[31zook]

I have a very slightly noisy diff in the rear of my Jim, pulled the drain plug out to find black as black oil and metal smear all over the plug... Maybe from running too lower oil, or someone has welded on the housing and had a mini fire inside or what I dunno.


Any ideas fellas?

[sideways]

Collapsed bearings? Not enough backlash?

[DarkHorse]

Wrong oil - too thin and gears wearing each other away?

[mnemonix]

Maybe it's from Windale?

[want33s]

Wrong oil I'd say...

Does it smell like bananas?

[31zook]

Will VMX-80 be a good oil then?

[SierraDan]

i use this one with no dramas

http://www.penriteoil.com.au/products/m ... oid_80w-90

[steve125]

31zook wrote:

Will VMX-80 be a good oil then?

VMX80 is a gearbox oil.

A diff specialist told me to use any 85W-140 that meets the GL5 standard (VMX80 is a GL4 oil).

I use the Pentrite Hypoid stuff.

[monley]

31zook wrote:

Will VMX-80 be a good oil then?

This is what i use to use, but ARB told me to use a 90w LSD oil with the air locker....

[303zuke]

I would prefer to use LSD oil (LS90) in ANY diff; Open, LSD, Lockright or Air Locker.

[whincup]

303zuke wrote:

I would prefer to use LSD oil (LS90) in ANY diff; Open, LSD, Lockright or Air Locker.

can you explain why? i dont understand the difference between the oils...

going off the castrol book at repco & supercheap it says the EPX 80 oil, thats just what they recommend. just bought some today.

[Fatzook]

303zuke wrote:

I would prefer to use LSD oil (LS90) in ANY diff; Open, LSD, Lockright or Air Locker.

X2

80-140 is too thick. It will just rob power.

[31zook]

I'll looK for some 90w stuff then

[Mike57]

The black oil could be from an additive like molybond. This is a molybdenum disulphide (excuse the spelling) friction reducing additive than can be added to gear box and differential oils. I have it in my transfer case to reduce thwe whine and it has had an effect. It is a black graphite type paste that turns the oil black.

[SuziBlu]

Fatzook wrote:

303zuke wrote:

I would prefer to use LSD oil (LS90) in ANY diff; Open, LSD, Lockright or Air Locker.

X2

80-140 is too thick. It will just rob power.

Redline shockproof is equivalent to SAE 30, not much power loss there.

[Mike57]

31zook

Another update on the black oil. I got my 15,000 km service at the dealer this morning and my rear diff oil in my jimny was black. I changed it at 7,500 km myself and it was clear. Since then I did the Mt Dare trip and a few shorter trips. The service guy told me that this was not uncommon and he sees it a lot in the Vitara and Jimny. They always change the diff oils at 15,00 km because of this. He suspects that in the factory they smear or pack the bearings with graphite when they are put together. He assured me it was nothing to worry about. So if your car is new this might be the explanation. If it is old maybe the rear diff oil was never changed or it had an additiive put it in it to quieten it down as I suggested earlier.

By the way I use Castrol EPX 80W-90 but the dealer used Valvoline Duragear 75W-85 in the differential

Mike

[31zook]

Wow, thanks, the things you learn, yeah the oil was a bit low and I wondered if it was stocker oil.... 148000kms and a 99model....

Filling my diffs with airlockers so only want the good oil, 90w still seems to be the general consesus...

[Mike57]

If your oil has been black and low for a long time and it had a whine then you might want to replace all the bearings when the locker is fitted. Sounds like it might have been lacking some maintenance so you may as well get it all checked out while it is apart. Just my thinking anyway.

[31zook]

Not a whine, it's like some other noise I can't put my finger on...

But I'll show the diff bloke and see what he says.