Dif Oil

POELWYK · 22-09-2009, 05:59 PM

hey guys i would just like to know if theres a serten type of oil i need for my dif.
I dont know when it was last serviced so im going to give it a service myself

i would just like to know what people here use and now much am i looking at for it..?

Mr Hardware · 22-09-2009, 06:08 PM

certain
yes
Castrol EPX85 Gear Oil for a std diff

POELWYK · 22-09-2009, 06:14 PM

thanks for that ill go out and get some how much am i looking at for a botle of that

FreddyDUZ747 · 22-09-2009, 06:18 PM

^^^^What he said or any SAE 90W Hypoid gear oil will do.

Around 12-15$ a litre,grab two and that will suffice.

Mr Hardware · 22-09-2009, 06:23 PM

Yeah what gilmore said, they come in 1L bottles at about twelve bucks each or so and i think the service refill is 1.6L or so, so grap two bottles and go for it.

POELWYK · 22-09-2009, 06:30 PM

thanks for the info guys

GK · 22-09-2009, 09:31 PM

This will give you a heads up!

Changing Diff Oil
http://www.fordforums.com.au/showpos...7&postcount=42

All the best with it.

GK

POELWYK · 22-09-2009, 10:03 PM

yeah i just looked at that thanks for the info

blueoval · 24-09-2009, 02:17 AM

I used this oil for my diff when I put it in
http://www.penriteoil.com.au/product...in_gear_oil_80

JC · 24-09-2009, 08:44 AM

Be careful not to spill any of the old oil - it will stink and is hard to get rid of the smell. even the new stuff smells, just not as bad.

Mainlube · 24-09-2009, 09:03 AM

SAE 80w90 and SAE 90 is a little light (even though the book may say to use it) SAE 75w140 would be better, a little more expensive however, you don't need much

And of course ......

Don't forget to flush

Flushing instructions here

Cheers

Steve

JMO · 24-09-2009, 11:52 AM

Can you use an engine flush or is there a specific diff flush?

Erich · 24-09-2009, 05:19 PM

..........

GK · 25-09-2009, 10:25 AM

Quote:

Originally Posted by JC

Be careful not to spill any of the old oil - it will stink and is hard to get rid of the smell. even the new stuff smells, just not as bad.

Truth.

I've not smelled anything to do with cars that's worse!

GK

Mainlube · 25-09-2009, 10:26 AM

Quote:

Originally Posted by JMO

Can you use an engine flush or is there a specific diff flush?

Yes engine oil is fine to flush with, best done not under load (on stands 10 minutes) and a flushing additive wouldn't hurt to help clean as the EP additive in diff oils has often been activated (forms a sacrificial solid boundary by way of oxidised metal surface on the gears ) this give the pungent smell and the dirty coating on the gears seen when viewing / touching diff gears.

Cheers

Steve

Erich · 26-09-2009, 11:55 AM

k - so confirming you can run the car at low/revs - no load on stands full of motor oil for max 10 mins to flush out a non lsd diff - nice

Mainlube · 27-09-2009, 11:44 AM

Quote:

Originally Posted by Erich

k - so confirming you can run the car at low/revs - no load on stands full of motor oil for max 10 mins to flush out a non lsd diff - nice

You could flush / run your T56 / T5 or diff on engine oil for any length of time on stands without load with no damage.

Just be a little aware of back lash slap because of no load through the gear train at very low revs in higher gears while on stands (you will know when you do it) this won't help the drive line.

Revs can be bought up a little every couple of minutes for 15 seconds or so to assist the dishwasher effect.

LSD or not makes no difference to the above procedures.

The smell in gear oil is the Sulphur E P Additive gets pungent when activated.

All machinery gears run on a hydrodynamic film of oil, supposively without any touch.

With gears if you push hard enough and push the oil out of the way (break the hydrodynamic film) and engage a little metal to metal contact the surface temperature (only) elevates past 250 - 300C, this activates the EP additive (sulphur) in the gear oil and oxidises a very thin layer of metal from your gears, this oxidised layer acts as a primitive type of solid boundary to try and stop the gears ripping each other apart. (with sliding wear)

Hopefully you lift the power off or the EP can keep up with the need to make the protective layer or an abnormal wear mode is engaged and damage will start accruing. (with sliding wear)

(now for the plug

)

Mainlube Synthetic Solid Boundary E P Gears Oil SAE 75w90 (T56 & T5) and SAE 75w140 (all diffs) has a purpose built solid boundary additive added to begin with so you can't get metal to metal contact to activate the chemical EP, the Mainlube solid boundary additive brings the weld load of the oil up around 500%.

