OS Giken Super Lock LSD Install
 

If you were ever wondering what it takes to install a OS Giken differential, here you go :) This isn't so much a howto but a general guide to be used as a reference. Not a terribly difficult job but if helps to be familiar with how your car comes apart.

[ame]http://www.youtube.com/watch?v=YQbHA6zT59Y[/ame]

I saw this yesterday and asked the discord what exacrtly is better about this.vs the OEM? Just stronger and lighter?

You didn’t mention any gasket when you were putting the cover back on. Omission? Or is it not necessary there after?


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I show the gasket going on in the video. It is the gasket from DIF/FRsport.

https://frsport.com/dif-10590-differ...asket-fr-s-brz

Now that you mention it, I think I forgot to add that to the video description.

an OEM Torsen LSD becomes open when one wheel loses traction or is lifted off of the ground.

The OS Giken, or similar clutch type LSD, can physically lock the rear wheels together, so that you have to either lose traction with both wheels, or you don't lose traction at all, in the rear.

This can have many effects, but the biggest ones are that it makes the rear more predictable, since it behaves the same every time, regardless of condition, and can stabilize the car further under braking (or destabilize the rear, if you choose to set the diff up that way, e.g. for drifting).

For cars set up for grip, side effects include being able to recover spins/slides from much greater angles, and making the rear much more difficult to kick out under grip circumstances. In a car set up for drift, the LSD makes the rear end sustain rotation predictably, instead of randomly hooking one tire up and causing a push.

You can @ me on discord, or I will never see it.

I would go read this to start: http://osgiken.net/c-1280300-limited...-lock-lsd.html

CSG Mike: what should be kept in mind regarding maintenance / long mileage daily driving usage with such clutch type lsd-s? And do they last long?

It varies by the setting of the LSD and the application. I wouldn't be able to give you a blanket answer.

OS Giken LSDs are meant to last the life of the car.

AND - the clunking and associated weird noises with parking lot turns etc., that are very disconcerting for passengers thinking the car is breakin up -lol:eyebulge:
:cheers:

There is no clunking, popping, or unusual noises with an OS Giken LSD that is properly tuned for the car.

I run an ATS LSD on my car, and most people never realize I am running a clutch type diff when they sit in it.

Using an off-the-shelf LSD is like using an off-the-shelf tune. It's probably better than nothing, but the LSD is definitely not a one-size-fits-all. Having one configured to match your car/needs will yield significantly better results.

Nice to know those 2 diffs have no scrubbing, clunking etc. associated to lockers.

@CSG Mike, I wanted one, but my shop talked me out of it saying overkill for my weekend toy since I no longer track. Would a dialed in OS Giken LSD be beneficial on a weekend canyon carver? Sure sounds better.

They both can. It's really dependent on the tune/setting of the diff.

Likewise, this also applies to Cusco, Tomei, Kaaz, etc.

Beneficial? absolutely. Worth it? Hard to say. It's subjective on the worth it end.

I would personally get a LSD before coilovers.

Mine clunks at very slow turning speeds. It is a custom tuned OS Giken for autocross. Everywhere else it makes no noise

i thought that is what all LIMITED slip diffs did, which is why they are limited and not locking. have i been wrong this whole time?

Yes.

@justinco, congratulations - I think you’re going to love the differential. My OS Giken 1.5 way LSD was an awesome upgrade, and right up there with my ACE Type-A 350 header and my MCS 1WNR single adjustable coilovers as one of my favorite modifications so far. The OS Giken unit just transformed the back of the car and made it so much more fun to drive. As for modifications, you and I have travelled similar paths, huh? I haven’t made it through the video yet so cut me some slack if you mentioned this, but did you go with 1.5 way unit, too?

It’s cool you’re working so closely with the guys at @CounterSpace Garage - I did the same, and they were fantastic to work with and have given me a ton of support long after the sale.

The twins with lockers set up for tracking that I have been in clunk at sharp slow turns, less so when warm, and are fantastic on the track compared to stock.
Much less tire scrub etc. than with the old clutch, hydraulic and gear lockers I use to race with off road, before the Jeep Cup days.
:thumbsup:

Watched with popcorn ㅋㅋㅋ

Going to watch this later.... for education purposes:popcorn:

Justinco, any feedback on the LSD over the past few months of driving? How it’s behaved differently than the Torsen in AX, track, and street situations? Thanks!

