How can I tell what kind of axles I have?

[fbc]

The manual specifications say:

Rear axle fluid:

Motorcraft SAE
80W90 Axle
Lubricant - for vehicles with conventional axles.
​

or

Motorcraft SAE
75W140 High
Performance
Synthetic Rear
Axle Lubricant - Ref to footnotes 2 and 3 which read:
2 Vehicles equipped with 4.0L SOHC and 4.0L EI engines may have a limited slip differential. If your vehicles is equipped with a limited slip differential, add 4 ounces of additive friction modifier C8AZ-19B546-A, Ford specification
EST-M2C118–A, for complete refill of 8.8 inch and 9.75 inch rear axles.
3
Vehicles equipped with 4.0L
SOHC or 4.0L EFI engines and
3.73 or 4.10 rear axle ratios or
5.0L engines require synthetic rear
axle lubricant. Rear axles
containing synthetic lubricant are
lubricated for life. These lubricants
are not to be checked or changed
unless a leak is suspected, service
required or the axle assembly has
been submerged in water. The axle
lubricant should be changed any
time the axle has been submerged
in water. For Traction-Lok rear
axles, add 4 ounces of additive
friction modifier C8AZ-19B546-A,
Ford specification EST-M2C118–A,
whenever the lubricant is changed.
​

Can this crap get any more cryptic? They forgot to through in that it can only be done on a sunday before a full-moon in the month prior to a leap-year.
!@#$!!!!!!!!!

Can they just say if your rear axle is this type, buy a bottle of X. But no... they need to add friction modifiers with certain specifications, and tons of other crap!!!

damn, I'm on a rant today.

 

[my pos mounty]

Its easier than you might think.
Open the drivers door. Look at the label. Under the heading "AXLE" if it is two numbers, you have an open diff, if it starts with a "D" you have a limited slip.
Your front diff is always an open diff.

 

[corkey]

just ask,

front axle,, d35 ifs,,
rear axle, 8.8 ford,

now as asked open the door, and get the axle code, post it here we will tell you what it is,,

 

[fbc]

D4, limited slip I guess.
Based on the footnote 3 I should never have to change it.

I prefer to change it.. i don't like throwing caution to the wind. Especially on something as costly as an axle.

Is there another 3 party source for this Friction modifier stuff? or is the stealership the only way?

 

[corkey]

friction modifier is available at any parts store,,

 

[my pos mounty]

D4, limited slip I guess.
Based on the footnote 3 I should never have to change it.

I prefer to change it.. i don't like throwing caution to the wind. Especially on something as costly as an axle.

Thats a good idea. You have to wonder just whos lifetime were they referring to?

Is there another 3 party source for this Friction modifier stuff? or is the stealership the only way?

There are some good replacement diff oils that claim that you do not have to add a friction modifier.
I believe that Lucas and Mobil 1 both say that.
I changed the rear lube in my 350 (Limited slip) with Lucas and have had no issues as far as not adding the fricition modifier.

 

[safn1949]

Good place to ask this,why would I need to use synthetic in my 2000 AWD if I have open diffs? Doesn't seem necessary to me.And it's damned expensive.

 

[corkey]

be even better to ask in your own thread, but it will save fuel as it stays cleaner and stable longer, and the shear tendencies are less, so it protects much better,,