Hi guys, i know i'll find my answer here with your help.

I got my cv boots changed and 1 axleshaft seal changed also. I got my tranny filled back with 80w90 fluid and all that. I spinned my wheels on the car to make sure my tranny was turning the wheels in the same direction at the same time and it was.

My problem is I feel the car isn't pulled by the two wheels at the same time and it spins only one wheels of the line HARD and no sign of locking whatsoever... Out of the blue, 1 out of 50 times, it locks and a feel a thughing in the steering wheel. On the snow, it never locks and 1 wheel spins for half traction all the time. I got the serial number checked by nissan dealership and it is LSD oem.

Is it possible that is worn out or malfunctioning??? liquid level is fine and the liquid itself has a 1000miles on it.

let me know.

 

trans fluid has nothing to do with VLSD working or not. the viscous limited slip diff itself is a sealed unit, with it's own high viscosity silicone fluid sealed inside. VLSDs can and do wear out eventually, and then become just like an open diff. they are not possible to service. your vlsd, if it is indeed behaving like you think it is, is on it's way out. under certain traction situations, there is just not enough viscosity left in the burned up/worn out silicone fluid to make it work. this is probably what's happening to you.

beyond that, VLSDs only transfer between 20 an 30% of the torque from one wheel to another wheel (in good working condition), so this can still give you a 1 wheel spinning situation. so for instance if your car has 200lb-ft of torque and you had one tire on completely dry pavement and one wheel on ice, only 20-30% of your torque would go to the wheel on dry pavement, meaning your car would only accelerate with 40-60lbft of torque pulling it forward meaning it would still move forward pretty slowly and your icebound wheel would still spin pretty severely.

 

Thanks for the explanation, know I totally understand how its made and how it works. Also, my diff bearing and synchros are on their way also, ill rebuilt everything in the spring. OR, is there any alternatives to get a better differencial in the same casing, like taking an open diff and converting it with phantom grip or else???

thanks Nealoc!!

 

Quiffe!!!

 

As 96nismoSE said, there is a Quaife differential that turns up in the classifieds from time to time (IDK if it's available brand new or not) which fits right in and is supposed to be very good.

Or, just pull an open diff from a junkyard car, and weld it. Cheaper, better traction than any type of LSD, and is still pretty streetable. I've been in a 4th gen with a welded differential and aside from a little bit of tire noise when making very sharp turns at low speeds, it functions normally.

 

good idea but do I keep the lsd driveshaft or I need to change for a non-lsd for the welded diff??

 

you can only weld an open diff.

 

Quaife will not go into a VLSD transmission case, you have to install it in place of an open diff. The VLSD and open diff cases are different.

I don't like welded diffs personally, chirping of the inside wheel is annoying to me (we used to weld diffs at the trans shop for those who requested it and refused to spend money on a proper spool or LSD), and in cornering the quaife is better in that it can transfer 100% of the torque to the outside tire whereas the welded is always locked 50-50. You can weld an open diff or a VLSD, VLSD is just harder because you'd either need to take it apart or work really hard to get inside the smaller holes in the basket that the VLSD has as opposed to the big, easy to access holes in the open diff.

Phantom grip style isn't terrible, and works well in certain situations. They obviously are designed to prevent 1 wheel spinning, and generally do a pretty good job. The problem is that if you DO get one wheel spinning often for whatever reason, it's way worse on your diff than if you just got 1 wheel spinning with an open diff. So it makes one wheel spinning less likely, but if it does occur, damage can result (probably not catastrophic, but significantly accelerated wear on the spider gears). They are not a good idea in a car that is run on road courses often for this reason.

Quaife is best, but good luck finding one and if you do, they're expensive.

 

I would also suggest the Quaife. Costs aside from what I hear it's the best overall compared to the VLSD and Phantom Grip.

If anyone is interested in a new Quaife differrential we are still waiting on Cattman for the group deal. He needs 2 more people IIRC to get the ball rolling. I've been on this waiting list since July for the damn differential.

Also Neal do you still work with that transmission shop that does really good rebuilds and such? If you do I would send mine out there or to you to get rebuilt once i get the Quaife differential.

 

I real appreciate your explanations guys, it helps me a lot. thanks.
Ill save cash to get something better but i plan to get the tranny rebuilt also, so welcome the expenses... tchatching..

 

I don't work there anymore but I do have some transmissions left there that I need to build, if you pick up a quaife some time before spring/early summer let me know and maybe we can work something out like putting your quaife in one of the transmissions that I've already got waiting to be put together.