S13 240SX has R200?

[EricB]

What rear end do S13 240SX's have?

Is it an R200? It looks more compact and the bolt arrangement for the mustache bar seems to be setup differently...

won't work on our cars? curious...

-e

[Pennyman]

I've heard that the bolt holes that hold the ring gear to the differential unit are a different size, but it shouldn't matter as long as the bolts are torqued down correctly. I've been researching this as well, partly because coming across a R200 LSD is so rare. 240sx's have viscous LSD's and therefore aren't as "high performance" as the clutch style units. But if one 240sx diff fits a Z diff case, then most should.

[Black Beaut]

The S13 and S14 200SX diffs are the short nose R200 variety. They can be made to fit but requires a degree of fabrication. Pretty much the same as trying to fit an R230 from a 300ZXTT. Also if you get one with a viscous LSD then you have to use the out put shafts from that as they are different to open R200 shafts - which is pretty annoying

The S12 Silvia 200SX, call it what you will, has a long nose R200 which with the correct moustache bar and drive shafts is a straight bolt in job. Know idea what ratios you got out there in the S12 or if any came with LSD.

Or as Pennyman suggests you can just swap the internal LSD unit from an 200SX in to a long nose R200 case, just make sure that if your ring gear uses 10mm bolts and the diff unit uses 12mm bolts to have some spacer/bushes made up to fill out the extra 2mm difference.

Cheers,

Rob

[Hypertek]

I got a Nismo 2 way LSD pumpkin for open diff s13... which im now considering a S30, this should be swap into a r200 housing right?

[EricB]

Hey Rob "Black Beaut",

If you can fit a newer 240SX intended LSD out of a short-nose R200 into an older 280Z/280ZX R200 aren't you going to run into a problem when selecting the right ring and pinion?

Ie: the pinion that matches the 12mm ring gear (which bolt to the newer LSD) will in effect be too short for the longer older R200, and at the same time using an older R200 ring and pinion won't bolt up to the LSD because they use 10mm bolts...

Is that right? So basically it won't work?

-e

[Black Beaut]

Hi Eric,

Yeah you can't change the ring and pinion gears from the short nose to the long nose, what you need to do is remove the actual diff centre, so you remove the ring gear from that and then swap that in to the long nose case using the ring and pinion set up from the long nose diff. That's where the 10mm and 12mm bolts come in. Early R200 ring gears where held to the diff centre with 10mm bolts, later R200 use 12mm.

Cheers,

Rob

[EricB]

So just so we've got this spelled out for everyone who wants to go this route:

If you're going to use an LSD intended for a 240SX you ought to get an aftermarket one intended for a 240SX that came without LSD originally. If you get an LSD for a 240SX that came WITH LSD (it was a viscous unit) then you have to do additional legwork to get VLSD stub axles as regular ones won't work.

Because your modern 240SX LSD uses 12mm gears to secure the ring gear you ought to be looking at getting an R200 rear end from an 84-9 300ZX because the 75-83 R200 have their ring gear attached by 10mm bolts like the R180.

And if on top of that I want a 3.9 ratio I should be looking at an 87-9 NA 300ZX. I will need the stub axles that come with the differential and should be able to bolt my half-shafts to them. While I'm at it I will need the front differential mount, the mustache bar and the curved bracket that connects the two lower a-arms.

Is that right? Did I miss anything?

-e

[PUSHER]

"Because your modern 240SX LSD uses 12mm gears to secure the ring gear you ought to be looking at getting an R200 rear end from an 84-9 300ZX because the 75-83 R200 have their ring gear attached by 10mm bolts like the R180."

Or you could just use a spacer,12mm outter diameter, 10mm inner diameter, get a couple of these put the bolt through them then through the lsd, then bolt it into the gear.