S15 differential, HELP!

[2stepGoesPowPow]

A local shop is selling an S15 diff, I need it for my 2jz swap in my S13 and from my research I need the one with the 4.083 final drive, the shop doesn't know what the final drive is and I don't want to buy it for nothing can anyone verify from these pictures I took of it? Or know a way I can tell? Thanks

[future]

Like I told you in pms. You need to open the diff

[dudermagee]

Pretty sure an s15 diff housing will not bolt up to your subframe without modifications.

The internals will swap out though.

[2stepGoesPowPow]

Originally Posted by future

Like I told you in pms. You need to open the diff

I went to see the diff at a jdm warehouse, they just got a s15 rear subframe in and they were willing to part the diff out of it for me but not willing to open the rear plate

[oni jake]

Pretty sure the housing is the same. I've heard of people dropping S15 subframes into S14's all the time with zero problems. Might have a problem with the front two bushings, but shouldn't be bad.

Gear ratio depends if it was a manual or automatic car. Straight from the FSM

Applied model M/T / A/T
Final drive model R200H / R200V
Gear ratio 3.692 / 3.916
Number of teeth 48/13 / 47/12

[oni jake]

YAY! Forum removes spaces to accurately display a grid.

[2stepGoesPowPow]

I could probably get away with using the 3.9 final drive diff but the guy said its the diff from a 6 speed not an automatic

[jr_ss]

You'll be fine with the 4.083 ratio. The only way to tell is to crack the case. I'd want to crack it more so to verify that it is an LSD of some type and I'm not getting the shaft.

You could pick up a Q45 3.6 VLSD but then you have to swap axles. Another option is to grab a 350Z diff and mod your subframe to accommodate, which will also hold more power.

[oni jake]

Originally Posted by 2stepGoesPowPow

I could probably get away with using the 3.9 final drive diff but the guy said its the diff from a 6 speed not an automatic

The 4.08 is the most common and not at all hard to find. I believe they are sold in every USDM open diff S13 and S14 chassis.

I guess it really depends how much money he wants for it. 3.6 final drives sell for quiet a bit. They're perfect for N/A KA's. Plus, having options is always a good thing for when you go to the track.

[Xicor01]

I have a Q45 and the Q45 driver side axle for sale. so all you would need is the z32 driver axle. the q45 is a 3.54 VLSD and is recommended for the 2jz swap

[2stepGoesPowPow]

Originally Posted by jr_ss

You'll be fine with the 4.083 ratio. The only way to tell is to crack the case. I'd want to crack it more so to verify that it is an LSD of some type and I'm not getting the shaft.

You could pick up a Q45 3.6 VLSD but then you have to swap axles. Another option is to grab a 350Z diff and mod your subframe to accommodate, which will also hold more power.

i have the 6 bolt axels, are those from S14's? i think someone told me S13's usually come with 5 bolt axels? also I'm just looking for a relatively bolt in install, also when i first bought my car the previous owner said it had a "R32 VLSD" i swapped it out for a welded back when i had my SR in the car. i wonder what the final drive is on that thing... lol

[Guilty1s]

If it isn't the drive ratio you want, all you would have to do is put your ring and pinion from your open 4.083 pumpkin and use the differential from the s15 inside. The diff has nothing to do with gear ratio. It is all in the ring and pinion which are almost all swappable throughout the past few decades of Nissan cars.

But.... One way you can tell is spin the tail shaft and compare it to how much it turns the axle shafts.

It should take about 4.083 turns to make turn the axle 1 time... do it multiple times and you can be more sure.

If it take 20.4 turns to turn the tail shaft 5 times it is a 4.083
If it take 19.5 turns to turn the tail shaft 5 times it is a ~3.9
If it take 17.5 turns to turn the tail shaft 5 times it is a ~3.5

[jr_ss]

Originally Posted by 2stepGoesPowPow

i have the 6 bolt axels, are those from S14's? i think someone told me S13's usually come with 5 bolt axels? also I'm just looking for a relatively bolt in install, also when i first bought my car the previous owner said it had a "R32 VLSD" i swapped it out for a welded back when i had my SR in the car. i wonder what the final drive is on that thing... lol

Yes, S14/S15/J30/NA Z32 and possibly a few others had that pattern on the axle output shafts.