You don't need an LSD additive with the Mainlube 154 Synthetic Solid Boundary E P Gears Oil SAE 75w140. (75w90 for gearboxes, 75w140 for diffs)

So the stinkier the gear application the more you have activated the chemical EP.

And that's how it all works, no rocket science, just nut and bolts stuff

Cheers

Steve

Dave_Obsession · 28-09-2009, 02:16 PM

Quote:

Originally Posted by blueoval

I used this oil for my diff when I put it in
http://www.penriteoil.com.au/product...in_gear_oil_80

Shav, this stuff looks pretty good - which one did you use??? How much did the 2.5L pack cost?

blueoval · 28-09-2009, 02:19 PM

Quote:

Originally Posted by dave93761

Shav, this stuff looks pretty good - which one did you use??? How much did the 2.5L pack cost?

SIN 80 was what I used. cost about $40-50 from memory. Probably not THE best oil grade to use but Its worked fine for me since putting it in. A bit smelly on the nose but. Dont get any old or new oil on ya, it will be almost impossible to get rid of.

Dave_Obsession · 28-09-2009, 02:21 PM

Quote:

Originally Posted by blueoval

SIN 80 was what I used. cost about $40-50 from memory. Probably not THE best oil grade to use but Its worked fine for me since putting it in. A bit smelly on the nose but. Dont get any old or new oil on ya, it will be almost impossible to get rid of.

Well the Mainlube guys reckons 75w-140 is the go....is there much difference between that and 80w-140??

Oh, and I'd probably pay the mechanic to flush it, especially if it stinks and is hard to get rid off clothes!!!!

blueoval · 28-09-2009, 02:27 PM

well if your going to get a trans place or mechanic to do it, he should know what diff oil needs to go in. Plus he will supply it.

The Mainlube dude should be able to assist in grade depending on your application too.

I would have thought that the 80w is best used for heavy duty work, and towing. The 75w being for general passengers etc.

Dave_Obsession · 28-09-2009, 02:33 PM

Quote:

Originally Posted by blueoval

well if your going to get a trans place or mechanic to do it, he should know what diff oil needs to go in. Plus he will supply it.

The Mainlube dude should be able to assist in grade depending on your application too.

I would have thought that the 80w is best used for heavy duty work, and towing. The 75w being for general passengers etc.

Ah I see, maybe if I can't find any 75w-140, may just go the 75w90 stuff.

Many places (mechanics) overcharge on products....I'm getting my new brakes put on in the next week or so, which is all 'manual labour'....might as well get them to do the diff at the same time, plus if I bring the oil myself, I only have to pay the labour rate!

Mainlube · 29-09-2009, 10:05 AM

The relationship between engine / hydraulic oil's SAE rating IS NOT the same as gear oils, different scale.

SAE 75w90 is 100 cSt @ 40C = SAE 30 engine or hydraulic oil to orientate for you to visualise. (basically gearbox oil, not diff oil) confusing huh?

SAE 75W140 is 200 cSt @ 40C = SAE 50 engine oil or hydraulic oil, this is a diff oil.

SAE 90 gear oil and SAE 50 engine oil is the same thickness in viscosity @ 40C, this is why cSt or ISO @ 40C is far more accurate.

Here is a viscosity chart so you can see there clearly is a big difference / relationship between engine and gear oils.

So, 75w90, 80 and 90 is too thin for diffs if you want the diff to last.

Cheers

Steve

Dave_Obsession · 29-09-2009, 10:17 AM

Quote:

Originally Posted by Mainlube

So, 75w90, 80 and 90 is too thin for diffs if you want the diff to last.

Cheers

Steve

Steve,

(please forgive my ignorant table reading skills if that answers the below question - at work so havent studied it that much!)

So how does a 80w-140 (such as the Pennzoil one that blueoval linked to) fit into the equation???

Mainlube · 29-09-2009, 01:52 PM

Quote:

Originally Posted by dave93761

Steve,

(please forgive my ignorant table reading skills if that answers the below question - at work so havent studied it that much!)

So how does a 80w-140 (such as the Pennzoil one that blueoval linked to) fit into the equation???

Dave

75w140 and 80w140 are almost identical in viscosity

Cheers

Steve

Erich · 29-09-2009, 02:29 PM

Thanks Steve - you have made it crystal clear for me

Ill flush with motor oil (hoisted/no load) and fill with 75w140/80w140

ty again

Dave_Obsession · 29-09-2009, 07:43 PM

^^^^ Agreed.

Thanks Steve!!