A-lsd

[L33igh]

Hi all! Hoping someone can shed some light on some problems I have with my 33's diff.

I have one of the supposedly rare, A-LSD lights in my dash and a large hydraulic unit residing behind my drivers side rear quarter panel. I am told that this is an identical unit to that found in a v-spec GTR...???

As I am new to this site, could somebody tell me where I might find some info on these set ups,either here or elsewhere? My diff (in S2 R33) open-wheels without any hint of LSD operation...truely frustrating.

Any help appreciated, I have my theories but am open to better wisdom.

Thanks

[MotoMan]

There is very little information regarding the ALSD...

If its open wheeling i guess you could try replacing the Oil in the diff.. and the fluid in the bottle (rear qtr panel)

I have the same diff in my car.. Can you hear the loud whine of it priming when you start the car? (much louder than the fuel pump)

[L33igh]

I have recently changed the fluid in the diff and also in the resivior in boot, but no cookie. Yes I do hear it priming, from what I can see there must be a solenoid that distributes fluid into the diff from a pressure chamber and hydraulically actuates the diff center, much like a clutch. I may be wrong. The diff has never locked in the 6 months I have owned the car. The fluid that I drained out was clean, no filings or burn't smell, which makes me think that it may not have worked for some time. Im lead to believe that my car was owned by a japanese family before it made its way here and I bought it after just 6 weeks in Oz.

Im hoping that the diff is in A1 condition and that fixing the solenoid will cure my problems.

How predictable is your diff MotoMan? is it any good as a mild street/drift diff or am I wasting my time trying to fix it?

[mattymagoo22]

hey man same deal in my car. the a-lsd light has never come on the slip light does though when on IGN reds. I jacked my car up and and choked the N/S/R (passenger rear) with a bit of wood between the tyre and the ground. before you do this make sure you wont hit something or someone if the car lurches forward, i then started the car and slowly eased off the clutch in 1st gear. it spat the wood out no probs. I did the same for the drivers rear and the other wheel just spun freely and the wood stayed put. Now I assume (have been unable to find wiring diagrams or any info on how the system works from nissan and not oldmate nowitall) that the system uses the ABS sensor to detect wheel slip and seeing as my A-LSD light nver worked I though it may be electrical that was letting me down, so I manually operated the pump with the wood still under the wheel ( I had switched the car off thn on again to clear the ABS light) and the pump running which should have locked the centre of the diff (yes it is hydrulically actuated by feeding oil pressure into to actuators either side of the diff housing) but the wheel spun freely so it was at that stage I bled the system (one nipple on the pump and one on the pass side on top of side plate on diff) to make sure there were no airlocks in the system, you're supposed to use a gen nissan oil that is yellow ,z something or other, in colour, i just used an equivalent oil) still no luck. Then I changed the diff oil (inside the diff) to an oil that was for LSD's and now its a schizophrenic limo (duals up 1 minute then single wheels) I changed the oil at a different time so when i was testing with the car jacked up this change wasn't made, I only found that it limo'd up when doing burnouts more often than before, it still limo'd on static burnouts but try to rip helis or get some good drift going and it packs it in. so I assume that someone may have put an incorrect oil in it at some stage even though it says use LSD oil (that or it had its ass thrashed back home) and the clutches inside have worn out. I have heard someone with the same problem had there diff pulled out and checked and the diff guys said it all looked ok. the only thing I haven't done is check the line pressure to the actuators on the sides of the diff I was thinking on manually applying pressure to them but at this point I just was fed up with it and am trying to track down a mech LSD for it... the saga continues.

Turns out it IS the same diff as the R33 GTR V spec, not the 2-way mech LSD ,but the shitty Active LSD fitted to the V-specs, and the tomeis, and KAAZ's don't have a part listing for this particular diff. Sooooo, If there is anyone who is an import diff expert I'd like to know if the diff that fits a normal R33 vicous would fit into this housing withou needing any mods as I'm haven't done the research and can't understand nismo part guides( ... read don't bother looking) pro, GT pro 240sx so on so forth. I just want a good limo. I was getting close to measuring up a mates with the normal viscous and just buying one of them with the limo in it from jap land and swapping the whole unit but then I heard something about half shafts being different..... I'm rambling

So yeah, not much fun. But one day I'll get my act together and get a diff as I'm over trying to fix mine. If you happen to get yours going PM me and let me know the details all the best mate.

