the crown and pinion from the small case into the big case with a few new bearings and seals?

Cheers guys.
...or is it?
User avatar
karlp
E30 Zone Regular
E30 Zone Regular
Posts: 280
Joined: Wed Jan 12, 2005 11:00 pm
Location: Southampton

Post Thu Sep 15, 2005 5:24 pm

The internals on a small case are actually weaker (so I was told by a BMW technician).
Karl
Demlotcrew
E30 Zone Team Member
E30 Zone Team Member
Posts: 13329
Joined: Mon Dec 20, 2004 11:00 pm
Location: East Anglia

Post Thu Sep 15, 2005 10:35 pm

Yes they are weaker.

No you cant make a LSD from your Large into your small case.

Like i said, you need the clutch pack. Brian not everyone can rebuild a diff, but if i had the correct tools it would be very easy.

A
jaistanley
E30 Zone Addict
E30 Zone Addict
Posts: 2517
Joined: Tue Jan 18, 2005 11:00 pm
Location: Coventry and Essex

Post Fri Sep 16, 2005 9:48 am

It should be possible to adjust the pre-tension on the clutchpack to provide more lockup too. Think it's done by re-shimming the pack. Have a friend who does it on his rally cars I believe.

Make it a bit more aggressive to drive though :eek:

Jai