Differential (VLSD) Hissing Noise - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

DirtyS14 · 11-19-2007, 12:32 PM

Yesterday I installed an s13 vlsd from an s13 into my s14. The diff fits in nice and cosy, everything is torqued to factory spec, diff is full with oil. When the car starts moving there's a hissing noise from the back and it gets louder with speed. I only got upto about 30mph before I stopped the car. At 30 its loud enough that you really can't hear someone talking.

I drove with this exact diff in an s13 and it was as quiet as a mouse. I looked under the car and can't see any marks of anything rubbing on anything 'cause that's seriously what it sounds like. The only thing I can think of is this... the s14 has bushings in the front two mounting bolts.. this could hold the front of the diff a little lower... so when i put the s13 (non bushing) setup in, the front of the diff is elevated a little bit causing the diff flange/driveshaft flange to be elevated enough to rub on the body. But thats the thing, I can't see any rub marks on anything in that region.

And yes i've searched like a dog....

Thanks in advance...

Edit: The entire s13 case is in there, I didn't mess around with the internals, just switched the diff covers.

stinky_180 · 11-19-2007, 01:14 PM

i know the s14 front diff mounting bolts are longer then the s13 bolts. did you put the correct amount of fluid into the diff?

MrChow · 11-19-2007, 01:23 PM

^^ how much oil did you put in?

silnismo · 11-19-2007, 01:45 PM

Maybe somthing fell in the diff while installing.

DirtyS14 · 11-19-2007, 02:56 PM

Quote:

Originally Posted by stinky_180

i know the s14 front diff mounting bolts are longer then the s13 bolts. did you put the correct amount of fluid into the diff?

Quote:

Originally Posted by MrChow

^^ how much oil did you put in?

I basically filled it with a syringe until the level came up to the fill nut and it started to overflow... Oh yeah, i used the s13 (shorter) bolts because there are no bushings on the s13 diff. I used 80w-90 GL-5.

Quote:

Originally Posted by silnismo

Maybe somthing fell in the diff while installing.

Yeah but wouldn't that prove for a clunking, locking, exploding situation? All I have here is a hiss.. but I was super careful to not drop stuff into it.

Thanks for your help/time guys!

11-19-2007, 12:32 PM	#1
DirtyS14 Zilvia Member Join Date: Sep 2007 Location: Odaroloc Posts: 190 Trader Rating: (2) Feedback Score: 2 reviews	Differential (VLSD) Hissing Noise Yesterday I installed an s13 vlsd from an s13 into my s14. The diff fits in nice and cosy, everything is torqued to factory spec, diff is full with oil. When the car starts moving there's a hissing noise from the back and it gets louder with speed. I only got upto about 30mph before I stopped the car. At 30 its loud enough that you really can't hear someone talking. I drove with this exact diff in an s13 and it was as quiet as a mouse. I looked under the car and can't see any marks of anything rubbing on anything 'cause that's seriously what it sounds like. The only thing I can think of is this... the s14 has bushings in the front two mounting bolts.. this could hold the front of the diff a little lower... so when i put the s13 (non bushing) setup in, the front of the diff is elevated a little bit causing the diff flange/driveshaft flange to be elevated enough to rub on the body. But thats the thing, I can't see any rub marks on anything in that region. And yes i've searched like a dog.... Thanks in advance... Edit: The entire s13 case is in there, I didn't mess around with the internals, just switched the diff covers.

11-19-2007, 01:14 PM	#2
stinky_180 Nissanaholic! Join Date: May 2004 Location: Pale Blue Dot Age: 40 Posts: 2,064 Trader Rating: (26) Feedback Score: 26 reviews	i know the s14 front diff mounting bolts are longer then the s13 bolts. did you put the correct amount of fluid into the diff? __________________ SoCal RallyX Coverage and MTB Ride Reports WheelsDirty

11-19-2007, 01:45 PM	#4
silnismo Zilvia Addict Join Date: Sep 2006 Location: NJ! Age: 38 Posts: 730 Trader Rating: (2) Feedback Score: 2 reviews	Maybe somthing fell in the diff while installing.