Rear differential (RDU) fluid? Amsoil alternative?

[edyvw]

People like you clearly have a hard time reading. I already stated in my original post that if I have to use the OEM RDU fluid I will, and based on the replies here that's more than likely what I'll end up doing until a (trigger warning) higher quality compatible fluid is presented.

There you go.
And you will never know what is going on in reality.

But take into consideration one thing.
At the beginning of 2000, when VW introduced the Borg/Warner Dual Clutch transmission, they had a fairly high failure rate. They used full synthetic, PAO, and ester-based fluids. The solution presented itself in a semi-synthetic fluid that Pentosin developed.
And no, those transmissions that guy talks about do not fail because of fluid. They fail because, well, they are just bad.

 

[Hootbro]

Necro bumping this a bit but would put in my 2 cents in that on my wife's Bronco Sport, at 15K mi, replaced the RDU fluid with the correct Motorcraft XY-75W-QL fluid which I had no problem when I originally bought at $28 a quart.

About 3 months ago at the 30K mi service, the Motorcraft XY-75W-QL fluid had jumped to $42 and I was not going to be paying that nonsense. Searched high and low for a published alternate and could not find one either. Best speculation on the Motorcraft XY-75W-QL fluid is that it was just a 75W GL-4 fluid with a friction modifier added for the clutch pack of the RDU.

So I decided to use Ravenol 75W MTF-3 fluid and added 2oz of friction modifier when I serviced the wife's Bronco Sport RDU at 30K miles. To date and with about 10K miles on it so far, has performed with no issue or clatter. Will inspect the magnet on the drain plug at next RDU service and barring any unusualness, probably will repeat the with the Ravenol or other brand 75W GL-4 fluid and dose with friction modifier again going forward.

 

[Killer223]

correct me if im wrong.but ins't there a law about manufactures requiring you to use their fluid, then they are required to give it for free? something about tying warranty to upsales?
i kinda remember reading about it, they are required to post a spec, so you can source your own product.
i could remembering wrong.

 

[Hootbro]

correct me if im wrong.but ins't there a law about manufactures requiring you to use their fluid, then they are required to give it for free? something about tying warranty to upsales?
i kinda remember reading about it, they are required to post a spec, so you can source your own product.
i could remembering wrong.

Loosely the Magnuson Moss Warranty Act has that kind of language.

The reality is that they do not use terms like "required" but "recommend" fluids meeting their spec instead and with additional language in the warranty terms that failures arising from use of non recommended fluids not meeting their spec is grounds for warranty denial.

If no other aftermarket fluid maker comes to market stating they meet the OEM spec, it is not on the OEM to still have to provide the fluid free of charge.