Originally Posted by Ammofirst
Originally Posted by 1JZ_E46
Haldex is just an electronic clutch pack that sits between the transmission and rear differential (it's dry, not lubricated by gear oil). I would be very surprised if the rear diff is anything but a standard open design.
Look into what sort of differential it is. If it's not a clutch type, it's probably just 75W-85 or 75W-90 GL-5 oil in there.
Edit: perhaps it's. GL-4 75W-90?
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4630859/Had_to_service_a_Cadillac_SRX_
And the Haldex unit may have oil in it.
The Haldex unit does indeed take lubricant.
For the AWD system there are a total of three holes that need fluid. 1. Rear diff. 2. The Haldex unit. 3. The transfer case.
We have a Buick Regal with this AWD system. After doing this a couple of times this is what I've learned : For fluids go to Ebay you can typically find stuff for half off. 1. In the rear differential I've used the synthetic chevron 75w-90 at AutoZone for about eight bucks a quart. Then I purchased the GM factory Limited slip additive and blend it at the proper ratio. 2. For the Haldex unit stick with the factory GM recommended fluid. Unfortunately there is no drain plug but I've had success just pumping out what I could through the fill plug and then adding in the same amount I took out. It wasn't much maybe 8 ounces maximum. 3. Don't forget the transfer case also known as the PTU, that unit does have a drain and fill plug, again use the factory recommended GM fluid.
THANK YOU AMMOFIRST!!! I've got a '14 Regal AWD and finding any information about the fluids this car takes is tough!