Not all S13's have the 5 bolt outputs.

[2stepGoesPowPow]

Originally Posted by Guilty1s

If it isn't the drive ratio you want, all you would have to do is put your ring and pinion from your open 4.083 pumpkin and use the differential from the s15 inside. The diff has nothing to do with gear ratio. It is all in the ring and pinion which are almost all swappable throughout the past few decades of Nissan cars.

But.... One way you can tell is spin the tail shaft and compare it to how much it turns the axle shafts.

It should take about 4.083 turns to make turn the axle 1 time... do it multiple times and you can be more sure.

If it take 20.4 turns to turn the tail shaft 5 times it is a 4.083
If it take 19.5 turns to turn the tail shaft 5 times it is a ~3.9
If it take 17.5 turns to turn the tail shaft 5 times it is a ~3.5

thanks a lot for that info thats pretty smart, im gunna post in the 2jz swapped s chassis thread, a bunch of 240 vlsd's have the 4.08 ratio final drive i dont get why they dont just use that... like this

JDM Nisan Silvia S13 Viscous LSD Rear Differential 4.1 240SX 180SX SR20DET VLSD | eBay

[oni jake]

Isn't the pinion from S15 pumpkins different from all the others because of the speed sensor? If so, it's not as simple as swapping out.

[2stepGoesPowPow]

i pretty much got all my questions answered, i dont really NEED an S15 diff. pretty much anything 3.5-4.08 ratio, id use a J30 but i want something w/ 6 bolt shaft's, but i heard swapping the diff shafts are easy? because i have my spare vlsd i could swap the shaft's from.

[oni jake]

Cool, glad you got it situated. Keep the world informed which one you like and where you're using it.

Swapping output shafts are cake. Beat them out with a hammer or use a pry bar. It doesn't require alot of force.

[Croustibat]

I just got an S15 pumpkin to fit on my s13, so here are some more infos:

1/as stated above, there is no 4.xx drive on them. 3.7 on the helical diff (manual 6 speed), 3.9 on the VLSD diff( auto gearbox) .

2/ the pumpkin fits the s13 subframe, you have to swap the backplate though. Bolt holes are not the same so you may have to replace the bolts. If you fit an S14 subframe, you also need to get all the suspension arms, they are not the same. S14 subframe is told to be better too (and are the same as the S15 ones, maybe with less bracing)

3/the S15 helical diff is a really good addition to any grip car, but it is not worth it on a drift car. seeing as you are fitting a 2jz in an S13, the rear will be all over the place (unless you modded the firewall to get a foot of your engine in the cabin) , so maybe that is not what you want.

I did not know these gearings were so pupular in the US. I will try the S15 3.7 gearing first, but my tuner also has a 4.1 one, and i already own a 3.9 one as standard (S13 w/ca18det have a 3.9 in europe)

If someone want to buy my original 3.9 and maybe my 3.7, you can drop me a pm (although shippng price might be an issue as they are heavy and i live the other side of the atlantic).

[OutToWinPAHC]

When I did it I used a S14 case, input pinion and ring gear with the nismo bolts. This eliminated the Diff speed sensor, and was bolt in. I used Energy suspension bushings over solid (order for Z32). No axles, no new drive shaft and this was in my LS6 S13

[jr_ss]

Originally Posted by oni jake

Isn't the pinion from S15 pumpkins different from all the others because of the speed sensor? If so, it's not as simple as swapping out.

It's identical to the S14 ABS housing... Nothing special about it.

[future]

Some s13s have five bolt, some have six

Same problem with j30 and q45. If you get on from the right year it bolts right in no problem

[simplistek]

Delete. My bad.