Kaaz LSD break in?

Question and then explaination: Kaaz says that their LSD's need to be broken in by driving the car 1/2 hour in a figure 8, I can almost feel the pressure drop nor do I have a good location to accomplish this. You guys think this is really needed? am I going to cup the clutch packs and ruin the thing like they say?

The Kaaz is going into a coverted awd to fwd subaru trans for my '93 soon to be group 2 Impreza fwd. The clutches on the fwd trans are weak and there are no final drive options for the fwd gearset so I am changing out the whole thing for a awd clutch, LSD and 4.44 final drive. should be fun.

Here's a pict of the conversion: a fwd rear case won't fit over the 5th gear shift fork so the center case is going to get blocked off at the back.

---

-KTurner
Stomp down on the exhilarator and hold on to the wheel.

Well I would recommend at least giving it a recent stab. I've done it in grocery store parking lots, you don't need a lot of room.

You don't need to do a full thirty minutes, I broke mine in perhaps about 40 figure eights.

I've heard from folks that skip it that they get excessive clutch chatter, etc.

I think also what is really important is to use a good transmission fluid with a friction modifier. The stuff KAAZ sells is great if you're using it in a rear end, but if it is in a transaxle it really too thick to lubricate properly. I've had problems with the synchros on the Hondas when using KAAZ's fluid. Now I use Redline (forget what weight) with a friction modifier--so far so good.

Although honestly I'd chuck the thing and go with a welded. They don't come preloaded high enough from the factory to drive out on a busted driveshaft, and I'm thinking by the time you get it tight enough you're just driving a welded differential anyway.

Coming from the drifting side of life, yes. Many people have whined about their new LSDS suddenly dying... and when asked if they broke it in, they said no.

Half an hour of figure 8's isnt that bad.

---

Welcome to the cult of JVL drink the koolaid or be banned.

krisdahl Wrote:
-------------------------------------------------------
> Well I would recommend at least giving it a recent
> stab. I've done it in grocery store parking lots,
> you don't need a lot of room.
>
>
> Although honestly I'd chuck the thing and go with
> a welded. They don't come preloaded high enough
> from the factory to drive out on a busted
> driveshaft, and I'm thinking by the time you get
> it tight enough you're just driving a welded
> differential anyway.
>
>

OK, looks like the break in will have to happen somehow. Other concern is the car isn't registered at the moment... I'll figure something out.

Have a welded diff in the transmission right now, works pretty good. How do you change the preload? The discs are already ordered for the max number of friction surfaces, do I have to track down a big conical washer?

current clutch pack:

---

-KTurner
Stomp down on the exhilarator and hold on to the wheel.

do it or don't.

Just - do not drive at freeway speeds without the same tire diameter on the axle. (you'll be able to tell. the car will pull one direction while getting on and off the gas. your diff will hate it)
you could break it in by driving around the block if you wanted to, in opposite directions.

it sure is nifty doing the big skid pad circles, feeding in and out the power, feeling when and how it tightens up. just do it symmetrically.

if the rest of your gears are in the same box as the diff, it might make sense to replace the fluid after break-in.

---

"I put the hurt on dirt" - adam crane
http://CraneRallyCrew.com
corolla gt-s "Patches"
Op: S.S.

I drove around my large neighborhood in the numerous courts, doing clockwise and then counterclockwise routes. I used the original transmission non-Kaaz fluid for break-in for about an hour.
I got a lot of strange looks as I drove by, and some nasty glares from some of the stay-at-home-moms in the yard.
I changed to the Kaaz fluid after the break in, all has been well.
The Kaaz clunks when cold, and moving slow, but sure hooks up on course where it counts.

Yeah exactly. Or actually if I recall it already has a conical washer, you could just shim on the other side of that--I think that is what we were going to do.

I called KAAZ a while back and asked them for what kind of shims I should be using, and if they have any idea of 'how much' I'd need to get it to be able to drive out on (JVL says about 150 lb-ft of breakaway). They told me "If it is not hammered already, it should do that stock". Well, I can tell you with certainly a brand new KAAZ can't.

I'd try getting ahold of them and ask what they suggest for shimming.

I'm probably just going to drop the KAAZ out and put a welded unit back in. I don't want to DNF a single rally more because of a broken CV.

Update: got in touch with Kaaz USA and they were pretty helpful. They are saying the stock setup is 90-100 ft/lbs for the DF2015 that I have. The suggestion was to shim out each side 0.1-0.2 mm for an unknown, possibly 50ft/lbs gain (shims would be homemade) or to add in a single thicker disk on each side for a 20-30ft/lbs gain. Both are options. Figure the car weights 2200lbs and makes 110ft/lbs on a good day (yes I am using an ej18).


Otherwise made friends with local big box parts store, He said to come down and light'em up!

---

-KTurner
Stomp down on the exhilarator and hold on to the wheel.

Good info, may try doing that myself, see what happens.

Good luck making shims that are between 3 - 7 thousandths of an inch thick. Sounds like a pain in the ass.

.1mm??? Why not just pee on it? It would probably have the same effect.

Can you take pictures of your diff so those of us who don't have one to compare to can see what you're talkin' here?

---

Michael LeCompte



Edited 1 time(s). Last edit at 09/07/2008 12:17AM by pikespeakgtx.

Would differential set-up shims be too flimsy?

Looking them up on Summit's site, I see that you actually can buy "differential clutch pack shims". Not expensive, either.

---

Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

pikespeakgtx Wrote:
-------------------------------------------------------
> Good luck making shims that are between 3 - 7
> thousandths of an inch thick. Sounds like a pain
> in the ass.
>
> .1mm??? Why not just pee on it? It would probably
> have the same effect.

Since you obvisously have never re-shimmed a diff, why don't you withhold making judgements about what a shim will affect the preload.
>
> Can you take pictures of your diff so those of us
> who don't have one to compare to can see what
> you're talkin' here?

Jeeesus, see?

Seriously, why poo poo on an idea when you don't even have an idea of what the guys are talking about?


>
> Michael LeCompte
>
>
>
> Edited 1 times. Last edit at Sep 6, 2008 by
> pikespeakgtx.

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Chill out John... I'm not making judgements or poo pooin

I'm saying I have no clue and I want to see pics so I can see whats goin on.

How do you home make a hardened steel shim the width of a human hair?

---

Michael LeCompte



Edited 1 time(s). Last edit at 09/07/2008 12:04PM by pikespeakgtx.

You buy some 0.001" thick 302 stainless steel shim stock (8"x12" is about $6) and you cut it out with a pair of heavy scissors. At about 0.003" thick you have to change over to using a nice new/sharp pair of sheet metal snips.

Alternately, you measure what size you need and use this search engine to see if they already make it:

http://www.bokers.com/

pikespeakgtx Wrote:
-------------------------------------------------------
>
> Can you take pictures of your diff so those of us
> who don't have one to compare to can see what
> you're talkin' here?

> Edited 1 times. Last edit at Sep 6, 2008 by
> pikespeakgtx.

like this?


or this? one side is complete... shim would go between cone spring and clutch disc. big washer looking thing is cone spring

---

-KTurner
Stomp down on the exhilarator and hold on to the wheel.