It is currently Mon Oct 22, 2018 10:18 pm



Post new topic Reply to topic  [ 5 posts ] 
Author Message
 Post subject: Rebuilding BMW/ZF 188mm Limited Slip (25% -> 40% lock)
PostPosted: Wed Jan 09, 2013 9:49 am 
Offline
User avatar

Joined: Fri Dec 04, 2009 1:45 am
Posts: 588
Location: Pennsylvania, USA
ECU Model: S80 Pro
Distributor: DTA UK
Firmware Version: 73
This is real simple. For my turbo car I rebuilt one going from 25% to 60% lock by machining and fitting 4 clutches/dog plates in place of 2. For my daily driver '95 525i I decided to fit an LSD diff and rebuilt it for 3 clutches/dog plates which will result in a more calm 40% lock up. 60% is nice in the turbo car but tight radius turns result in tire chatter since the axles are so locked.

Image
'93 3.23 LSD Differential by Jon Kensy, on Flickr

Old clutches were in good shape:

Image
IMG_0055.jpg by Jon Kensy, on Flickr

Replacement clutch set:

Image
BimmerDiffs.com 3-Disc Upgrade by Jon Kensy, on Flickr

You just remove the end plates and then remove the ring gear/LSD carrier. You make sure that your carrier depth is ~96.8mm and your LSD cover plate is about 14.0x mm inset. Then, just swap out a spacer plate and old clutch/dog plates with new. ZF used a spacer in the diff that can be removed and is the exact same thickness as an additional clutch/dog plate. So, going from 2 clutch to 3 clutch is easy. 2 clutch to 4 clutch required machining down the carrier cover by the stack thickness difference, still not hard, though.

Old parts out:

Image
3.23:1 LSD 40% Lock-up Setup by Jon Kensy, on Flickr

Measuring backlash:

Image
3.23:1 LSD 40% Lock-up Setup by Jon Kensy, on Flickr

Spec is 0.06 - 0.014mm (0.0023 - 0.0055"). Mine measures in at 0.0041", well within spec.

Measuring backlash:


_________________
1992 700RWHP Pump Gas BMW


Top
 Profile  
 
 Post subject: Re: Rebuilding BMW/ZF 188mm Limited Slip (25% -> 40% lock)
PostPosted: Wed Jan 09, 2013 5:36 pm 
Offline

Joined: Sat Nov 12, 2011 6:24 pm
Posts: 96
Location: Montreal, Canada
ECU Model: S100 Pro
Firmware Version: 61
Nice Jon,
I did the same (3 clutch mod) with my 4.10 e30 diff in my ti. Did you use thicker Porsche plates or the stock thickness BMW plates? I went with 2.1mm Porsche Motorsport dog ear plates rather than the standard 2.0mm BMW ones for a bit more lock-up.


Attachments:
IMG_1663.JPG
IMG_1663.JPG [ 589.49 KiB | Viewed 9707 times ]
IMG_1643.JPG
IMG_1643.JPG [ 644.63 KiB | Viewed 9707 times ]
IMG_1633.JPG
IMG_1633.JPG [ 588.73 KiB | Viewed 9707 times ]
Top
 Profile  
 
 Post subject: Re: Rebuilding BMW/ZF 188mm Limited Slip (25% -> 40% lock)
PostPosted: Wed Jan 09, 2013 10:57 pm 
Offline
User avatar

Joined: Fri Dec 04, 2009 1:45 am
Posts: 588
Location: Pennsylvania, USA
ECU Model: S80 Pro
Distributor: DTA UK
Firmware Version: 73
Simon I used a kit from www.bimmerdiffs.com they measure a hair over 2.0mm

_________________
1992 700RWHP Pump Gas BMW


Top
 Profile  
 
 Post subject: Re: Rebuilding BMW/ZF 188mm Limited Slip (25% -> 40% lock)
PostPosted: Mon Sep 19, 2016 5:06 pm 
Offline

Joined: Sat Sep 03, 2016 9:42 pm
Posts: 6
ECU Model: No ECU
Firmware Version: 30.00
I need to rebuild my e46 m3 diff it's knocking like crazy the oil leaked out, I wonder if they have any rebuild kits for mine.


Top
 Profile  
 
 Post subject: Re: Rebuilding BMW/ZF 188mm Limited Slip (25% -> 40% lock)
PostPosted: Mon Sep 19, 2016 10:08 pm 
Offline

Joined: Sat Nov 12, 2011 6:24 pm
Posts: 96
Location: Montreal, Canada
ECU Model: S100 Pro
Firmware Version: 61
The E46 M3 uses the larger 210mm unit and they are rebuildable. Contact Dan at Diffsonline (http://diffsonline.com/) and he should be able to help you out.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Theme designed by stylerbb.net © 2008
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
All times are UTC - 5 hours