Just to followup on this. Once I switched to the OS Giken OS250R fluids the low speed clunking went away. I had Motul fluids in there before for the first 1k miles, per OSG.

The biggest difference I have noticed (autox and track) is the car is much more smooth and controllable on corner exit power down situations. It will slip and slide (tire grip), but very predictably while still accelerating. Versus the torsen, where grip would break away more abruptly and be harder to keep under control. No real difference on the street cause I drive like a grandma.

@justinco You mentioned the backlash with the ring gear and pinion gear, but were you also told that you didn't need to measure the bearing preload and/or adjust shims (that you called washers in the video)? I've been bitten by not checking preload and adjusting shims!

That's right. Per OS Giken it is a drop in upgrade for our cars. Obviously if something is horribly out of wack you don't want to go forward with the install.

Really curious how this would change the corner exit dynamics in a track setting. I've been thinking about upgrading the diff in the next year or two. Sounds like it makes a big difference!

Hey Justin, did you have to change the side bearing shims at all? I'm assuming not by the video. I'm actually installing the diff into a 3.91 rear diff from an IS350 which is the same as in the BRZ, and when re-installing the LSD the shims seem a bit too tight. I'm afraid if I drive the one into place with a drift I won't be able to get the diff back out. I pressed the bearings on and they are definitely pressed on all the way.

The stock non-LSD in the unit wasn't too hard to remove it just kind of fell out so my I ordered 4 smaller shims, 2 for each side and then I'll measure the backlash.

Now that I'm writing this I should really just measure the width of the two units and figure out if there really is a width difference or not.

Everything I read including other install articles for the Giken show and mention that backlash is checked and may need adjustment yet you installed yours without, apparently, checking backlash whatsoever. Is there any whine or noise, apart from chatter when cornering, at all? Is it as silent as the OEM? Tossing up between the Giken and the Cusco but if the Giken is a DIY v Cusco being a pro instal job, I could spend the extra the on buying Giken and instal myself.

Also; does the Giken negate the need to use Whiteline style diff inserts to stiffen the mounts? Now that I think about it I think I saw you had them in fitted in your car during the Giken install. Is the NVH any worse with the Giken and Diff mount inserts?

Nope. You still need to stiffen up the diff mounts to lessen how much it moves under load.

I did not.

So keep in mind my install might not apply to absolutely everyone. If it seems out of wack, you should probably go through the full process to be sure.

My OS Giken contact (who is also a friend, and is also on these forums) instructed me to drop it right in. I have other friends (also on the forum) who have swapped the OSG diff in and out multiple times and did not have to do anything other than pull and replace. YMMV.

My diff is quiet, there might be a little whine when slowing but that's about it. It clunked A LOT with the Motul fluid in there, nice and quiet once switched to the proper OS 250R.

The NVH did not change after the OSG diff was installed. I still recommend the diff inserts regardless of what diff you have in there, it makes a big difference.

really fucking dumb question, how beneficial would this be in winter weather? took my car to an empty lot to play around in the snow today and was thinking on the way home good thing i didnt get stuck. saw this thread and wondered.

Your stock Torsen is just fine.

luckily im not dumb enough to put that to the test tomorrow

I had them in and took them out due to NVH thru the drive train but I have the subframe inserts, gearbox inserts, shift springs, and the IRP shifter all adding to it...

Yes they make a huge difference and if you can put up with the mild side effects are well worth doing.

It’s been written elsewhere here, but a lot of us including myself have left out the bushings (of the total Whiteline setup) closest to the head of the vertical diff bolts. It surprisingly removed a lot of the noise for me. Another one for me was the trans insert. It wasn’t WL brand, but noise went down after I replaced it with an STI mount.

Justin, do you have anything positive or negative to say about this gasket? I ended up ordering one and I haven't heard of anyone else using it.

I'm currently rebuilding a dif for friends who have a local shop to me and the previous builder used that gasket and it worked great. I even ordered the same thing for when I'm done with this rebuild.

It worked perfectly fine!

how much NVH do you feel that they added?

So the IRP shifter is STX legal?

Anyone here know how these OS Giken's come straight from the factory? I haven't found much info on it as a 1.5 way or 2 way and there aren't any specs on it. When I contacted OS Giken USA, they told me to send one in to get tuned for my specific application. I'm looking to drift with it. Any info out there or resources you've been able to find?