tried the tech section, but I'm in a bind and need some quick answers. Hopefully you guys can help...

I recently purchased a differential which was supposedly a 2way Re-Amimeya for a turbo model. Received it in the mail today.
Disassembled it to double check the condition of the plates and internals, and this is what I find:




Looks an awful lot like a stock 1way S4 Turbo Clutch-type to me. Pinion spider ramps seem to be a dead give away. The weird thing is that the s4 turbo stubs don't seem to fit quite right, off by maybe 1/4" from one side to the next.
I've never taken an FC clutch-type apart, or seen the guts of it. I assume this is just a stock s4 Tii diff, but I figured I'd check with you guys anyway.
The part I am holding in the third picture seems like it could be adjusted for certain stub shaft lengths.
I'd like to make an accurate identification of this diff before I return it.

I know plenty of you have the s4 clutch-type...
Does all this look familiar to you?

 

Upon further inspection, It seems that the piece in the third pic is some sort of thrust part that allows you to adjust the pre-load of the clutch plates. Three different positions/settings that can be changed while the unit is sealed, using the 3/4" hex head to raise or lower the position.

Were the stock units adjustable?

 

i had one ten? years ago, looks a bit different

http://www.vosko.net/photos/fd/rediffapart/

 

I would say that a stock unit would not be adjustable as I've never heard of that for s4 clutch types. thats why people shim the diffs with thicker plates, beer cans,etc. so they can get them to lock harder/faster. I don't have any first hand knowledge though so my .02

 

yeah. From those pics, yours was definitely a 2way, But not adjustable?

 

Thats what I figure... maybe an aftermarket 1way adjustable. And it looks as though someone already tried to shim the inside thrust piece with more washers (not the usual clutch plate shim).
But I'm still puzzled on the idea of why the stubs do not fit.

 

arent S5/S4 turbo stub shafts different sizes/diameters? maybe that could have something to do with it

i have no idea.

 

Yes. s5 turbo stubs are different for driver/passenger side, S4 turbo stubs are both equal length.
I have a pair of each. S4 stubs almost work, but no cigar. Fackin' mystery diff.
Anybody have some shots of a disassembled stocker?

 

I just looked at my mazdaspeed. It does not have that bolt head in the middle.

 

Strange...
Mazdaspeed and Re-A's are supposedly made in the same factory, so guess its safe to say this isnt either of those. Thank you for checking.

I have a question for you though:
I assume you're using the s4 stubs. Do your stub shafts lock in place, or slide back and forth freely? Because when I take the adjustment pieces out of mine, the stubs will sink into the diff way too far.

 

any chance it may be for an FD?

 

Its very possible. But they're interchangeable with s4 diffs, so it would still work. I had a welded FD torsen in the car before I bought this.
I dunno, man. My best guess is that its a stock s4 lsd, with an adjustable spider gear cam from mazdaspeed or another car or something. Some MacGyver ****.

 

Have you tried matching it to your ring gear to see if it will even bolt up? and i dont know exactly what you were trying to ask about the stub shafts sliding all the way in. But yes i am using s4 stub shafts.

PM me your number or email and i will send you shots of my diff so you can visually compare.