VLSD makes niose

[Dattebayo]

My J30 diff has been installed, and i notice that there is considerably more noise coming from the rear end when i am in motion. Sort of a hiss-whirring noise, but only over 20mph. I have the open diff's cover on it and filled it with the diff on the car. I'm wondering if i am putting the right amount of gear oil in it or if there is something else i should be aware of. FSM says it needs 1.5 litres oil (1 and 2/3 qt) in the 240's R200V, but J30 might be different...

[spitz7985]

my stock s13 vlsd makes the same whirring noise. i think its what the diff sounds like when its old and the viscous fluid is starting to break down.

[Dattebayo]

err... i just changed the fluid. i hope the viscous coupling isnt going bad.

[spitz7985]

you changed the oil. the viscous fluid is what breaks down with age/use. they are two seperate fluids.

[Dattebayo]

yowsa. can u chabnge it or do i have to get a new coupling?

[spitz7985]

first of all, i'm not 100% sure that the sound is the fluid going badall i know is my diff never made that noise, then i started to notice the whirring and thats when my lsd stopped working in extreme cases, like when i was stopped, turned the steering wheel all the way to one side, and gassed it, trying to kick the tail out. it still limits slip in a straight line and around most turns, however.

second, i don't think you can change the fluid or swap out the coupling, but i am also not sure on that.

[Dattebayo]

OK. I will check on the coupling. Thanks for the info.

[NeedCAforS13]

you have to add something to the gear oil with a vlsd. you can get it at your nissan dealership (or probably an autoparts store too) its called "vlsd gear oil additive" I think. It supposedly makes them quieter:) I used it on my vlsd, but mine wasn't noisy to begin with...

Sean

[Dattebayo]

I swear i was told a hundred times that you do not need to add lsd additive to vlsd's. I need a moderators opinion here. I hate that noise.

Oh and by the way you can order a new viscous coupling, but you should change a set of bearings and washers with it...

[NeedCAforS13]

We add it to every pathfinder, truck, etc... at Nissan during a diff. service, and they all have the orange "VLSD" stickers on them. I'm pretty sure it says "vlsd additive" on the bottle too, but I'll check for ya next time I go into work:)

Sean

[HashiriyaS14]

OK whats the nissan number then. If i need it then i need it. Or should i just say that some guy from nico told me to get VLSD additive.

[NeedCAforS13]

I'll get you either a part # or an exact name when I work tomorrow:) but if you ask for a vlsd additive they'll probably know what you want...

Sean