Replacement / Repair Of Vspec Diff

[paulr33]

also noticed that you must let it warm up and get some heat into the diff before trying to lock it and go sideways. if you dont it just single spins.

its only when the fluid is warm and been locking for a bit that its ready to lock. i tried a lock last night and it just single span for a good 10 seconds.

but that was with cold diff and fluid

[MANWHORE]

Paul, after that removal and refit, did you change the fluid and bleed the system?

Can you once and for all confirm that it is indeed attessa fluid and also the procedure about how to bleed it?

[paulr33]

yeah the diff place refitted it and flushed out the diff centre and cleaned it up.

they mentioned putting syntheic something orrather in it.

i dont know how to bleed it, but there is a bleed nipple right next to the pump. im not sure if its attessa fluid that you put it in, it makes sense to be attessa fluid. it wasnt a direct oil taste (i smelt and tasted it) but more like an lsd fluid, i guess.

[MANWHORE]

There's no point cleaning the 'stuff' in the diff centre.

that is just your standard diff oil. If you just change that a couple of times, it'll be clean. I've done that on my car a couple times already.

The thing that is sitll puzzling me is the oil feed system - not the diff itself.

[paulr33]

nah they did it anyway as they had it apart and were putting it back in. i didnt ask them to do that, was just part of the pull apart and diag. yeah it could just be standard diff oil, im not sure but that makes sense.

what is puzzling you about the oil feed system?

ill do some testing tonight, ill see how long i need the pump bofore the diff and fluid is warm, warm enough to make it lock. hopefully about a minute of driving with the pump on is enoguh to warm up the fluid

[Beer Baron]

man that is a lot of effort to achieve a result that is almost as good as a stock GTR diff or aftermarket LSD. seems like this option may be more trouble than it's worth.

[paulr33]

well some may think so, but for me i wasnt prepared to spend some cash on a new diff so im kinda stuck with what i've got. all in all, its a lot better

once ive got a pressure guage on the oil feed ill be happy and feel safe so that i can monitor pressure.

[Beer Baron]

yeah for sure you did the right thing. I just mean it's a lot of complexity (on nissans part) for an end result that is about the same as a nice mech LSD.

[paulr33]

yeah me and the guy who helped me hack it (bennett) were having the same discussion, we came up with

1) why is it so compicated

2) why was it such a special factory option

3) why an extra 5k (apparrently) ???

4) why not just a good mech diff ?

we couldnt see any logical reason why they made it how it is, a computer controlled oil pump to lock the diff.

why such expensive parts for a simple feature really, provide a good limited slip diff.

[MANWHORE]

It's sorta like the attessa. It is just a gay oil pump controlled unit which directs power to the front wheels.

They could have just used a centre diff and made it full time awd.

The A-lsd is supposed to be better.

[MANWHORE]

the thing that is still puzzling me and always has been is this:

New Attessa fluid isn't black. Every A-LSD car i've seen has black fluid - mine included.

How do you bleed it - I'm talking proper nissan manual pages.

And also, evidence of what fluid to use. not just I think it is powersteer.

No one on sau has been able to answer this yet.

I'm still ocnfused.

[paulr33]

no idea. i could get some of the oil taken out and tested to see what fluid it is or i could just ask whoever changed it last what did they use.

also tonight, turned pump on warmed it up.

pump on, got pressure to higest (sensor goes off, and kills a-lsd)

take off, diff locks but i get EXTREME axle tramp

like violent. so its locking, but now i have suspension gayness

[paulr33]

more testing and playing around. it doesnt seem that crash hot on locking when going sideways. and it also seems to be be much better when its warmer/hot. i did some reading and found some pages about the right fluid to use in the gtr 4wd system. i have a feeling ive got shit fluid in the resivour and pump so im going to change it to gtr 4wd stuff. more to come when i change the fluid

[paulr33]

1. undo nipple next to the a-lsd pump

2. a bit of fluid trickles out

3. turn car on, left a-lsd pass diag

4. run pump manually

5. wait for trickling to finish

6. check that a-lsd resivour is empty

7. close off nipple

8. put in new castrol transfer max Z

9. top up to max line

10. put cap back on

11. go for a drive

12. experience correct active lsd locking operation

the diff operates like a brand new locking diff now.

it locks each time perfectly in computer mode and does prefect gliding.

no need for the manual switch anymore as it operates spot on with the a-lsd puter driving the show. i am amazed at how much of a difference that has made to my car.

it seems there was a big air pocket in the system and bleeding it has taken that out. im bleeding it again to cycle out the bad fluid. the fluid that came out was brown/orangey.

the new stuff is a new bluey/green. so ill flush the current mix out again and hopefully have a close as possible 100% fill of castrol transmax Z.

the gtr transfer case uses the transmax Z stuff which is actually automatic transmission fluid

[paulr33]

the left over fluid is for sale

http://www.skylinesaustralia.com/forums/in...howtopic=131160

as i dont need it anymore

[MANWHORE]

I don't understand.

So you undo the nipple - won't air get in if only a little bit trickles out?

how do you run the pump manually?

So does it feel much much tighter after bleeding the system?

Where did you find out from that the system uses that trnasmax z and where did you find the procedure the bleed it? I've looked in all the service manuals.

[Snowman]

The transmax z is my secret. The getrag in the R34 GTR uses the same oil as the main gearbox oil - and the getrag in the R34 is for all intesive pruposes the same gearbox as used in the TT Supra - and the Supra people over in the US were kind enough to tell us that the Toyota V106 and the Nissan what ever it is - is just Castrol Transmax Z rebadged.

[paulr33]

yeah the service manuals dont cover the vspec system at all and how to blee d and diag it. since more testing i am back to intermittent locking agian. some times it locks, sometimes it doesnt. the first time i bled it and put new fluid in, it was ace and locked perfectly. now that ive redone it again its intermittent. so im bleeding it incorrectl. you can run the pump by either turning to ON (without starting) and leti it prime or i can turn my switch on which runs 12v direct to the pump.

[MANWHORE]

Luckily I didni't try and bleed it. I'm so excited and it's difficult to wait.

I think the problem is that when you open the nozzle and the fluid is only randomly trickling out, air can get back in.

On the attessa systems, there's a bleeder plug, which you have to undo. After you undo it, once you open the nozzle, the pump runs and pumps the fluid out.

The A-LSD must have somethign like this.

I'm still tryign to find a manual that does haev the system. I only ahve the r33 normal one and the r32 gtr manual.

If someone has the r33 gtr vspec manual or r34 manual, that'd be ace.

[paulr33]

by all means wait until i completely sort it out and get it working 100%

i checked the resivour this morning and its well past max. approx 5-6cms over max so the fluid is way out of whakc. ill bleed more out today when i get home. yeah a mate said there should be a nipple on the diff housing somewhere but there isnt and the fast diagrams dont show one either. only one nipple below the resivour, next to the pump

ive got r32 gtr workshop, r33 workshop and r34 workshop

none of them cover vspec or active lsd