180sx VLSD question

[sjbsuperman1425]

i bought one, its a 6 bolt and i know it'll bolt up. For some reason, i was bored and searching the web on the swap and came across conflicting information.

1).I've read the 180sx with the CA in it has a final drive ratio of 4.36 and the 180sx with the SR has a final drive ratio of 4.08. Is this correct?

2).Do the output flanges (5 or 6 bolt) have anything to due with the drive ratio? (example - did 4.36 GR only come with 5 bolts)

I'm not really worried about it other than my gas mileage haha, but I'm just curious. Thanks.

[ILoveMyRHS13]

CA 180sx - 4.36NA SR 180sx - 4.36SRDET 180sx - 4.08

[sjbsuperman1425]

anyway to differentiate the three without actually counting the ring/pinion teeth?

[Bumnah]

You must count the threads or read the stamp on the ring/pinoin.

4.36 pinion has 48:11 stamped on it.

48/11 = 4.363636363636364

[sjbsuperman1425]

count the threads, can someone explain please?

if indeed it is a 4.36 and say i wanted the 4.08 back, i could switch the ring gear from my open to the VLSD correct?

[OutToWinPAHC]

Only if the pinion teeth are the same.

zerothread/228683

[sjbsuperman1425]

thanks for the link, i've been searching all day and didn't find that. is the ring gear only stamped with the ring gear count or does it have both the ring gear and pinion gear ratio stamped on it?

according to my math the stock 89 S13 is a 49:12 (4.083)..so thats a negative on switching the ring gear if its a 4.36. I could switch the VLSD internals over to the open diff pumpkin and use the stock ring gear and retain the 4.083 right?

also, from what i've read throughout the day is that the 4.083 JDM VLSD's were ONLY 5 bolts. Can anybody confirm this?

Thanks alot everybody, I've been searching for answers all day since 1pm.

[Bumnah]

Get a 4.36 rear diff, it's way more fun than the 4.08. Only sacrifice high way speeds .I keep it at 70 mph max. It's worth it for the acceleration gains.

[sjbsuperman1425]

its already on its way lol. I guess i'll know what it is for sure when i take the cover off to replace the gasket. Thanks.

[sjbsuperman1425]

well it is a 4.36. the guy i bought from confirmed it.

im going to try it out, see if i like it, but if not, i can just swap the differential into an open pumpkin with the open diff. ring gear can't I and VLSD output shafts?

[Bumnah]

If you're not keen on taking the diff cover off, I wouldn't bother trying to swap over ring and pinions. You have line and have proper clearances or it'll whine.

Stick with the 4.36, it's a pretty tame setup.

[sjbsuperman1425]

i know someone that will/can do the clearances if i swap it over, but I can do that correct? Use the JDM VLSD and output shafts with the open diff pumpkin, pinion, and ring gear?

what RPM are you running at 70mph with a 4.36?

[sjbsuperman1425]

bump.

i was told by someone on Zilvia that the open diff ring gear is "thicker" than the JDM ring gear, so it wont work. But that doesn't make since to me since they are both R200 units.