2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

How To: Swapping miata torsen LSD into N/A FC diff housing

Thread Tools
 
Search this Thread
 
Old 07-09-03, 06:04 PM
  #26  
Senior Member

 
mac_dad6's Avatar
 
Join Date: Oct 2002
Location: brigham city utah
Posts: 310
Likes: 0
Received 0 Likes on 0 Posts
what is the difference with the na and turbo diff. is it just cause the miata torsen cant handle the turbo motors extra power?
Old 07-09-03, 06:07 PM
  #27  
Do a barrel roll!

Thread Starter
iTrader: (4)
 
Rxmfn7's Avatar
 
Join Date: Oct 2001
Location: Lower Burrell, PA
Posts: 7,529
Likes: 0
Received 2 Likes on 2 Posts
No, they are different sizes. If I remember correctly the N/A uses a 7" ring and the Turbo uses an 8".
Old 07-09-03, 07:44 PM
  #28  
In Full Autist Cosplay

iTrader: (1)
 
Black13B's Avatar
 
Join Date: Nov 2002
Location: Alberta
Posts: 2,330
Likes: 0
Received 0 Likes on 0 Posts
Originally posted by Icemark
The gear ratio doesn't change, that is why you remove the old ring and put it on the new diff.

The miata ring and pinion are the wrong lengths and sizes to use in the FC diff. assembly.
ok this just confused me..

its just a ring gear swap, correct?
Old 07-09-03, 08:37 PM
  #29  
Former Moderator. RIP Icemark.
 
Icemark's Avatar
 
Join Date: Apr 2001
Location: Rohnert Park CA
Posts: 25,896
Likes: 0
Received 19 Likes on 19 Posts
Yes, and no

Its a diff swap keeping the existing FC ring and pinion.

If you changed the ring, (effectively changing the gearing) then you would have to re-space the pinion.
Old 07-09-03, 08:55 PM
  #30  
Do a barrel roll!

Thread Starter
iTrader: (4)
 
Rxmfn7's Avatar
 
Join Date: Oct 2001
Location: Lower Burrell, PA
Posts: 7,529
Likes: 0
Received 2 Likes on 2 Posts
Originally posted by Icemark
Yes, and no

Its a diff swap keeping the existing FC ring and pinion.

If you changed the ring, (effectively changing the gearing) then you would have to re-space the pinion.
Yes, this is true. And I think that setting the pinion depth for a new ring and pinion set is something that is beyond most people's abilities (mine anyway). There are many special tools needed, and you really need to understand what you are doing.
Old 07-09-03, 10:54 PM
  #31  
Newbie
 
Join Date: Jan 2003
Location: Tomball, TX
Posts: 0
Likes: 0
Received 0 Likes on 0 Posts
Originally posted by Rxmfn7
Yes, this is true. And I think that setting the pinion depth for a new ring and pinion set is something that is beyond most people's abilities (mine anyway). There are many special tools needed, and you really need to understand what you are doing.
well the only tools really needed are a dail indicator to check backlash and some anerobic paint to check pinion depth.
Old 07-09-03, 10:56 PM
  #32  
Former Moderator. RIP Icemark.
 
Icemark's Avatar
 
Join Date: Apr 2001
Location: Rohnert Park CA
Posts: 25,896
Likes: 0
Received 19 Likes on 19 Posts
here is the FD/FC turbo Torsen diff:
Old 07-15-03, 09:52 PM
  #33  
Senior Member

 
my_jdm_rx7's Avatar
 
Join Date: Feb 2002
Location: Michigan
Posts: 271
Likes: 0
Received 0 Likes on 0 Posts
What year of Miata did you use?
Old 08-25-03, 06:54 PM
  #34  
Do a barrel roll!

