BA Farimont diff oil

[hogwort]

Hi all, after a rear suspension rebuild on the BA Fairmont, we replaced the diff oil with a LSD 90 mineral oil. The diff has now a whine (bit like the EX). On other forums it suggests using synthetic. Is this the case??
Thanks as always.

[hoe]

i use synthetic in my fg ute, it has done 460000km and doesn't whine......

apparently the nulon diff oil works well in the ba/bf....

[Godzilla]

If its a LSD, make sure you used LSD oil, dont use LSD oil on a single spinner.

From memory Fraud use a oil additive, you can use one called Sturaco 7098 for LSD models that helps to reduce the diff whinging.

[Mgoldbe1]

Not trying to ask a silly question, but are you sure it's an LSD? They we not standard on BA Fairmont.

[Godzilla]

Not trying to ask a silly question, but are you sure it's an LSD? They we not standard on BA Fairmont.

My thoughts also, and why worded my answer as such.

[mechanic]

I'd suggest that there's a gear/bearing alignment problem with the diff that oil isn't going to fix.
Most diff oils are so similar in makeup that they'd all be suitable for a simple helical gear application. LSD gear oils only have a slightly different shear strength to allow the LSD cones to slip smoothly (anti-chatter).
In my experience the wrong oil won't make enough of a difference to cause a whine - over the short term any way.

[Godzilla]

The BA series of vehicles were known to need addivives to keep them hush hush, its even listed in the service manual under diff fluids....

[Mgoldbe1]

Yes the LSD spec is 40ml of Mobil 3022L 'Friction modifier'

[gordon_s1942]

My Son has a BA so I am noting this in case his ever whines..

I understand an old remedy for Diff whine was a bunch of Bananas, peeled and the skins inserted into the orifice..........
What you do with the fruit is your business...................

[Godzilla]

LOL @ Gordon, yes that was a good old trick.

After checking the original Ford owners manual, Mobil M3022L was used on the LSD as noted by Mgoldbe1 and the Sturaco 7098 was used on the single spinners, not what i had written in my original post which wrote LSD.

[hogwort]

Thank all for your comments. The Father In Law's an old Mechanic & he knows best( yeah sure). He said putting LSD oil in A non LSD diff was ok, though not the other way around. What I put in the diff was Nulon 75W-90 100% synthetic API spec GL5, Gold container. Unfortunately it's still whining, though not as bad. Here is Nulon's blurb off their site.
Full Synthetic 75W-90 Performance Smooth Shift Manual Gearbox and Transaxle Oil
Nulon SYN75W90 is a fully synthetic API GL-5 and API MT-1 hypoid gear oil, providing superior wear protection, excellent low temperature characteristics and high temperature stability when compared to conventional mineral gear oils. It is the preferred substitute for SAE 80W-90 or SAE 90 oil promoting smoother, faster gear changes. Ideal for use in transaxles with combined manual gearbox and hypoid differential. It is recommended for use in passenger cars, towing, 4x4, light commercial and racing conditions

Nulon SYN75W90 is formulated from hydrofinished base oils with superior additive packages to enhance wear protection, corrosion protection, and low temperature characteristics. The optimized formulation has optimum oxidation and thermal stability to ensure fluid durability and performance during its life time.

The hydrofinished base oils used in SYN75W90 is a Very High Viscosity Index (VHVI) base fluids that have advantages of low volatility for better oil consumption, low wax content for improved low temperature fluidity, high saturate level for excellent thermal and oxidation stability, and low sulfur and aromatic compounds for better environment friendliness.

Nulon SYN75W90 is ideal for use in transaxles with combined manual gearbox and hypoid differential. Recommended for use in passenger cars such as Ferrari, Ford, Holden, Lexus, Lotus, Porsche, Subaru and other makes where API GL-5 performance is required. Recommended for use in light commercial and 4x4 vehicles such as Chrysler, Ford, Holden, Kia, Landrover, Mazda, Mitsubishi, Nisan, Ssangyong, Suzuki, Toyota and many other makes where API GL-5 performance is required.

[Godzilla]

Your father in law is correct (sorry to say)

[gordon_s1942]

While us old Farts can be wrong at odd times, Ill bet your Father in Law has learnt not only during his apprenticeship but from under the body repairing or replacing something that didnt work as it should.
While technologies in the motor industry have changed for many reasons, most of what he has learnt, sometimes the Hard way is still relevant today and should be considered and applied to today's vehicles.

And if your Father in Law is anything like me, it does give one a nice warm glow when the 'younger' generation have to admit we sometimes do know what we're talking about, this is yet to happen to you 'in the Fullness of Time'........and it will.