Kaaz Lsd Clunking

[Busky2k]

Well I've had a KAAZ 1.5 now for quite a while and just got sick of all the clunking. Drives me insane. So I experimented with oils. The clutch packs in clutch LSDs such as the KAAZ rely on the oils co-efficent of friction ie 'slipperyness' to lock up the differential. The stock viscous LSDs do not rely on the diff's oil (they have their own which is a sealed unit) and thus any changes to the diff oil will have no effect. My findings;

-Genuine KAAZ Oil - Very clunky. Chatters even at 60kmh. Hair pulling noise and the car would tend to 'surge' or 'pulse' during low speed cornering under power.

-Castrol LSX - Used as a flush. Less clunky than the KAAZ oil.

-Redline 75W90 - About the same as the Castrol LSX, maybe a hair bit better.

-Redline 75W90 + 30ml of Redline LSD Friction Modifier - Big reduction in clunking. Slight on slow speeds. Smooth.

-Redline 75W90 + 45ml of Redline LSD Friction Modifier - Clunking almost completely gone. Only present on U-Turns. Very smooth.

Redline's LSD Friction Modifier makes the diff oil more 'slippery' which makes it harder for the LSD to engage the clutch packs to lock both driveshafts together. For those who don't want to change their oil you can add the LSD Friction Modifier to your existing oil.

The LSD Friction Modifier is about $22. I would add it to your diff in 15ml increments until you are satisfied. You need to drive the car for a few km for the additive to mix in well. Don't add too much or your LSD lockup may get "too weak" - then you need to drain your oil and start again. I personally prefered it when I added 30ml as I liked to hear the diff working on low speeds still. 45ml it was a bit too 'quiet'.

Also to note, this is why it is important to use an oil that is rated for "LSD" use in the diff for clutch type LSDs. If you add a normal GL5 gear oil such as the Redline 75W90 NS or Castrol Syntrax or Motul Gear 300, they are not appropriately friction modified for clutch LSD operation and the diff will clunk to all buggery as they are not 'slippery' enough. Of course, this is not of any concern to those with the stock Viscous LSD.

[midnight]

so is lsx 90 fine to use in my kaaz? I recently did a change and also found it was abit quieter.

im not really fussed about the clunkyness and I need good lockup for drift.

[PHATR32]

i asssume this goes for any 2 way diff? mine clunks real bad.

dont know what brand it is, it looks stock i think

[Busky2k]

midnight - yep LSX 90 would work fine. I would change it more often though (maybe every 20,000km) being a mineral oil. Castrol EPX/Multitrax etc are not suited for clutch LSD use.

PHATR32 - yep the Redline LSD Friction Modifier should work in your 2 way diff no problem.

Oh btw this is the best way to get the stuff into your diff is to buy this from your local pharmacy (syringe barrel with no needle), then buying 30cm worth of PVC tubing from the hardware store and attaching that to the end of it. Be sure to clean the area around the filler bolt before you take it off. Don't want dirt to go into your diff.

[GTR32GUS]

PHATR32 try the redline oil by it`s self first than if it still clunky try the Friction Modifier

The reason i say this i had heaps of clunking from a few other oils and since i put the redline in it was smooth as

[Al]

Questions:

- You are modifying the slipperyness of the oil, thus the more slippery, the greater the force to lock and the less response from the diff?

- Can this affect premature wear on clutch plates, as they are slipping more?

[Busky2k]

-Yes more force is required by the clutch pack to engage. Thus you need more of a speed differential between each driveshaft before it locks up. Ie on KAAZ oil you only had to turn the steering wheel 90 degrees before it'd clunk to all buggery (ie "tight"). Now I have to do a U-Turn before it does ("loose").

-Im no expert so I can't say but anyone feel free to fill me in. Personally I would guess it wouldn't affect the life of the clutches to a great extent if you don't overuse the additive. Obviously a better solution would have been to adjust the preload of the diff in the first place but I can't see how that would be any different to making the oil more slippery - the clutch slips in either situation. When it was stock, the clunking/grinding is the clutches enganging and disengaging - how could that be any good for the clutches anyway? Its probably worse!

[Nathan_G1]

they clunk, thats what they do.....you cant eliminate it no matter what oil you use, however you say its clunky travelling at 60? is this in a straight line? if so it was installed wrong, you should only get clunkyness when cornering and not necessarily at speed.....

[Ceffy_SA]

Hmm thats interesting, i have a 1.5 way diff in my Cefiro, about a year ago i replaced my oil with some Motul mechanical LSD oil (i think it was the Motul 300 stuff). Before i changed the oil the Diff was less clunky was was getting worse due to old oil, so i changed it to the motul stuff without using any friction modifier. After the oil change the diff became alot more "clunky" than before and alot tighter too, interesting thing is that after about 20-30mins of driving then diff warms up and almost all "clunky'ness" goes away and it behaves very tight.

[Al]

Hmm thats interesting, i have a 1.5 way diff in my Cefiro, about a year ago i replaced my oil with some Motul mechanical LSD oil (i think it was the Motul 300 stuff). Before i changed the oil the Diff was less clunky was was getting worse due to old oil, so i changed it to the motul stuff without using any friction modifier. After the oil change the diff became alot more "clunky" than before and alot tighter too, interesting thing is that after about 20-30mins of driving then diff warms up and almost all "clunky'ness" goes away and it behaves very tight.

Well i have had my Kaaz for 6months and have changed the oil twice, each time with Kaaz oil. After each change the diff felt better. Mine only clunks at low speed (10-30km/h) round corners or round-abouts, but after 30min of driving it very rarely clunks.

[Busky2k]

Interesting. For me the hotter the diff got, the more it clunked. On a hot day it was a nightmare. When the diff is cold it was silent.

[Al]

Interesting. For me the hotter the diff got, the more it clunked. On a hot day it was a nightmare. When the diff is cold it was silent.

This may not be relavent: Did you do the fig. 8's for 20mins, to bed in the diff?