Thread Starter
iTrader: (4)
 
Rxmfn7's Avatar
 
Join Date: Oct 2001
Location: Lower Burrell, PA
Posts: 7,529
Likes: 0
Received 2 Likes on 2 Posts
94+ 1.8 Miatas use the torsen LSD. But not all of them, you just need to get lucky I guess Seriously though, I have no idea on how to tell if the miata will have the LSD or not. One method Ive heard is that if it is a 5-speed and has cruise control, it will have LSD. Im not sure how true it is, but every one Ive seen with cruise has had LSD.

Last edited by Rxmfn7; 08-25-03 at 06:57 PM.
Old 10-02-03, 11:43 AM
  #35  
Do a barrel roll!

Thread Starter
iTrader: (4)
 
Rxmfn7's Avatar
 
Join Date: Oct 2001
Location: Lower Burrell, PA
Posts: 7,529
Likes: 0
Received 2 Likes on 2 Posts
Just a small update for anyone interested. I was having problems with my diff at 1st. One thing, is that on S5 LSDs, the rear end uses un-equal length axle stubs. When using these on a torsen, or clutch unit, the longer stub will cross over and cause the LSD unit to be "fused" together, making it impossable for both wheels to spin at anything other than the same speed. I got a set of S4 axles stubs and it corrected that problem. Another thing, the backlash will need adjusted properly to spec. My gears were whirring when I put the rear end back in, so I needed to drop it again and adjust the backlash. It is a faily simple procedure, although you will need a few special tools (dial indicator and something to turn the things on the side of the bearings. Mazda calls for a differential wrench, but anything you can turn them with will be fine) The procedure to set backlash is explained in chapter 9 of the FSM, pages 9.43-9.45. Hope this helps..
Old 10-02-03, 06:04 PM
  #36  
procrastination engineer

iTrader: (1)
 
Mills's Avatar
 
Join Date: Mar 2003
Location: up to my ass in alligators
Posts: 1,270
Received 1 Like on 1 Post
I thought this was an n/a housing-you were using tII axle shafts? Will the shafts from an n/a housing work? Or do you need the tII shafts?
Old 10-02-03, 06:58 PM
  #37  
Do a barrel roll!

Thread Starter
iTrader: (4)
 
Rxmfn7's Avatar
 
Join Date: Oct 2001
Location: Lower Burrell, PA
Posts: 7,529
Likes: 0
Received 2 Likes on 2 Posts
Originally posted by Mills
I thought this was an n/a housing-you were using tII axle shafts? Will the shafts from an n/a housing work? Or do you need the tII shafts?
I never said anything about a Turbo2 housing. I was using a S5 N/A housing, but with the viscous LSD the axle shafts are unequal lengths... T2 and N/A rear end pieces are not compatable.
Old 10-02-03, 07:35 PM
  #38  
Displacement > Boost

 
88IntegraLS's Avatar
 
Join Date: Oct 2002
Location: Mississippi
Posts: 3,503
Likes: 0
Received 0 Likes on 0 Posts
Archive material. Great job!


PS you let that viscous LSD go for only $99?
Old 10-03-03, 10:39 AM
  #39  
Str8 Waggin

 
Rexmanwolf's Avatar
 
Join Date: Apr 2003
Location: Miami,Fl
Posts: 751
Likes: 0
Received 0 Likes on 0 Posts
OK, Guys i read this whole thing and just ended up getting lost in the process!! OK, can i do this on My 91 Vert. Its n/a. Also will that make my non LSD into an LSD?? And in simple tems for us non mechanical guys explain it to me.
Example: "u take the roung thing and put it in the other round thing" thanks hehe
Old 10-03-03, 10:46 AM
  #40  
procrastination engineer

iTrader: (1)
 
Mills's Avatar
 
Join Date: Mar 2003
Location: up to my ass in alligators
Posts: 1,270
Received 1 Like on 1 Post
Yeah, I meant doing it on a non-lsd n/a housing...
Old 10-04-03, 08:57 PM
  #41  
Just Call Me Terminator!

iTrader: (4)
 
vosko's Avatar
 
Join Date: Feb 2001
Location: NJ
Posts: 7,848
Likes: 0
Received 0 Likes on 0 Posts
umm clutch lsd's are much stronger than torsens!!!!
Old 10-04-03, 09:00 PM
  #42  
Do a barrel roll!

