Diff Oil

[banhzSIIR33]

hey there everyone... im pretty new to the skyline scene, but have been a turbo car lover for a very very long tym... and have just picked up my r33 s2 last week...

its a bit clonki when i change gears... even if i try to rev match it... have to get it pretty much spot on for small clonk... wen warm clock is not as bad... but still there... i've tried to look up threads about diff oil but i wasnt very clear to me..

anyways... i just did the engine oil (motul 8100 x-cess), oil filter (cheapo ryco), and gearbox oil (castrol vmx 80) change today... and i was wondering if castrol syntrax 75w-90 is ok for the diff? i noe its pretty sweet as gearbox oil...

i went to sprint... and asked them if they had any syntrax.. which they didnt... they told my syntrax was only for the gearbox and i couldnt use it in da diff... and tried to sell me some titan semi-syntheic shit...

so then i went to supercheap and found some syntrax... and asked the dude working there if it was ok for the diff... and he also said it was only for gear box... and didnt really seem to know much about our beloved imported cars...

so finally... i went to parts boys (another auto shop)... and asked them if syntrax was ok for the diff? they also told me no... and told me to buy some other shit i never seen b4...

so i just gave up and decided to ask all you skyline freaks b4 i go ahead and buy some crappy crap from some dude dat doesnt knwo what he's on about...

any help would be much appreciated...

[MrStabby]

Dude, just check the castrol website for this soft of info.....

Off the top of my head (could be wrong, so double check), synTRANS is recommended for TRANSmissions, and syntrax is recommended for diffs. Generally GL4s are better for transmissions and GL5s are better for diffs, just make sure you get something that's suitable for LSD if you have one.

If your gearbox is getting tired, many here have found that Redline lightweight shockproof has helped - it aint cheap tho.

[SteveL]

As far as I'm aware R33 GTSt uses viscous LSD, so any ordinary name brand non-LSD diff oil of the recommended viscosity range will be fine. Castrol Syntrax will be OK.

Usually there's a sticker on Nissan diffs saying whether LSD oil is required, but, if your not sure, use an LSD oil. It costs roughly the same and using it won't matter at all in a non-LSD diff.

Edited April 10, 2009 by SteveL

[reNEGaDe88]

I am not sure now. I have done heaps of reading up on DIFF oil. But I am not sure what to use.

I have a R32 GTST factory VISCOUS LSD rear diff, but R33 GTST engine and box.

Some workshops recomend Motul Gear FF-LSD Type 2 Oil. But its not an active LSD, so it doesn't need the friction modifiers that 1.5 or 2 way LSD's need. The vicous oil that makes the LSD lock up it seperate to the other oil in the diff.

So do you a slippery oil to allow the diff to spin nicely and not wear, or do u need a sticker oil for the diff to stay lube'd up when u thrash it?

Otherworkshops recomend Castrol SAF-XA or LSX90 or Syntrax or EPX80w90 or VMX80.

Nissan recomend 75w90 oil for the gearbox, similarly the diff. So would running a 80w140 oil be bad?

Other's say that Redline lightweight shock proof is also good. But that stuff is very slippery and has had peoples diff's lock up too much around round abouts etc.

Motul 90PA Differential Oil is what I plan to get, its a good mineral oil, I don't know if fully synthetic is necessary for a factory VLSD.

Whats your opinion?

EDIT: These diff's are hypoid right, so do the oils need to specify that?

Edited May 9, 2009 by reNEGaDe88

[SteveL]

The viscous oil that makes the LSD lock up it seperate to the other oil in the diff.

You've answered your own question......a viscous LSD centre is a sealed unit and the oil used in that type of diff only lubricates the bearings and gears and that's why an ordinary non-LSD diff oil will be fine in your case (as it will be for all viscous LSD diffs). Using an LSD oil would also be fine, but not necessary.

The CWP gears in diffs are of the hypoid type, so using a specific diff oil is essential (GL5, I believe). In terms of brands, I've used Penrite mineral oils for, literally, decades without a single problem, but other name brands like Castrol, etc, will also be fine. If spending lots of $$ on 'exotic' brands makes you feel better then go for it, but, personally, I'm not convinced that oil 'quality' is directly proportional to the amount you spend.

In terms of synthetics, I've had some discussions with Penrite techs (not salesmen) and, generally, synthetics are recommended for high load/temperature operation (eg racing applications, high HP street, etc).

[some_cs_student]

Castrol have a technical help line, why not give them a call and ask? Its on there website

[reNEGaDe88]

Couldn't find the number on teh castrol website.

I got some Motul Gear 300 oil which is fully synthetic ester oil which is $40/L, so ~ 80$ for the diff oil change. But that is only done every 80,000km so its fine. Will let you know how it goes when its in.

[08r3308]

Manual Transmission = Castrol Syntrax 75W-90

Differential = Castrol SAF-XA

[some_cs_student]

Couldn't find the number on teh castrol website.

Expert Advice -> Contact Us -> "You can aslo (sic) call the technical helpline on 1300 557 998"