Cheers Matt.

[L33igh]

Thanks Matt! You have confirmed alot of what I have learnt so far. As far as Im aware, the diff does have have an ABS style sensor as per GTR transfer case, which samples at 100 times per second, sensing loss of traction, and delivers a pulse to a solenoid which in turn applies hydraulic pressure to the diff. (As read in a HPI mag some time ago)

This in theory sounds like the perfect set up for a jekal and hyde diff!! Will drive Bessy to the bowling green gently round corners and when coaxed it will lock up and haul arse sideways!....maybe its too good to be true. It would seem that the 1.2mm shims that I bought to shim the diff are now useless to me, so I am now pinning my hopes on a mate of mine who works for a hydraulic firm here in Mildura. He too believes that I have a crook solenoid and is going to pull the system apart on a test bench and sort it all out. I'll keep you posted. If all goes pear shaped, does anyone know where to find a reasonable priced KAAZ or Cusco, (or equivelant) 1.5way LSD.

...and a final question....is there any extra skill required to drive a 2-way on the street?

[mattymagoo22]

don't pull out yet man the shims may work, it has to be a clutch type LSD if it requires LSD oil so shimming it up may work!!!! so when you've got it pulled out let me know how it goes because if it works the same system that the attessa for 4wds then it should do a good job of locking the diff.

Your mate should be abble to apply pressure to the actuators and see if that works you may just need to bleed your system. you should be able to check it on the bench.

If you do find an aftermarket diff (KAZZ CUSCO) that will fit in I'm thinking that they are the same size housing and everything I want one too but as i said before they may differ in dimensions.

2-way diffs are nowhere near as smooth as the car is now and its "FUN" in the wet thats the only problem just gotta be careful when it rains, when on decel it will kick out/spin.

[MANWHORE]

I also have an a-lsd, and like you I find the same thing.

MY system is working properly. The ALSD light never comes on. The slip light comes on when you spin the wheels.

But I find the diff very lazy. If you're doing a massive burnout, it will turb both the wheels, but normally it generally open wheels.

I have changed the diff oil - no metal shavings, which means it's not doign anything. Also changed the transmax z in the boot reservoir.

Didn't do anything.

Im really interested in the results how you go.

[mattymagoo22]

no metal shvings doesn't mean your diff isn't shagged. cltuchs are made out of friction material. I think that the main prob is clutches and air in the system (hydraulic). is attessa lazy as this diff is the same sort of fuction as the AWD system on GTR's.

[MANWHORE]

No one actually knows much about how the alsd system functions. paul r33 has done some tests with rigging a switch to keep the pump running, but that's it.

No one has taken it apart to inspect how it works etc

[L33igh]

Hmmm...to fix or not to fix....that is the question....I have been offered a complete diff, carrier and all, with a 2-way KAAZ center for $1000 plus my diff in exchange. My fear is that this guy is swapping with me because he has found it basically 'unstreetable', and or it is damaged, (as its not in the car I cant test drive it) maybe pre-loads not set correctly if he did the transplant himself?...Are there common problems with these diffs I should know about before shelling out the cash for this deal, and is it a good one at that?

[180or200]

the KAAZ 2 way is a tough unit, can be a little annoying on the street, it grabs a little too often but when you want the grip its awesome! since changing the oil its much nicer to drive, you really need to coast on tight slow corners or it sounds like its going to jump out! the KAAZ dealer here in Adelaide recommended i use castrol SAF-XA 80w-140 fully synthetic, its less than half the price as the KAAZ oil ! should drop oil every 3-5000 kms to keep running smooth!

[MANWHORE]

yeah, but the thing is, how do you know that it'll bolt into your car?