Thread Starter
iTrader: (4)
 
Rxmfn7's Avatar
 
Join Date: Oct 2001
Location: Lower Burrell, PA
Posts: 7,529
Likes: 0
Received 2 Likes on 2 Posts
Originally posted by vosko
umm clutch lsd's are much stronger than torsens!!!!
This is true, but considering the GTUs unit originally had a viscous, and the rear end is going in a car that will never see over 250rwhp, its not much of a problem. If I was building a higher HP car, clutch type would be a much better option...
Old 10-04-03, 09:13 PM
  #43  
Just Call Me Terminator!

iTrader: (4)
 
vosko's Avatar
 
Join Date: Feb 2001
Location: NJ
Posts: 7,848
Likes: 0
Received 0 Likes on 0 Posts
i could break a torsen in a T2.... never broke a VLSD though
Old 10-04-03, 09:24 PM
  #44  
Former Moderator. RIP Icemark.
 
Icemark's Avatar
 
Join Date: Apr 2001
Location: Rohnert Park CA
Posts: 25,896
Likes: 0
Received 19 Likes on 19 Posts
Originally posted by vosko
i could break a torsen in a T2.... never broke a VLSD though
You can't break a VLSD unless you open it up or are in a accident that distroys the rear end.
Old 10-04-03, 09:27 PM
  #45  
Do a barrel roll!

Thread Starter
iTrader: (4)
 
Rxmfn7's Avatar
 
Join Date: Oct 2001
Location: Lower Burrell, PA
Posts: 7,529
Likes: 0
Received 2 Likes on 2 Posts
Originally posted by vosko
i could break a torsen in a T2.... never broke a VLSD though
Yes, but you can't really break a VLSD, being that there are really no parts in it. It just uses the resistance of the fluid to bring the wheels to the same speed. You cant break fluid
Old 10-04-03, 09:59 PM
  #46  
Just Call Me Terminator!

iTrader: (4)
 
vosko's Avatar
 
Join Date: Feb 2001
Location: NJ
Posts: 7,848
Likes: 0
Received 0 Likes on 0 Posts
i bet i could twist the diff if i tried
Old 10-22-04, 12:13 AM
  #47  
Finally I have LSD

 
twistedriver's Avatar
 
Join Date: Jul 2003
Location: Los Angeles
Posts: 528
Likes: 0
Received 0 Likes on 0 Posts
Rxmfn7. Did you adjust the backlash with the diff case out or did you adjust the backlash by removing the rear half of the case? I need to adjust me rear end and i really hate taking the whole thing out. Thanks!
Old 10-22-04, 09:42 AM
  #48  
Jesus is the Messiah

 
Tofuball's Avatar
 
Join Date: May 2003
Location: Silver Spring, MD
Posts: 4,848
Received 0 Likes on 0 Posts
I'm posting here just so I can search and find this awesome thread easier.
Old 10-22-04, 12:36 PM
  #49  
7s bein a pain in the ass

 
aka_rocket's Avatar
 
Join Date: Nov 2003
Location: Chico, CA
Posts: 704
Likes: 0
Received 0 Likes on 0 Posts
sounds great. i should start finding a miata's torsen when mine goes out.
Old 10-22-04, 12:46 PM
  #50  
Senior Member

iTrader: (3)
 
JDuncan's Avatar
 
Join Date: Mar 2001
Location: Louisville, KY, USA
Posts: 702
Likes: 0
Received 1 Like on 1 Post
I just went through the FD torsen install into my TII diff.



Quick Reply: How To: Swapping miata torsen LSD into N/A FC diff housing



All times are GMT -5. The time now is 01:07 PM.