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

Diff. Identification

Thread Tools
 
Search this Thread
 
Old Feb 1, 2010 | 03:00 PM
  #1  
GoodfellaFD3S's Avatar
Thread Starter
Original Gangster/Rotary!
Veteran: Army
Tenured Member: 25 Years
Liked
Loved
iTrader: (213)
 
Joined: Mar 2001
Posts: 30,782
Likes: 641
From: FL-->NJ/NYC again!
Diff. Identification

Wondering if anyone could identify this diff. for me. Was told it was an S4 TII Limited slip. Please Help me before i actually install it. Thanks!





Reply
Old Feb 1, 2010 | 03:17 PM
  #2  
RotaryEvolution's Avatar
Sharp Claws
Tenured Member 15 Years
iTrader: (30)
 
Joined: Oct 2003
Posts: 5,107
Likes: 50
From: Central Florida
the hair tells me that it looks like a viscous, since there is nowhere to pull it apart to to change the clutches.

but honestly i'm not sure. that part is interesting though, as i recall i thought the clutch type had windows like most domestics for side gear installation.

nm, it's rear loaded. i'm seeing if i can find any other identifying markings on later model units.
Reply
Old Feb 1, 2010 | 04:03 PM
  #3  
RotaryEvolution's Avatar
Sharp Claws
Tenured Member 15 Years
iTrader: (30)
 
Joined: Oct 2003
Posts: 5,107
Likes: 50
From: Central Florida
since i can't remember exactly what the differences were from externally visual, it's been a while, i just am linking to a clutch type rebuild thread with detailed pictures. it may be for a GSL-SE but the general assembly should look almost identical to those pictured.

https://www.rx7club.com/1st-gen-archive-71/drivetrain-lsd-shot-need-rebuild-kit-581550/
Reply
Old Feb 3, 2010 | 03:07 PM
  #4  
GoodfellaFD3S's Avatar
Thread Starter
Original Gangster/Rotary!
Veteran: Army
Tenured Member: 25 Years
Liked
Loved
iTrader: (213)
 
Joined: Mar 2001
Posts: 30,782
Likes: 641
From: FL-->NJ/NYC again!
Can anyone confirm that this is an S4 T2 diff? My buddy plans to install this in his FD, it was sold to him as such and we just want to make sure.
Reply
Old Feb 3, 2010 | 03:07 PM
  #5  
G's 3rd Gen's Avatar
Eats, Sleeps, Dreams Rotary
Tenured Member: 20 Years
iTrader: (11)
 
Joined: Sep 2003
Posts: 3,066
Likes: 7
From: Home of the Rolex 24
bump 4 WTF is this? G
Reply
Old Feb 4, 2010 | 12:45 PM
  #6  
RotaryEvolution's Avatar
Sharp Claws
Tenured Member 15 Years
iTrader: (30)
 
Joined: Oct 2003
Posts: 5,107
Likes: 50
From: Central Florida
did you even look at the thread i linked and look for the clutch "sandwich"? it does look like a clutch type S4, an n/a won't fit in the case, it's too small.

in all honesty you shouldn't be tossing it in anyways without doing the suggestions in that thread. even at low mileage these clutch diff's have weak spring tension on the clutch packs due to age and will be fairly weak for traction. what you do need is to verify that it is a turbo diff case and not an n/a. i don't have exact ring and pinion measurements but i'm sure there should be something in the FSM to help you identify it such as ring dimensions.

this is especially important since i'm sure this is being upgraded from the weaker torsen type diff due to power restraints. the more you slip the clutches due to power and launching the faster it will wear to the point that it will need a full rebuild and these diffs aren't cheap to rebuild(no aftermarket clutch suppliers that i have heard of, OE parts are $550-700 for just the simple clutch pack). mine has made it over 200k miles and still somewhat grips but it sure isn't happy when i do get on the throttle, i do dread going into it so you may as well think of doing it before installing it.
Reply
Old Feb 7, 2010 | 05:01 PM
  #7  
GoodfellaFD3S's Avatar
Thread Starter
Original Gangster/Rotary!
Veteran: Army
Tenured Member: 25 Years
Liked
Loved
iTrader: (213)
 
Joined: Mar 2001
Posts: 30,782
Likes: 641
From: FL-->NJ/NYC again!
I did scan through the thread you linked and it does appear to be a clutch type diff, what I would like to know is whether or not it's from a T2. It's definitely a low mileage unit and does not need to be rebuilt.

I can't believe that no one in the entire FC universe has a picture of their s4 t2 diff? There used to be a great write up on a miata site full of pics but it's unfortunately down.
Reply
Old Feb 7, 2010 | 09:42 PM
  #8  
RotaryEvolution's Avatar
Sharp Claws
Tenured Member 15 Years
iTrader: (30)
 
Joined: Oct 2003
Posts: 5,107
Likes: 50
From: Central Florida
measurements are about the only thing you can use to identify it. i'm quite sure it looks nearly identical to a GXL clutch type, just larger. the ring gear diameter obviously giving it away.
Reply
Old Feb 8, 2010 | 10:07 AM
  #9  
lonewolfrx's Avatar
Rotary Enthusiast
Tenured Member: 20 Years
 
Joined: Mar 2003
Posts: 783
Likes: 2
From: Las Vegas
ill try and find one my spare t2 difs and open it up . if you still havent figured it out. I was gonna open it up anyways since it needs new bearings. If i find it today in my storage ill open it up and take photos for you
Reply
Old Feb 8, 2010 | 06:56 PM
  #10  
G's 3rd Gen's Avatar
Eats, Sleeps, Dreams Rotary
Tenured Member: 20 Years
iTrader: (11)
 
Joined: Sep 2003
Posts: 3,066
Likes: 7
From: Home of the Rolex 24
Originally Posted by lonewolfrx
ill try and find one my spare t2 difs and open it up . if you still havent figured it out. I was gonna open it up anyways since it needs new bearings. If i find it today in my storage ill open it up and take photos for you
Sweet !That would be great! G
Reply
Old Feb 8, 2010 | 08:03 PM
  #11  
NoPistons!'s Avatar
Tango Down
Tenured Member 05 Years
iTrader: (3)
 
Joined: Sep 2008
Posts: 2,895
Likes: 3
From: SC/NC


This is an s4 clutch type. Take note of the cammed ramps and clutch pack on the far right end.

TII and N/A diffs are nearly identical except the TII unit is LARGER.


I have no idea what that is there but i'm positive it's not an oem clutch type lsd from either fc platform.

Also, it should not take you $600-700 hp to achive good lock from one of these.

I have 6 springs and 6 clutch disks in mine. It locks up fine and i know the clutch discs are oe factory equipment never replaced.
Reply
Old Feb 11, 2010 | 11:59 AM
  #12  
lonewolfrx's Avatar
Rotary Enthusiast
Tenured Member: 20 Years
 
Joined: Mar 2003
Posts: 783
Likes: 2
From: Las Vegas
they both looks slightly alike but you can def tell the differences.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Josh83rx7
1st Generation Specific (1979-1985)
4
Sep 24, 2015 11:47 AM
gtcd
1st Generation Specific (1979-1985)
3
Sep 17, 2015 01:15 PM
Michael Mansour
New Member RX-7 Technical
7
Aug 18, 2015 03:13 AM
akageals
2nd Generation Specific (1986-1992)
7
Dec 8, 2008 03:41 PM




All times are GMT -5. The time now is 01:33 AM.