S15 HLSD install How-to

[MakotoS13]

This is for all those kids wanting the helical goodness of a HLSD without spending a ridiculous amount of cash on the quaife. here's what you need:

-S15 differential
-S15 output shafts (both sides)
-80W-90 gear oil (2 quarts)
-RTV
-brake cleaner
-brute strength, lift, or plenty of assistance friends

http://www.makotoseven.com/240/level3/hlsd2.jpg

tools:

-floor jack (one with a very wide seat is prefered)
-jack stands
-12mm wrenches (2)
-14mm wrenches
-17mm wrenches
-vise and breaker bar or impact gun

1- okay, so get the car in the air.
2- drop the right side of the rear sway bar (12mm/14mm)
3-remove the 14mm nots from the driveshaft (4 nuts)
4- remove the 12mm nuts/bolts from each axle (6 per axle, 12 total)
5- remove the four rear nuts from the differential cover that's mountedto the frame (17mm)
6- remove one 17mm bolt from the front of the differential where its mounted to the subframe
7- place jack under pumpkin and get it to the right height
8- remove last 17mm bolt
9- DO NOT LET THE PUMPKIN FALL ON YOUR HEAD. IT HURTS... A LOT.
10- lower the pumpkin on the jack and get that hoe to a work bench
11- you'll want to drain the fluid before removeing the diff cover
12- remove the 8 14mm bolts on the diff cover. there's a place to pry it up using a flathead screwdriver.
13- use a flathead screwdriver to hammer out the shims on each side

****THIS NEXT PART IS THE MOST CRUCIAL ONE****

14- make absolutely certain to note which side each shim goes on. if you lose track of this you'll kill your ring gear, diff, and pinion gear. you don't want that. take a photo, i dont care, just keep it all seperate and make sure you know exactly which side they go on.
15- remove the differential
NOTE: dont worry with the pinion gear, screwing with that is trouble.

now clean all the parts using degreaser and brake cleaner. i pressure washed everything because im insane.

16- use an impact gun or a vise and gigantic balls to remove the 17mm bolts from the ring gear.
17-swap the ring gear onto the S15 diff making sure the holes line up and torqing the bolts down in a criss cross pattern.
18- replace it all in the pumpkin and hammer the shims into place

http://www.makotoseven.com/240/level3/hlsd1.jpg

19- remove the old gasket from the diff cover
20- RTV the heck out of the edge of the pumpkin for the cover.
21- put the output shafts in.

NOTE: one output shaft is smaller than the other. you can tell which side its supposed to go on by eyeballing it and if you can't... hammer it out and try the other way. if it takes more than two tries on this part you're doing something horribly wrong.

22- reverse the process to get her mounted in and go do some donuts.

[datboibrad]

your gay doug that is all

seriously tho good job and nice write up. pics > *

[OptionZero]

Damn good write up.
I paid a shop to do it becuz some idiot bolted my bolts on too tight with an airgun.

[SochBAT]

Cmon Dougie! You forgot! The side with the extra shim gets the longer output shaft! When installing my diff, i used brakeclean on the inside of the bare pumpkin, and had it sit. Cleaning out all that gunk and crap isn't needed, but if you like it clean, and having that piece of mind, go for it. When installing my welded, i used colored caliper paste/disk quiet/jizz to make sure that the teeth and gears matched up correctly. You'd normally want the teeth to meet in the middle of the spidergear, for perfect contact and operation. If you've got it mashing the closer edge of the gear, it'll end up grinding it down to shit. If its not matching up right, try using a flathead and adjusting how the diff sits in the housing etc etc.

Do it right the first time, instead of going back, reassessing the problem, screeching like monkeys, and crying.

I commend you on the write up tho.

+1 for Doug, the man with the answer to Hurricane Katrina.

[WILDACEX187]

this is an awesome write up but i got one question. on 17 u said swap the ring gear onto the s15 diff. i got a little confused. heres a pic of wat i think u mean.

[wootwoot]

I was just wondering what fluid you are actually using and were you surprised to find out the noise the diff makes? It is super smooth and I love mine so much but there is some slight clunking if you are on/off the throttle at a given speed, it scared me at first but I was told it was normal. I'm currently running Royal Purple 75w90 but want to switch to something a bit heavier, maybe a Redline fluid since the thicker it is the easier the diff locks. How much did you get yours for to boot?

[TheTicTac]

this is an awesome write up but i got one question. on 17 u said swap the ring gear onto the s15 diff. i got a little confused. heres a pic of wat i think u mean.

The part where you labeled diff is actually the ring gear.

[WILDACEX187]

can somebody explain procedure 17 for me if possible then cuz i didnt quiet understood it.

[NismoSilvia270R]

can somebody explain procedure 17 for me if possible then cuz i didnt quiet understood it.

IN YOUR PIC: the thing labeled "diff" is the ring gear. the silver part that is just to the right of it is the flange of the diff.

step 17 just means bolt that "diff" (ring gear) to the silver flange on the diff(just to the right).

note the bolts.

and the pattern he talks about is like when you put on your wheels. dont torque in a row, skip over one.

MY PIC
http://i9.photobucket.com/albums/a53/nismosilvia270r/hlsd1.jpg

i just made this, maybe this is the criss cross pattern Makoto used?
http://i9.photobucket.com/albums/a53/nismosilvia270r/jcb890.jpg

[WILDACEX187]

oh ok, its more in the clear now. thanx

[SochBAT]

When installing the ring gear onto the diff, i just bolted in one, skipped 2, bolted, skip 2, etc etc.

And when aligning my diff for backlashing, i just used a screwdriver near the bearings to adjust it slightly, and then bolted it up nice and pretty.

[elphkotm]

Nice writeup. Now I'm more sure than ever that I'll be paying someone to do mine :D

[skiboard06]

where did u get the s15 diff to use for this install price?

[SochBAT]

e, bayyyyyyyyyyyyyyyyyyyyyyy!!!

[S14DB]

****THIS NEXT PART IS THE MOST CRUCIAL ONE****

14- make absolutely certain to note which side each shim goes on. if you lose track of this you'll kill your ring gear, diff, and pinion gear. you don't want that. take a photo, i dont care, just keep it all separate and make sure you know exactly which side they go on.
15- remove the differential
NOTE: dont worry with the pinion gear, screwing with that is trouble.
Yeah, then you end up IMing me pissing your pants like a bitch.
:Ownedd:

[derk]

for you guys running S15 HLSD's with S13 ring gears on them... did any of you notice that the S13 ring gear bolts are actually thinner than the s15 ones?

did you guys just bolt the s13 ring gear on with the smaller bolts anyways? cuz the HLSD housing, where the bolts go through on the S15 hlsd has a larger I.D than the S13 open or vlsd, if you just use the S13 bolts theres about 1mm of play between the bolt and the diff housing...

anyone here running S15 hlsd's have a problem with the bolts from the ring gear snapping off?

[ryan hagen]

nismo makes special bolts for doing that swap with fat shanks. anyways, alot of people just run it, i ve had mine in for 2 year no problems other than with solid sub frame mounts its loud as hell, you hear gears whineing all the time, i change the fluid every 3 or 4 months and no metal on the magnet yet.

theory goes the ring gear is centric to the carrier itself, and when you torque the bolts down they dont slip, or shouldnt.

[MrChow]

^^^ 3 year old post and the last post was last year...

Don't bump old thread

[ryan hagen]

i clicked on it on the home page of the forums, weird, never checked the date, and it wasnt part of a search how it get back up top? and anyways i left good info for anyone searching it. i dont have the part number for that bolt kit but its available.


^^^ 3 year old post and the last post was last year...

Don't bump old thread