You might have to change the shafts too and everything.

there's no way that the guy would be serious about swapping that diff for your alsd. He won't be able to get it working in his car. you need the g sensors, etc.

there's the tank inside the boot, all the lines running around, wiring, different cluster. There's a massive amount of stuff.

[mattymagoo22]

no need to pull apart to know how it works, there are clutches and hudraulic actuators that are driven by the pump that lock the diff (or let it open wheel).

there ain't much to the mechanical side of things its the electrical side as there aren't any wiring diagrams readily available.

Cheers Matt.

[MANWHORE]

oh ok, well, you know what would be awesome. You know how there are attessa controllers?

It would be really good if we could make the diff much more ready to lock.

maybe an attessa controller might even work for this application

[mattymagoo22]

yeah not a bad idea. I still haven't got mine to fuction as it should not that I know how it should function (how well, how quick) I've manually run the pump and bled the system still no workies. when I drained my diff oil there was no trace of any hydraulic oil in it so the actuators didn't appear to be leaking.

I'm keen to pull it down and check it out, even though the electircs don't work I'd just set up a switch to operate the pump, but itS my daily driver... (read lazy so and so) and at the end of the day if I got a Kaaz 1.5 way or similar and got rid of the pump lines resovoir along with my hicas theres probably 50 kgs to be saved there and not a hint of single wheeling (yes please). But whos to say that these diffs dont lock and stay locked solid.

DOES ANYBODY OUT THERE HAVE A WORKING A-LSD SYSTEM???????? IF YOU DO DOES IT WORK WELL?

Cheers Matt.

[MANWHORE]

Oh, mine works man. I'm just looking for more performance out of it.

Are you in sydney? if you want, I can take you for a burn in it (not this week - turbo is out atm). But once the turbo is done.

if I get up onto one one wheel when going up a driveway, and persist, it goes chirp chirp chirp and goes forward.

I have changed the diff oil and also done the hydraulic bottle in the boot.

I'm just looking to get it more lock happy.

At the end of the day, it is a mechanical diff.

I don't see any point in taking out one mech diff when you already have a mech diff.

i'll stay tuned to see your results.

you in sydney? if so, i'm happy to give you a hand, and see what results you get

[MANWHORE]

ps: the reason why I said take it above apart was not to 'see' how it works as such. I know how it works theoretically.

but maybe, by taking it apart, there may be a way to remove the hydraulic fluid actuator system, such that the locking is controlled just like a normal mech diff

edit oops: I should have read above. That's what our good friend in mildura is doing.

I'll watch very keenly

Edited February 20, 2007 by MANWHORE

[mattymagoo22]

there are no cones or cams to induce the clutches into a friction state the locking on this diff relies solely on the hydraluic pressure applied on its actuators like in an auto tranny. It is mechanical but it is not mechanically actuated, it is hydraulicly actuated so you can't really do much but shim it so that it has less area to move till it gets friction.

Yeah man in syd will PM you.

Cheers Matt.

Edited February 20, 2007 by mattymagoo22

[mattymagoo22]

hey man whore I reckon if we bled yours at the nipple on the diff it might engage a bit harder....

[MANWHORE]

After researching long and hard, I worked out that the fluid to use is Castrol transmax Z. It's pretty expensive shit. About $18 a litre.

You wouldn't believe it, but I've done it already.

That is, unless if the procedure that you're thinking about using to bleed is different to what I did?

Basically, following instructions from many people that have bleed their gtrs attessa system, they reckon that the boot bottle is just gravity bled.

All I did, was keep the cylinder topped up, and crack the nipple, and kept topping it up. I never let the fluid level go below half.

Unless we've missed another nipple to actually 'bleed' the system, because as far as i'm aware, the one on the rack is the only one.

edit: forgot to mention, that I did this literally about 1 month ago. IMO, it didn't really do anything. The old fluid was of a very similar colour. You know how after like 10 years, powersteering fluid goes black? the fluid in my system was nothing like that at all. It was basiaclly brand new. Just like the stuff in the bottle.

Edited February 20, 2007 by MANWHORE