...Now i'm wondering if a VSLD can actually be "Worn" or is it just the Differential Oil that needs to be changed?

 

Why would you rebuild a vlsd? Just get a real LSD and call it a day.

 

Yes, a viscous limited slip unit can definitely be worn. They are a sealed unit contained within the pumpkin that does not share the regular diff lube used for the ring and pinion gears. With time and abuse their sealed silicone fluid will eventually break down causing a loss of it's ability to transfer torque properly. They are not serviceable. If they get bad enough, they need replacement.

I would imagine cost would be the most likely reason someone would REPLACE, not rebuild, a viscous unit. For those not really needing and/or utilizing a LSD, they are substantially cheaper.

 

How about the Diff OIl ,...when should it be replaced , and if Old could that also be the reason for the VSLD not working properly ??

 

Like I said, the VLSD unit within the diff is a sealed unit with it's own special self-contained lube. It does not share lube with the rest of the diff so changing diff oil does nothing for the vlsd unit. And again, the VLSD unit is not serviceable; just replaceable. I change my diff oil every 30K miles, but unless you're towing/tracking/sustained high-speed driving it, then it could easily go much further between intervals than that.

 

Oh OK got it !

Is VLSD "Wearing" a common problem with G35-37 RDW ??

Called Infiniti ,they said they never replace Diff due to problems??

I've read that after about 60K miles most VLSD no longer work??