Ok i have a 87 RX7 and it's a 4 lug. I assum that i don't have an LSD. I was just wondering if i could get an LSD from like a TII or GTUs or GXL and just put it on my car. Or do i have to change anything else like the driveshaft or like the axles??

 

I believe any GTU/GXL model LSDs will fit...the turbo's and GTUs will not, as they are different...not positive on that, but i am pretty sure any n/a LSD from an 86-88 will fit your car..

 

The turbo 2 limited slip will not work. The turbos use an 8" LSD and ring gear while the N/A uses a 7". You can use any N/A FC LSD, but if you get a viscous unit (89-91) you will need the axle stubs from a S5 LSD also, as they are different lengths. You can also use a torsen LSD from a 94+ miata, as I have done myself (although still having a little trouble with it...mostly my fault )though)

 

those 94+ miata's need to be 1.8L to have the same 7" differential.

Also, the GTUs has a 7", not an 8". The phrase "a turbo II, minus the turbo"... bullshit.

 

The GTUs uses the sme size differential (7") as any other N/A, and is not the same size as the Turbo differentials (8").

All N/A and Miata (NA, NB) differentials are 7inch gear sets and interchangeable.

All FD, FE, 929 (HD, HE), and FC Turbo II differentials are 8 inch gear sets and interchangeable.

However you can not use a 8 inch gear set differential in a 7" gear set rear end.

 

Yes, but all 94+ miatas are 1.8, its the 89-93 that are the 1.6. Not all miatas come with the LSD though, there is a list posted somewhere on www.miataforum.com of which models have various options that can help you out if looking for a LSD. And yes, the GTUs has the same 7" LSD that any other N/A has. My torsen unit is in a GTUs 4.3 diff..

 

Im an idiot....

 

Hate to contradict Mark; but you are mistaken.

The 1.6L Miata's used a 6" rear, that is not interchangable.

Here's a very handy page that every N/A forum member should have bookmarked...

The Miata Drivetrain Interchange Guide

 

So does this mean that I can just drop in the gears from the B2200 pick-up into my 86 gearbox??? And get a lower track gearing?
There are tonnes of them at our local junkyard

'85+ B2000/2200
3.622:1
2.186:1
1.419:1
1:1
.858:1

86-91 NA RX-7
3.475:1
2.002:1
1.366:1
1:1
.691, 86=.711

 

Ok, before i make any assumptions. Let me get something straight, i can take an LSD from a GTU, GTUs, and GXL, and just bolt it rite on to my RX7?? am i correct.

To make sure i have a 87 RX7 4 lug ok.

 

Any non-turbo FC LSD is interchangeable into any other non-turbo FC diff. The turbos cannot be interchanged with non-turbos.

 

Yep, you are right... not all NA (first gen Miatas) had the 7 inch. Only the 94 and later.

 

So if i get an LSD from any N/A FC. i don't have to do any other thing, but just bolt it on right??

 

im am doing a swap over from my 87 TII into my 86 base. when i swap everything over, i will also be swapping the whole rear end; tranny, driveshaft, axles, rear diff, everything. will these TII parts fit in the 86?
Josh

 

Yes, they will all fit. Be advised that you will also need the turbo starter and flywheel if using a turbo tranny though. (Not sure if you meant that you were just swapping driveline parts, or engine as well...)

 

So if i get any LSD from any N/A FC it will fit on my 87 FC that has no LSD. I don't need to get drive axle or anything else just the LSD, and it will bolt rite on??

THIS IS A FACT RITE??

 

I talked to Mazdatrix and they said that you could swap out the LSD unit from the housing and put it into your current one while keeping the 4 lug setup. I've also read that you CAN'T have LSD and keep your 4 lug setup.

So can you get the LSD unit (from a s4 GXL) and put it into a four lug (s4 non-lsd) "pumpkin" while keeping the four lug setup?